Functionalized silver nanoparticles in lung cancer treatment: mechanistic insights and emerging combination strategies

Abstract

Nanotechnology has emerged as a transformative frontier in contemporary medicine, offering innovative methodologies for the diagnosis and therapeutic management of diverse malignancies. Among various nanoplatforms, AgNPs have garnered significant research attention due to their distinctive physicochemical attributes and potent biological activities. This review provides a comprehensive analysis of the therapeutic potential of AgNPs in lung cancer (LC). We examine the recent advancements in AgNP synthesis techniques, surface functionalization strategies, and characterization techniques that modulate their pharmacokinetics and bioreactivity. The tumor-targeting precision of AgNPs is explored in detail through the EPR effect, along with their cellular uptake and cytotoxic action via oxidative stress, mitochondrial dysfunction, and DNA damage, culminating in the programmed death of lung cancer cells. Furthermore, the review discusses strategies to enhance biocompatibility and tumor selectivity through surface modification with polymers or targeting ligands. This review also evaluates the synergistic anticancer efficacy of AgNPs in combination with traditional chemotherapeutics and hybrid nanostructures, demonstrating improved therapeutic indices and reduced side effects. Despite these promising results, rigorous in vivo investigations and clinical trials remain imperative to validate the long-term safety, optimal dosage, and therapeutic mechanisms of these nanocomposites.

---

1. Introduction

Cancer, a disease marked by uncontrolled cell proliferation and division, has several risk factors, categorized as intrinsic and extrinsic.^1–3 According to GLOBOCAN, the cancers that account for the highest mortality rates globally are lung cancer (18%), colorectal cancer (9.4%), liver cancer (8.3%), stomach cancer (7.7%), and breast cancer (6.9%).⁴ LC stands as the primary contributor of cancer-related fatalities worldwide, with projections indicating approximately 2.5 million new cases and an estimated 1.8 million deaths in the year 2022.⁵ LC is a lethal disease characterized by rapid progression, a high incidence rate, and a limited survival duration. The disease could develop from early to advanced stages within a span of one year after being diagnosed. The patients diagnosed with LC have lower survival rates than those with pancreatic, prostate, colon, and even breast cancers.⁶ LC is primarily divided into two main categories: small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). Different histological and molecular traits serve as the basis for this classification. The occurrence of both SCLC and NSCLC is closely associated with various risk factors, including air pollution, aging, genetic predispositions, pre-existing respiratory conditions (such as emphysema and chronic obstructive pulmonary disease (COPD)), significant tobacco use, and exposure to harmful substances in the workplace.⁷ Additionally, infectious diseases caused by pathogens, such as Chlamydia pneumoniae, Streptococcus pneumoniae, and human immunodeficiency virus (HIV), contribute to the development of LC.^8,9

The therapeutic approaches for LC and its subtypes, specifically SCLC and NSCLC, encompass surgery, chemotherapy, radiotherapy, immunotherapy, and targeted therapy (Fig. 1). The most prescribed standard for LC treatment is surgery, which is not appropriate for advanced-stage and metastatic lung tumors. Historically, the most effective treatment option for lung tumors that cannot be removed due to extensive local invasion or when surgery is unfeasible is the combination of chemotherapy and radiation.^10,11 However, in spite of their potential effectiveness, these interventions carry notable adverse effects, a lack of target specificity, the development of multi-drug resistance, and the possibility of disease recurrence.^12,13 Additionally, studies revealed that radiotherapy should not be the recommended course of treatment for patients who already have significantly damaged pulmonary systems because it damages the surrounding normal healthy cells, which could result in a loss of lung function.^14,15 Similarly, the drugs used in chemotherapy for the treatment of LC are non-specific and impart toxicity towards the normal cells around the tumor growth, resulting in the death of the patient.^14,16 Hence, there is an urgent need to investigate new and safer treatment alternatives.

Fig. 1 Overview of the advancements in nanotechnology-based lung cancer treatments compared with conventional therapies.

A new industry has emerged focusing on the entire modern human production process, specifically the study and development of nanomaterials (NMs), which has been driven by the rapid advancements in nanoscience and nanotechnology.^17,18 NMs can be classified according to their origin (natural or synthetic), chemical composition, material matrix (including carbon-based, inorganic, organic, and composite matrix NMs, or their dimensionality (0-D, 1-D, 2-D, 3-D).¹⁹ NMs, because of their tiny size (1–100 nm), can easily spread throughout the body and pass through biological barriers.²⁰ This has led to a hopeful outlook that NMs could effectively target disease locations, demonstrating significant promise in the identification and treatment of a range of conditions, such as cancer,^21,22 neurodegenerative diseases,²³ cardiovascular issues,²⁴ and infections.²⁵ Metallic NPs represent a specific class of nanostructures made from noble and transition metals, such as silver (Ag), gold (Au), platinum (Pt), copper (Cu) and nickel (Ni). These metal-based NPs have the potential to exhibit various anticancer effects, whether on their own or in combination with drugs or vitamins. A wide variety of nanomaterials, including gold NPs (AuNPs),²⁶ zinc oxide (ZnO),²⁷ titanium dioxide (TiO₂),²⁸ copper oxide (CuO),²⁹ carbon nanotubes,^30,31 polymeric NPs³² and superparamagnetic iron oxide NPs (Fe₃O₄ NPs),³³ have been explored for LC therapeutics. Although each NM offers unique benefits, such as high drug-loading capacity (polymeric NPs), strong photothermal conversion (AuNPs), or ROS-mediated cytotoxicity (ZnO, CuO), several limitations remain. For instance, AuNPs suffer from poor biodegradability;³⁴ CuO NPs often exhibit high intrinsic toxicity;³⁵ TiO₂ can cause pulmonary inflammation and delayed clearance from the lung, especially at elevated or chronic exposure;³⁶ bare Fe₃O₄ NPs can be cytotoxic in vitro, and surface modification is often needed to improve biocompatibility.³⁷ Some carbon-based NMs show long-term retention and biopersistence.³⁸ Therefore, there is a restriction to their widespread therapeutic application.

In biomedical research, AgNPs have drawn attention because of their unique combination of intrinsic biological function and tunable physicochemical properties. Their size, shape, and functionality can be precisely modified through controlled synthesis and surface engineering to improve stability, biocompatibility, and interactions with biological systems.³⁹ In the realms of nanomedicine and drug development, AgNPs offer distinct advantages over other metal NPs. They show antimicrobial, antioxidant, anticancer, and catalytic activities.⁴⁰ Historically, Ag has been utilized in the treatment of skin infections and to preserve drinks in containers for prolonged periods of time. Today, it is being utilized to develop innovative structures designed to fight cancers.⁴¹ Unlike other NMs that primarily function as inert nanocarriers, AgNPs possess intrinsic bioactive properties and can directly contribute to anticancer and antimicrobial effects while serving as platforms for drug and gene delivery.³⁹ In contrast to magnetic NPs such as iron oxide, which are widely used for imaging and targeted delivery, AgNPs exhibit stronger direct anticancer effects without requiring external stimuli. The anticancer effects of AgNPs on tumor blood vessels are linked to their ‘Enhanced Permeability and Retention’ (EPR) effect, leading to their accumulation in tumor tissues.⁴² AgNP treatment effectively suppresses the motility of cancer cells by modulating the activity of matrix metalloproteinases (MMPs), thereby halting the cell cycle and inducing various morphological changes.^43,44 AgNPs also inhibit uncontrolled cell growth via autophagy, necrosis or apoptosis, engaging pathways like NF-κB, COX-2, and PI3K/AKT/mTOR.^45,46 AgNPs are versatile nanostructures that can be easily manufactured in unique sizes and shapes at comparatively inexpensive costs to Au and Pt. Its synthesis follows standard procedures that do not require sophisticated laboratory equipment, and its surface chemistry can be readily tuned to enable functionalization with targeting ligands, polymers, or drugs.^47,48 The optical and electronic properties of AgNPs further enable their applications in diagnostics, biosensing, and bioimaging, supporting early disease detection and monitoring.^39,49 Additionally, AgNPs are increasingly explored in tissue engineering, where they aid in scaffold modification and infection control. Despite these advantages, challenges related to dose optimization, toxicity, biodistribution, low biodegradability, lower predictability of in vivo behavior compared to some alternative NMs and long-term safety must be carefully addressed to enable successful clinical translation, as summarized in the schematic overview (Fig. 2).

Fig. 2 Schematic of multifunctional AgNPs in diagnostic and therapeutic applications.

A considerable percentage of the studies examined (8.34%) discussed the green synthesis of metal-based NPs, while 3.83% specifically focused on the production of AgNPs. Importantly, 13.03% of the articles were dedicated solely to the cytotoxic effects of green-synthesized AgNPs, whereas 39.78% emphasized their antioxidant properties.⁵⁰ Furthermore, 5.29% and 21.8% of the articles investigated the antimicrobial abilities of AgNPs that were synthesized biologically, emphasizing the rising interest in green synthesis for its eco-friendly and less toxic attributes. In contrast, the effectiveness of these NPs against LC and other cancer types was reported in 69.03% of the articles without differentiation.⁵⁰ Despite the many reviews about the general biomedical and anticancer uses of AgNPs, many of them are not focused on discussing disease-specific mechanisms and translational relevance. The present review is distinct in that it offers an in-depth understanding of the mechanistic pathways of AgNPs and an LC-based perspective. In addition, it highlights some of the recent gaps and advances in surface-functionalization methods and combination therapies that would improve the selectivity, biocompatibility and therapeutic behavior of AgNPs. By integrating fundamental design principles with emerging clinical evidence, this review aims to bridge the gap between NM research and translational applications in LC therapy. To enhance translational relevance, a clinically viable AgNP formulation for LC treatment should meet key criteria, including a controlled size (∼20–100 nm), biocompatible surface coating to regulate Ag⁺ release, and a clinically feasible route of administration (such as inhalation or targeted intravenous delivery). Additionally, formulations must be scalable under manufacturing standard conditions and demonstrate a favorable therapeutic window with selective tumor toxicity. These parameters serve as a benchmark for evaluating the current experimental systems discussed in this review.

2. AgNPs: synthesis methods, characterization techniques and physicochemical properties

2.1. Synthesis of AgNPs

The different shapes, sizes and properties of AgNPs are achieved through various synthesis methods. These methods can be widely classified into two fundamental approaches: top-down and bottom-up approaches. The top-down method focuses on the reduction of bulk precursors into nanostructures via various physical and thermal techniques.⁵¹ This method is also known as the destructive method.⁵² The bottom-up method or constructive method involves the synthesis of NMs by assembling atomic and molecular components into larger, more complex nanoscale assemblies through controlled chemical and biological processes.⁵² Further, the synthesis techniques can be classified into three main categories: physical, chemical, and green methods. The characteristics of the final NPs are greatly influenced by the technique selection (Fig. 3).

Fig. 3 Schematic representing the synthesis methods, surface modification strategies, characterization techniques and physicochemical properties of AgNPs.

2.1.1. Physical method. The physical method relies on the physical agents, mainly heat, electrical discharge or electromagnetic irradiation,⁵³ and they eliminate the need for toxic precursors and usually have a rapid processing time. The top-down approach mainly consists of physical methods, such as mechanical milling, nanolithography, sputtering, chemical etching, electro explosion, laser ablation, physical vapor deposition and thermal decomposition.⁵⁴ The physical method produces NPs on a large scale with structural homogeneity and elemental purity. However, the absence of a chemical stabilizer or capping agents poses a significant challenge in preventing agglomeration. Also, a major drawback is their high energy consumption, which makes them unsuitable for treating LC. NPs synthesized through physical methods are generally small (size <10 nm), which increases cellular toxicity due to their ability to easily penetrate cells. This is detrimental to the intended medication delivery system as it may impact both cancerous and healthy cells.⁵⁵

2.1.2. Chemical method. Nowadays, chemical synthesis remains the most prevalent approach for the fabrication of AgNPs. They are further subdivided into chemical reduction, pyrolysis, electrochemical, photochemical, microwave-assisted and sonochemical procedures. The three fundamental components required for the synthesis process are metal precursors, a reductant and stabilizing/capping agents. Ag⁺ is reduced from the silver precursor to the Ag⁰ state during the reactions, which occur mainly in the solution phase. Ascorbic acid, ethylene glycol (ethane-1,2-diol), sodium citrate, borohydride, and hydrazine (also known as diamine) compounds are among the frequently utilized reducing agents.⁵⁶ Nucleation and growth are the two stages of the AgNP creation process. The concentration of monomers in the solution quickly surpasses the crucial supersaturation level, causing burst nucleation and precipitation. The nucleus is created by the precipitation of the monomer, and the repeated nucleation process encourages the constant emergence of additional seeds.⁵⁷ Following nucleation, the increased monomer addition causes nucleus growth and creates NPs of bigger sizes.⁵⁸ Stabilizers, such as polymers and surfactants, are also utilized throughout the production process; they disperse AgNPs and improve their biocompatibility.⁵⁹

2.1.3. Biological method. Biological synthesis follows the green chemistry principles via the utilization of biomolecules, enzymes, various plant materials and microorganisms as reducing and capping agents. It serves as an alternative to other methods that utilize toxic chemical reducing agents and stabilizers. This method has simpler reaction conditions and has almost no environmental toxicity effects, as it uses water as a solvent at normal temperatures and pressures.⁶⁰ Altering the pH of the reaction mixture can change the size and shape of the biosynthesized AgNPs. The reducing/capping capabilities and following growth of AgNPs are directly impacted by the pH, which makes it easier to regulate the electrical charges of biomolecules.⁶¹

2.2. Characterization of AgNPs

A comprehensive array of analytical and spectroscopic techniques is employed to characterize the properties of NPs, including their morphology, elemental composition, surface functionality, colloidal stability, size distribution and dispersity (Fig. 3).

2.2.1. UV-Vis spectroscopy (UV-Vis). An optical analysis of AgNPs is done using this technique, where both qualitative and quantitative information on NPs is provided. It elucidates how surface plasmon resonance affects the size and dispersion of AgNPs. With this method, the sample absorbs UV or visible light, producing distinct spectra. In the 400–500 nm UV region, the AgNPs show high absorption because of the localized surface plasmon resonance phenomena (Fig. 4a).

Fig. 4 Characterization of AgNPs. (a) UV-vis spectra, reproduced from ref. 65, with permission from J Biochem Tech, copyright 2019. (b) FT-IR spectra, reproduced from ref. 66, with permission from Elsevier, copyright 2020. (c) SEM image of Ag nanocubes, reproduced from ref. 67, with permission from ACS, copyright 2006. (d) TEM image with SAED pattern, reproduced from ref. 68, with permission from Springer Nature, copyright 2019. (e) DLS and zeta potential plots, reproduced from ref. 69, with permission from Taylor and Francis, copyright 2016. (f) XRD pattern, reproduced from ref. 66, with permission from Elsevier, copyright 2020.

2.2.2. Fourier-transform infrared spectroscopy (FT-IR). This technique provides information regarding the various functional groups that are available in the sample. The infrared light interacts with the rotational and vibrational modes of the molecules, leading to the stretching and bending vibrations in the 4000–400 cm⁻¹ range. It is used to confirm the presence and interaction of the surface functional groups responsible for the reduction, capping, and stabilization of AgNPs, thereby providing insight into their synthesis mechanism and surface chemistry (Fig. 4b).

2.2.3. Scanning electron microscopy (SEM). This method is used for determining the dimensions, shape and surface morphology of the NPs. A beam of electrons is utilized as an imaging probe for scanning across the sample. It provides high-resolution images by detecting reflected or knocked-off electrons from the surface of the sample. The benefit is that a minimal amount of the sample is needed. AgNPs have different morphologies, including spherical, nanowires, nanobars, nanorice, nanorods, nanoprism, nanocubes, nanoflower, and star-shaped⁶² (Fig. 4c).

2.2.4. Transmission electron microscopy (TEM). This is another effective imaging tool for the analysis of the shape, size distribution and structural arrangement of NPs. It utilizes a transmitted beam of high-energy electrons to generate images that have higher resolution than SEM images (Fig. 4d).

2.2.5. Dynamic light scattering (DLS). This method is used to ascertain the NPs’ hydrodynamic size by passing a monochromatic light source (laser) through a suspension of NPs. Due to Brownian motion, the particles scatter light with fluctuating intensities, allowing the particle size to be calculated using the Stokes–Einstein equation. Also, this method determines the zeta potential (ζ) of NPs, where a large magnitude, either positive or negative, indicates the electrostatically stabilized NPs, which in turn indicates no aggregation⁶³ (Fig. 4e).

2.2.6. Powder X-ray diffraction (P-XRD). The crystalline nature, lattice constant, orientation and average size of the particles are provided through P-XRD. Additionally, it gives information on the phase impurity in the samples. It is useful for verifying the alloy structure of the bimetallic NPs. For the AgNPs, the XRD pattern (Fig. 4f) shows the presence of mainly three diffraction peaks, corresponding to (hkl) indices of (111), (200), and (220), which represent the face-centered cubic (fcc) structure.⁶⁴

2.3. Properties of AgNPs

The AgNPs’ small size and high surface area-to-volume ratio allow them to display unique physicochemical characteristics compared to other NPs.⁷⁰ These physicochemical properties are governed by their synthesis methods, size, shape, surface charge, coating, composition and agglomeration (Fig. 3). Due to their nanoscale dimension and enhanced reactivity and interaction, NPs can be used as a catalyst. In biological processes, the small size of NPs permits deep tissue penetration and absorption by target cells, thereby increasing the bioavailability of medicinal compounds.⁷¹ Que et al. reported that 13 nm AgNPs significantly inhibit the migration and invasiveness of A549 cells compared to larger-sized NPs.⁷² They can be synthesized in different shapes, like spherical, nanocubes, nanorice, nanorods, nanobars, nanoprism, wool-like nanoflower, nanowires, and star-shaped, as shown below in Fig. 5. For the biological systems, the spherical NPs are highly favoured because of the high surface-area-to-volume ratio, and they are capable of releasing Ag⁺ ions more efficiently, showing a remarkable antibacterial activity.⁷³ Additionally, the stability and interaction of AgNPs with other molecules are determined by the surface charge. The surface charge can be adjusted by pH modulation and surface functionalization. In biomedical applications, the surface charge can help in improving uptake, targeting and therapeutic efficiency.⁷⁴ Altogether, these characteristics make them exceptional biological agents for wound healing, antibacterial activity, cancer treatment, biosensors, bioimaging, and anti-diabetic effects.⁷⁵

Fig. 5 Representation of electron microscopy images of the synthesized Ag nanostructures: (a) nanospheres, reproduced from ref. 76, with permission from Elsevier, copyright 2019; (b) nanocubes, reproduced from ref. 77, with permission from ACS, copyright 2010; (c) nanorice, reproduced from ref. 78, with permission from ACS, copyright 2007; (d) nanorods, reproduced from ref. 79, with permission from ACS, copyright 2011; (e) nanobars, reproduced from ref. 78, with permission from ACS, copyright 2007; (f) nanoprisms, reproduced from ref. 80, with permission from RSC, copyright 2019; (g) wool-like nanoflowers, reproduced from ref. 81, with permission from RSC, copyright 2022; (h) nanowires, reproduced from ref. 82, with permission from Wiley, copyright 2002; and (i) nanostar, reproduced from ref. 83, with permission from ACS, copyright 2013.

3. Tailoring AgNPs through functionalization for enhanced therapeutic performance

AgNPs have been found to be interesting therapeutic nanocarriers because of their better physical, chemical and biological properties. However, they are also prone to exhibiting toxicity, limited solubility and stability, which hinder their use in nanomedicine.⁸⁴ To enhance their safety profile, surface modification is necessary. The surface functionalization can be done using polymers, peptides, surfactants, aptamers, biomolecules, fluorescent molecules, drugs, etc., as shown in Fig. 6. This can be done via adsorption, surface coating, covalent and non-covalent modifications and electrostatic interactions using different physical and chemical methods.⁸⁵ Surface modification helps in controlling size and protecting the NPs from the complex biological environments, thereby improving biodistribution, bioavailability and targeting.⁴⁵ Improved cellular membrane interactions, regulated drug release, reduced toxicity, increased therapeutic binding, and enhanced biocompatibility are all benefits of the surface alteration.⁸⁶ However, despite promising outcomes, many reports remain method-driven with limited mechanistic rigor, but collectively, they provide insights into how surface chemistry shapes therapeutic outcomes in LC treatment. Table 1 summarizes the surface-modified Ag-based nanocomposites and their applications for effective treatment against LC cell lines.

Fig. 6 Surface functionalization of AgNPs with various biological and chemical moieties.

Table 1 Comparative overview of various surface-functionalized Ag nanocomposites evaluated for LC treatment, highlighting their composition, size, IC₅₀/LC₅₀ values, and cytotoxicity against LC and normal cell lines

Nanocomposites	Surface functionalization	Category/description	Size (nm)	Advantage of functionalization	LC cell line and IC50/LC50	Toxicity to normal cell line	Ref.
TMC/Ag	N,N,N-Trimethyl chitosan chloride (TMC)	Polymer	11–17.5	Enhances dispersion, reduces aggregation, and increases uptake via positive charge	A549 and 12.3 µg mL^−1	WI-38 (357.2 µg mL^−1)	87
CS@PB-Ag	Chitosan and Piper betle extract	Biopolymer and plant extract	28	Polyphenols stabilize AgNPs and induce ROS-mediated apoptosis	A549 and 180 µg mL^−1	—	88
CS@Ag	Chitosan and Sida acuta extract	Biopolymer and plant extract	6–45	Enhances biocompatibility and reduces nonspecific toxicity	A549 and 34.5 ± 0.5 µg mL^−1	—	89
CA-Ag	Caffeic acid	Ligand	75	Improved solubility and antioxidant protection increase selectivity	A549 and 78 µg mL^−1	—	90
ASNase-Ag	Asparaginase	Enzyme	58	Enzyme-mediated metabolic stress and enhanced cancer-specific toxicity	A549	—	91
AgNPs@Cur@INH	Curcumin and isonicotinic acid hydrazide	Polyphenol and antibiotic	—	Improved mitochondrial stress and apoptotic signaling	LK-2	WI38 (<LK-2)	92
Ag-NCPA	N-Cholyl D-penicillamine (NCPA)	Biosurfactant	9.1 ± 0.6	Thiol-Ag binding improves colloidal stability and selective uptake	A549 and 50 µg mL^−1	—	93
AgPVP, DS@AgPVP, and AC@AgPVP	Polyvinylpyrrolidone (PVP), D. sissoo (DS) and A. calamus L.	Polymer and plant extracts	10–20	Controlled dissolution and enhanced cellular uptake	A549 and 41.60 ± 2.35, 14.25 ± 1.85, and 21.75 ± 0.498 µg mL^−1	WI-38 (420.69 ± 2.87, 408.20 ± 3.41, and 391.80 ± 1.55) µg mL^−1	94
PLGA-Pac-Ag	Polylactic-co-glycolic acid (PLGA)	Polymer	276 ± 2.7	Slow Ag^+ release; high drug entrapment; and improved stability	A549 and 0.798 µg mL^−1	—	95
CMT-Ag	Camptothecin	Alkaloid	10 ± 2	Drug-assisted apoptosis and improved intracellular delivery	A549 and 107.18 µL mL^−1	L926 (>100 µl mL^−1)	96
AgCS-CIS-SCRBD	Chitosan, cisplatin and SCRBD-targeting ligand	Biopolymer, drug and ligand	40–110	Drug delivery + AgNP ROS contributes dual-action cytotoxicity	A549 and 5 µg/100 µL	HEK293 (>50 µg/100 µL)	97
Cum-PEG-BpAg	Thiol polyethylene glycol amine (HS-PEG2K-NH2)	Polymer	27.8	Prevents aggregation and enables photodynamic ROS burst	A549 and 4.014 µg mL^−1	—	98

---

Biopolymer- and plant-extract-derived coatings are among the most frequently explored. Studies involving trimethyl chitosan,⁸⁷ chitosan-capped AgNPs synthesized with Piper betle and Sida acuta extracts,^88,89 and caffeic-acid-functionalized AgNPs⁹⁰ consistently show reduced AgNP aggregation and improved selective cytotoxicity toward cancer cells. These systems likely benefit from steric stabilization, controlled surface charge, and the inherent antioxidant or pro-apoptotic activity of natural phytochemicals, although this synergy is often assumed rather than dissected experimentally. Similarly, asparaginase-bound Ag nanocomposites⁹¹ illustrate how enzymatic ligands can enhance selective anticancer responses through increased metabolic stress in LC cells; however, deep investigations into their NP-enzyme conjugation stability or in vivo behavior are lacking.

Small-molecule functionalization offers additional therapeutic advantages. Curcumin (Cur)-stabilized AgNPs surface-functionalized with isonicotinic acid hydrazide (INH)⁹² demonstrates how dual-function ligands can simultaneously improve particle stability, alter zeta potential, and introduce biologically active sites that modulate ROS-mediated apoptosis. Likewise, AgNPs synthesized using N-cholyl D-penicillamine (NCPA)⁹³ showed enhanced stability and reduced hemolytic toxicity, presumably due to the biosurfactant-like structure of NCPA, which forms a protective interface that limits membrane disruption and excessive ion release. These are some examples of how even simple molecular coatings can remodel intracellular fate, yet mechanistic interrogation remains limited. Synthetic polymers expand functionality further: PVP-coated AgNPs modified with D. sissoo and A. calamus extracts⁹⁴ and PLGA-based paclitaxel-loaded AgNPs⁹⁵ underscore the advantages of polymeric shells in controlling Ag⁺ dissolution, enhancing drug-loading capacity, and reducing off-target cytotoxicity. However, most drug-loaded systems still lack clear benchmarking against free drugs, obscuring the origin of the improved efficacy, whether from NP-mediated delivery or standard cytotoxic drug action. Similarly, camptothecin-functionalized AgNPs⁹⁶ have been shown to demonstrate improved cytotoxicity; however, the study relies primarily on IC₅₀ values, without deep mechanistic evidence of improved uptake, intracellular trafficking, or ligand-receptor specificity. Targeted and stimuli-responsive approaches are emerging, although they remain in the early development stages. ACE2 receptor-directed AgCS-CIS-SCRBD nanocomposites⁹⁷ and curcumin-loaded photodynamic AgNP conjugates⁹⁸ indicate that ligand-mediated uptake and PDT-triggered ROS generation can significantly potentiate apoptosis. Yet, these investigations are typically confined to single-cell-line studies and lack the pharmacokinetic or immunological evaluations necessary for translational relevance. Despite these advantages, the field continues to rely heavily on descriptive synthesis reports, UV-Vis spectra, and IC₅₀ assays, with limited mechanistic or in vivo validation. Greater emphasis on standardized surface chemistry analysis, quantitative mechanistic studies, and reproducible biological models is needed to translate functionalized AgNPs from promising in vitro constructs to clinically meaningful anticancer platforms.

The studies summarized in Table 1 reveal several common trends in the assessment of surface-functionalized AgNP systems for LC therapy. Many investigations rely primarily on a single LC cell line, most frequently A549, which limits the broad applicability of the findings across the diverse molecular subtypes of LC. In addition, comparisons with normal lung cells, such as WI-38 or L926, are included in only a limited number of studies, and the absence of appropriate non-cancerous controls in many reports makes it difficult to adequately evaluate cancer selectivity and potential toxicity toward healthy lung tissue. Another notable issue is the use of relatively high dose ranges in several in vitro experiments, sometimes exceeding concentrations that may be clinically achievable, thereby complicating the translational relevance of the reported IC₅₀ values. Furthermore, although many functionalized AgNP systems demonstrate promising in vitro cytotoxicity and mechanistic activity, only a small number have been validated in animal models. Together, these observations highlight a broader gap between NP development studies and the rigorous in vivo investigations required to support clinical translation.

A comparative assessment of AgNP functionalization is highly dependent on the nature of the surface modifier, with each strategy offering distinct advantages rather than a single superior approach. Polymer-coated systems (TMC-, PVP-, and PLGA-based AgNPs) consistently exhibit enhanced colloidal stability, controlled Ag⁺ release, and improved biocompatibility, often translating into higher anticancer efficacy and lower toxicity towards normal cells. In contrast, AgNPs functionalized with biopolymer (chitosin) and plant extract (Piper betle, Sida acuta extract, D. sissoo and A. calamus L.) provide better biocompatibility and reduced nonspecific toxicity but generally show moderate cytotoxicity. Systems functionalized with ligands (caffeic acid and SCRBD) and small molecules (isonicotinic acid hydrazide) exhibit improved cellular interactions and selectivity, with intermediate therapeutic outcomes. Notably, drug-loaded and -targeted nanocomposites demonstrate the highest potency due to the synergistic effects between the AgNP-induced ROS generation and the drug activity, although their performance is often influenced by the drug component itself. Overall, these findings highlight that the effectiveness of AgNP functionalization is context-dependent, requiring a balance among stability, selectivity, and therapeutic efficacy for optimal design.

4. Administration routes for AgNPs

From a translational perspective, the administration route must align closely with clinically realistic AgNP design parameters, including particle size, surface stability, biodistribution, and safety profile. In this context, inhalation delivery is particularly attractive for lung cancer treatment as it enables direct deposition in the respiratory tract, enhances local drug concentration, and reduces systemic exposure and associated toxicity.^99,100 Alternatively, targeted intravenous delivery remains a viable strategy, especially when supported by surface functionalization to improve tumor accumulation and minimize off-target effects.^101,102 In contrast, commonly used experimental routes, such as intraperitoneal or non-targeted systemic administration, may have limited clinical relevance, underscoring the importance of evaluating AgNP systems within physiologically and clinically feasible delivery frameworks.¹⁰³

4.1. Intraperitoneal (IP)/systemic delivery

IP injection is one of the prevalent approaches used in preclinical tumor models. It enables the introduction of NPs systemically while avoiding the barriers associated with oral drug delivery, and it is less difficult to perform in small animals. In a study that involved the implantation of H1299 human lung cancer cells in SCID mice, green-synthesized AgNPs were prepared using plant extracts and subsequently administered to the mice via IP injection in three doses per week at a body weight of 10 µg g⁻¹. This way, the rate of tumor growth in this intervention group was considerably reduced as compared to that in the control group. This approach provided systemic exposure but not localized delivery to lung tissue, and thus, it may not accurately model the pharmacokinetics of localized lung tumors.¹⁰⁴

4.2. Intravenous (IV) injection

The IV injection technology enables the direct delivery of AgNPs into the bloodstream, where they can circulate and potentially target lung tumors, especially metastases or well-vascularized tumors. However, the systemic application of AgNPs may lead to organ toxicity, inducing adverse effects such as lung inflammation. For instance, a study involving multi-dose IV administration in mice revealed the presence of inflammatory infiltrates and notable structural alterations in lung tissue. Although this method is considered simplistic for systemic delivery, there is a scarcity of direct in vivo investigations regarding AgNPs administered via IV in LC models (i.e., lung tumors) in the existing literature.¹⁰⁵

4.3. Intratumoral/local injection

Direct injection into or around a tumor optimizes local bioavailability and reduces the risk of systemic adverse effects. AgNPs have been evaluated in this manner within immune-sensitization and tumor-control models (these metal NPs have the ability to augment necrosis and immune infiltration when administered locally). Although the majority of intratumoral AgNP immunomodulation instances have been observed in models other than LC models, the underlying principle extends to lung tumors that can be accessed through image-guided injections or surgical procedures, thus providing a high local dosage with diminished systemic toxicity. A recent study demonstrated that small citrate-coated AgNPs measuring approximately 5 nm, when injected around the tumor, significantly amplified immune infiltration and enhanced the efficacy of checkpoint blockade in murine tumor models (this illustrates the promising potential of localized AgNP administration in bolstering anti-tumor immunity).¹⁰⁶

4.4. Inhalation/pulmonary aerosol

Administering AgNPs through aerosolization or inhalation presents the most evident opportunity for targeted treatment of LC. The aerosolized particles settle throughout the airways and alveoli, resulting in elevated local concentrations within the tumor microenvironment while minimizing systemic exposure. Robust methodological examples exist for inhalable nanomedicines in LC (numerous NP types have been developed as aerosols and evaluated in orthotopic/orthotropic lung tumor studies),¹⁰⁷ yet therapeutic investigations specifically employing inhaled AgNPs for lung tumors remain exceedingly scarce.¹⁰⁸

4.5. Intranasal administration

Non-invasive intranasal dosing is an active way of delivering NPs to the upper as well as lower respiratory tracts. This method has been widely applied in the study of the translocation of substances in the nose into the brain and the pulmonary deposition of Ag nanoarchitectures. It is a viable alternative to the treatment of lung tumors in the small animal setting because it is simple to administer, although, because of anatomical dissimilarities between the rodent and human nasal structures, scaling and validation must be carried out before it can be utilized in a clinical setting. Research into the intranasal fate of Ag shows that pulmonary and systemic redistribution of Ag is important after nasal administration, which means that this route could be considered in future studies for local lung delivery in many tumor models.¹⁰⁹

4.6. In vitro route selection

Several in vitro experiments have demonstrated the potent anti-cancer efficiency of AgNPs against LC cell lines through diverse molecular pathways. Green-synthesized AgNPs have also been shown to cause concentration-sensitive cytotoxicity and apoptosis in H1299 cells via the reduction of the anti-apoptotic Bcl-2 and the enhancement of the caspase-3 activity. Similarly, artificially engineered AgNPs made using Alangium salvifolium leaf extract showed a significant anti-tumor effect in xenograft SCID mice by inhibiting the NF-kB signaling pathway through intraperitoneal injection.¹¹⁰ Likewise, biogenic AgNPs synthesized using Alangium salvifolium leaf extract exhibited a significant anti-tumor effect on A549, causing G2/M phase arrest, mitochondrion membrane depolarization, and DNA fragmentation.¹¹¹ Additionally, AgNPs obtained using Albizia adianthifolia caused intrinsic mitochondrial apoptosis in A549 cells through the expression of p53, Bax, and caspases, as well as the inhibition of Bcl-2 and disruption of the mitochondrial potential.¹¹² In another study, eco-fabricated AgNPs obtained using Azadirachta indica, Gymnema sylvestre, and Moringa oleifera were found to have a high antiproliferative activity against A549 cells via the down-regulation of angiogenic (VEGF) and proliferative (Cyclin D1) genes, thus reducing the chance of metastasis.¹¹³ All these findings show that plant-based AgNPs have significant cytotoxic and anti-metastatic impacts on LC cells through apoptotic and oxidative stress signaling. However, the issue of excessive ROS-mediated toxicity, unpredictability in in vivo translocation, unclear mechanisms of NP internalization, and oscillations in green production stability are significant barriers to clinical application.

Preclinical evidence demonstrates that AgNPs can be delivered through multiple administration routes, including intraperitoneal, intravenous, intratumoral, inhalation, and intranasal pathways, each offering distinct advantages and limitations. Systemic delivery approaches such as IV and IP administration enable widespread biodistribution but raise concerns regarding off-target toxicity and organ accumulation. In contrast, localized delivery strategies, particularly inhalation or intratumoral injection, may offer higher NP concentrations at lung tumor sites while minimizing systemic exposure. Nevertheless, most existing investigations rely on preclinical animal models or in vitro systems, and comprehensive pharmacokinetic and toxicity studies are still required to determine the most effective and safe delivery strategies for clinical translation.

5. Cellular uptake pathways of AgNPs: insights into biological interactions

5.1. Active mechanism

The study of the complex mechanisms of cellular uptake, subcellular localization, and cellular retention is essential for the enhancement of the functionality and design of NM-based materials for medical applications. In the case of LC, AgNPs are taken into cells through receptor-mediated uptake, endosome-mediated uptake, and passive diffusion, all of which are mediated by endocytosis, particularly phagocytosis, macropinocytosis, caveolin-mediated endocytosis (CVME), and clathrin-mediated endocytosis (CME).¹¹⁴ The absorption of AgNPs in A549 and H1299 cells takes place via the non-phagocytic pathway (CME, CVME, or macropinocytosis) predominantly.¹¹⁵ These mechanisms affect their intracellular trafficking, bioavailability, and cytotoxic effects.¹¹⁶ The four main endocytic mechanisms covered in this article are clathrin-mediated endocytosis (CME), caveolin-mediated endocytosis (CVME), phagocytosis, and micropinocytosis. Macrophages present in the pulmonary microenvironment are responsible for the uptake of AgNPs via phagocytosis. This elucidates the specificity of endocytic processes in terms of cell types and highlights the broader biological importance of AgNP movement in the lung tumor microenvironment, where the cancerous and immune cells interact.¹¹⁷

5.1.1. Phagocytosis. Phagocytosis is a cellular process whereby a cell surrounds large particles with a membrane and then ingests and actively absorbs them, as depicted in Fig. 7a. One of the major features of the process, phagocytosis, is the internal vesicles, or phagosomes, which are typically approximately 250 nm in diameter.^118,119 Phagocytosis is done by special phagocytic cells, such as dendritic cells, macrophages, monocytes, neutrophils, and B lymphocytes. Opsonization and adherence of immunoglobulins, e.g. antibodies (Abs), as well as complement proteins and other serum proteins, e.g. laminin and fibronectin, to the surface of NPs facilitate the elimination of the NPs through the complement system, scavenger, and Fc receptors, prompting a signaling cascade, actin assembly, cell surface extensions and engulfment and internalization.¹²⁰ The major receptors that contribute to the process of phagocytosis include the IgG Fc receptor family (includes FcgRI, FcgRIIA and FcgRIIIA), complement receptors (include CR1–CR4) and the a5b1 integrin.¹²¹ Alveolar macrophages and tumor-associated macrophages (TAMs) can internalize AgNPs in lung tissue through the Fc and complement receptor. Such macrophages can be used as a sink, which can cause competition between them and cancer cells in the uptake of NP, or they can be used to complement the redistribution of the NPs once ingested.¹²² Surface modifications, including Ab-conjugation or the adsorption of opsonins, can be used to enhance macrophage targeting, which can be beneficial to immunotherapy but may also impair the delivery of cancer-specific NPs.¹²³

Fig. 7 Schematic of the different cellular pathways of AgNPs uptake between the extracellular and intracellular spaces. The entry into cells can occur by (e) passive diffusion or by endocytic processes, including (d) caveolin-mediated endocytosis, (c) clathrin-mediated endocytosis, (b) macropinocytosis and (a) phagocytosis. After internalization, the NPs are transported via early and late endosomes (pH 6.5–5) and lysosomes, and they eventually interact with intracellular organelles, such as the ER and Golgi apparatus.

5.1.2. Receptor-mediated endocytosis (RME). RME is divided into several categories, including CME, CVME, and clathrin-/caveolin-independent endocytosis, which represent the major pathways. The most well-studied mechanism of transporting substances into eukaryotic cells is CME.¹²⁴ It is a complex process that involves intercellular signal transduction, membrane recycling and the uptake of nutrients. The vesicle formation relies on a diverse set of proteins and interactions between stimuli and their respective receptors.^125,126 The encapsulation of these vesicles by clathrin results in the creation of clathrin-coated vesicles, as shown in Fig. 7c. The dimensions of clathrin-coated vesicles vary according to the type of cell, generally falling within the range of 70–150 nm.¹²⁷ The process of vesicle release from the plasma membrane is controlled by GTPase and dynamin.¹²⁵ Following the release of the vesicles, clathrin undergoes degradation facilitated by auxilin- and heat shock cognate 70-dependent proteins.¹²⁷ Some of the components are sent to early endosomes, while some are brought back to the surface of the plasma membrane. Additionally, vesicles may reach later-stage endosomes before moving on to lysosomes and multivesicular bodies (MVBs), as well as other cellular compartments. The majority of receptor-mediated nanoparticle uptake by cells takes place via CME. In the A549 and H1299 cells, transferrin- or folate-conjugated AgNPs utilize clathrin-coated pits to gain entry through receptor-mediated endocytosis. Inhibiting transferrin receptors (TfR) or pre-treating the cells with chlorpromazine, a clathrin-assembly inhibitor, significantly diminishes AgNP uptake, thereby confirming the dependence on clathrin-mediated endocytosis.¹²⁸

CVME is recognized as the second most thoroughly studied endocytic pathway, playing a vital role in intracellular transport and mechanosensing within cells. This process is initiated by the ligand-receptor binding, which generates flask-shaped invaginations called caveolae, which measure 60–80 nm in diameter within the plasma membrane,¹²⁹ as displayed in Fig. 7d. A variety of proteins are recruited in the endocytic pathway, including caveolin-1, which interacts with cholesterol in lipid rafts; importantly, caveolin-1 remains associated with vesicles even after internalization, in contrast to CME.¹³⁰ Vesicle formation is influenced by kinases and phosphatases, such as Src tyrosine kinase and the serine/threonine protein phosphatases PP1 and PP2A.¹³¹ Similar to CME, the protein dynamin is crucial for the detachment of vesicles from the cell membrane, resulting in the formation of caveolin vesicles that can merge with other caveolin vesicles to create multivesicular structures, which then fuse with early endosomes.¹³² Depending on the type of cell, these vesicles may subsequently travel to the SER or the Golgi transport network.¹³³ A549 cells exhibit elevated levels of caveolin-1 and internalize albumin-coated or cholesterol-functionalized AgNPs via caveolae-dependent endocytosis.¹³⁴ Therefore, caveolin-mediated uptake offers benefits for drug-loaded NPs intended for the treatment of lung adenocarcinoma.

5.1.3. Macropinocytosis. Macropinocytosis is a dynamic process through which cells actively engulf significant amounts of extracellular fluid, resulting in the biogenesis of large vesicles termed as macropinosomes, with diameters ranging from 0.5 to 10 µm¹³⁵ (Fig. 7b). This mechanism is commonly employed by macrophages to engulf apoptotic cell debris, other cells, and bacteria. Unlike phagocytosis and RME, macropinocytosis is not strictly governed by specific receptors or other molecular signals. Research has shown that the activation of tyrosine kinase receptors is linked to the induction of macropinosomes during this process.¹³⁶ After NMs are internalized via macropinocytosis, the pH within macropinosomes gradually decreases. As a result, the acidified macropinosomes can either be fused with the late endosomes, interact with the lysosomes or recycle the contents to the cell membrane.¹¹⁶ Also, there are clathrin or caveolin-independent endocytosis (CIE) pathways, which encompass the abovementioned processes. It has been indicated that CIE is involved in the process of regulating several processes, which include cell polarization, intercellular signal transduction, cell growth and repair of the plasma membrane.¹³⁷ The synthesis of raft proteins is dependent on the formation of vesicles in the endocytosis process that is controlled by RhoA and CDC42.¹³⁸ The synthesis of raft proteins is necessary in the endocytosis process, involving various proteins like Arf-6, Rho-A (associated with the IL2Rb-dependent pathway), flotillin, and CDC42.¹²⁷ RhoA acts via a dynamin-dependent mechanism and is implicated in the uptake of proteins in immune cells and fibroblasts, such as the interleukin-2 receptor (IL-2R-b).^116,139 However, it is not investigated further because few studies have explored its role in the uptake of NMs. In contrast, CDC42 is involved in a dynamin-independent route that promotes the internalization of CtxB and VacA.¹¹⁶ The increase in macropinocytosis within metabolically active LC cells, namely A549 cells with KRAS mutations, has a significant impact on cancer biology and nanomedicine in general. The mechanism enables the non-specific absorption of large amounts of extracellular fluid, which may be used to deliver drugs better with the help of special NPs.¹⁴⁰

5.2. Passive mechanism

Direct cellular entry occurs when NPs can enter the cell plasma membrane via different biochemical or physical events, and they include the following: (i) direct translocation, whereby NPs disrupt the plasma membrane to enter without being trapped in endosomes or using energy-dependent transport, as demonstrated in (Fig. 7e); (ii) lipid fusion, in which NPs covered with lipid bilayers merge with the plasma membrane, followed by the direct translocation of their cargo into the cytoplasm; (iii) the method of producing NPs by internalization through electroporation or making holes in the membrane with the help of electrical pulses; (iv) microinjection, which entails the use of special microinjectors to bring NPs to the cytoplasm.¹⁴¹ Passive entry mechanisms such as membrane fusion, translocation, or electroporation are not commonly seen in physiological contexts, but they can be applied to deliver specifically designed NPs to the pulmonary cytosomal space. For passive crossing, AgNPs smaller than 10 nm have the capacity to cross lipid bilayers passively due to their increased surface energy and possible membrane-disrupting properties. This property explains their concentration in cells even under conditions when active endocytosis is not taking place.¹⁴²

The EPR effect is a vital targeting mechanism for AgNP delivery in the treatment of solid tumors, including LC.¹⁴¹ NSCLC tends to have aggressive vascular responses, abnormal angiogenesis, and increased metabolic demand conditions, which favor the use of the EPR effect. The fast-growing tumor mass in LC contributes to the formation of dysfunctional blood vessels that have enlarged endothelial gaps, insufficient pericyte cover and disproportionate vessel density. The result of these structural abnormalities is that the vascular permeability becomes enhanced, enabling AgNPs, which are typically between 40 and 400 nm, to passively leave the bloodstream into the tumor interstitium.¹⁴³ In parallel, the dysfunctional lymphatic drainage observed in lung tumors prevents the elimination of these NPs and, thus, increases their retention in the Tumor Microenvironment (TME). AgNPs have unique physicochemical properties that enhance their circulation, tumor localisation and cytotoxicity. PEGylation is one of the possible modifications that increase the half-life of NPs by preventing their elimination by the mononuclear phagocyte system (MPS) and the immune system. AgNPs respond to the acidic, hypoxic, and redox-imbalanced conditions inside the lung tumor tissue, after retention into the tissue, releasing Ag⁺ ions and consequently forming ROS.¹⁴⁴

The cellular uptake of AgNPs in LC cells occurs predominantly through energy-dependent endocytic mechanisms, including clathrin-mediated endocytosis, caveolin-mediated endocytosis, macropinocytosis, and phagocytosis. The cellular interactions and intracellular localization also vary depending on shape, and shape changes affect ROS generation and apoptotic responses. Also, surface coating (e.g., PVP or citrate) will have a profound influence on the stability of AgNPs and the dissolution of the ions. The steady leakage of Ag⁺ ions in A549 and H1299 cells is a key factor influencing cytotoxicity as these ions react with thiol-containing proteins to disrupt antioxidant defenses and contribute to increased oxidative stress. The effects are also controlled by the particle size, where smaller AgNPs exhibit a higher cellular uptake and higher ion release, thus enhancing the level of mitochondrial dysfunction and DNA damage. A combination of these AgNP-specific properties generates different mechanistic results in A549/H1299 models,¹⁴⁵ which are not so clear in non-ion-releasing or less redox-active NMs. Despite these mechanistic insights, most findings originate from in vitro cellular studies, and further investigation is necessary to understand how these pathways operate within the complex tumor microenvironment in vivo.

6. Deciphering the cytotoxic pathways triggered by AgNPs in LC cells

HeLa and A549 cells showed the release of intracellular Ag⁺ ions following the internalization of NPs, suggesting that the acidic environment of lysosomes promotes particle breakdown and establishes a causal association between ion release and eventual cell death.¹⁴⁶ In vitro studies of the anti-cancer effects of the NPs against human LC¹⁴⁷ have shown that they cause toxicity in cancer cells by disrupting the cell cycle, reducing ROS production, impairing mitochondrial function, releasing lactate dehydrogenase (LDH), and activating apoptotic genes like Bax, as well as causing the formation of apoptotic bodies, DNA damage, micronuclei, and chromosomal abnormalities (Fig. 8). Other works have clarified the relations between AgNPs and the immune system, which suggest that AgNPs can cause inflammation in the target cells. The stimulation of inflammatory response occurs due to the synthesis of these NPs by the macrophages, which release TNF-a, inflammatory cytokines, and interleukins (IL-6) upon activation. The effectiveness and efficiency of AgNPs in the production of ROS depend on their size, with smaller NPs being more effective. However, as a result of biological processes, the anti-proliferative effect and anti-angiogenic effect of AgNPs have also been identified.¹⁴⁸

Fig. 8 Mechanism of action of AgNPs in lung cancer cells.

6.1. Induction of oxidative stress and ROS generation

AgNPs have been shown to be effective in the treatment of cancer, particularly LC, by triggering oxidative stress through the generation of ROS. This begins with the cellular uptake of AgNPs (Fig. 7) via direct or different endocytic mechanisms. These pathways allow the entry of AgNPs into the cell and their localization in organelles like the lysosome, ER and especially mitochondria, which is the most important in the production of ROS (Fig. 8).¹⁴⁹ AgNPs cause the depolarization of the mitochondrial membrane and the suppression of the electron transport chain within the mitochondria. This imbalance results in the leakage of electrons, whereby the superoxide anions (O₂⁻), subsequently, are converted into hydrogen peroxide (H₂O₂) and hydroxyl radicals (OH) by the mitochondrial antioxidant system. The overproduction of these ROS leads to mitochondrial impairment and the destruction of cellular constituents, such as lipids, proteins, and DNA, which adds to oxidative stress.¹⁵⁰ In addition, AgNPs may be localized to lysosomes, damaging the lysosomal membrane and leading to an enzyme and iron leakage. The accumulation of ROS in the cytoplasm and organelles leads to cell damage by oxidative stress, the denaturation of proteins, and the damage to DNA.¹⁵¹ The peroxidation of lipid molecules by ROS breaks down cell membranes, whereas the oxidation of proteins by ROS can cause enzyme loss of activity and structural damage.¹⁵² The ROS-mediated DNA damage may also cause mutations, breakage of chromosomes, and the initiation of DNA repair. AgNPs increase oxidative stress in LC cells, which already have high concentrations of ROS, pushing the cells to a threshold that induces apoptosis. AgNPs also impair cellular antioxidant defenses, along with ROS generation. The decrease in the antioxidant content (such as glutathione [GSH]) and the inhibition of enzymes (such as superoxide dismutase [SOD] and catalase) reduce the cell's ability to counteract the ROS and, thus, enhance oxidative stress in LC cells.¹⁵³ This triggers signaling pathways, including the MAPK and NF-κB pathways, which regulate cell viability, inflammation, and cell death. The excessive ROS produced by AgNPs in LC cells activates intrinsic and extrinsic apoptotic pathways. In the intrinsic pathway, mitochondrial dysfunction induced by ROS causes cytochrome c release, which subsequently activates caspase-9 and caspase-3, ultimately resulting in cell death (Fig. 8). In a study on LC cells, AgNPs ranging from 10–50 nm effectively suppressed tumor growth and induced cell death by increasing ROS production, activating mitochondrial signaling cascades, enhancing the activity of apoptotic enzymes such as caspase-3 and caspase-9, inducing morphological alterations including chromatin condensation, and inhibiting key carcinogenic processes.¹⁵⁴ Conversely, in the extrinsic pathway, apoptosis is mediated through ROS-dependent upregulation of death receptor signaling. AgNPs stimulate the formation of ROS by damaging mitochondria, destabilizing the lysosome, and disrupting cellular antioxidant response.¹⁵⁵ This oxidative stress causes cell damage and triggers apoptotic activities in LC cells. AgNPs show selective toxicity towards cancer cells by exploiting their high quantity of ROS levels and inherent sensitivity to oxidative stress. Moreover, the inflammatory and metastatic process modification highlights the therapeutic potential of AgNPs in the treatment of LC. The ability to trigger ROS and disrupt the homeostasis of cancer cells makes AgNPs a strong candidate for targeted treatment, a novel approach to treating LC.¹⁵⁶

6.2. AgNP-induced mitochondrial dysfunction

The recent study into the cytotoxic effects of AgNPs on LC cells produced valuable results regarding the specific biochemical mechanisms through which these particles exert their impact.¹⁵⁷ The ions in question play a part in the appearance of ROS that disrupt mitochondrial activity and cause cell damage. Mitochondria are essential for the production of energy, regulation of cellular metabolism, and maintenance of cellular integrity.^148,158 However, when subjected to AgNPs, mitochondrial dysfunction ensues, whereby a time- and dose-responsive increase in mitochondrial ROS and the oxidation of cellular proteins occur (Fig. 8).¹⁵⁹ This mitochondrial perturbation is correlated with the shifts in cell cycle progression, including the G2-phase arrest in sensitive cell lines, such as A549 and Calu-1.^160,161 It is noteworthy that the NCI-H358 cells, which are more resistant to AgNPs, did not show significant mitochondrial ROS and protein oxidation, despite a decrease in cell proliferation under the combination of AgNPs and ionizing radiation. An in-depth examination of mitochondrial respiration revealed that the AgNP exposure caused a reduced ATP level in these cells, particularly in the AgNP-sensitive lines.¹⁶² There was also a rise in mitochondrial respiration that may have been compensatory in nature. Nevertheless, this did not lead to profound alterations in the mitochondrial respiration parameters in the different cell lines. This depleted ATP, together with mitochondrial dysfunction, led to a significant drop in cell viability, especially in the Calu-1 cell line, which underwent an almost complete loss of ATP after prolonged exposure to AgNPs.¹⁶³ Factors such as mitochondrial mass and redox condition may be the cause of this susceptibility of different LC cell lines to AgNPs. In particular, Calu-1 cells that are sensitive to AgNPs (obtained by means of the lung pleura) exhibited more mitochondrial dysfunction as compared to NCI-H358 cells (obtained by means of the bronchoalveolar tissue). This implies that the anatomical source of lung cells might have a role to play in their sensitivity to AgNPs,^164,165 and similar in vivo studies have shown that exposure to AgNPs causes pleural inflammation and fibrosis in animals. Overall, it can be concluded that the mitochondrial dysfunction and ROS generation caused by AgNPs in LC cells are essential factors influencing cell death, and the cellular response varies across cell types. These findings indicate the need to understand the molecular pathways of AgNP-induced toxicity, which would guide future clinical treatment and risk management regarding the use of AgNPs.

6.3. DNA damage and cell-cycle arrest

Prior research has examined the cell cycle arrest and cytotoxic effects caused by AgNPs.^166–168 As the duration of exposure increases, the impact of AgNPs on the cell cycle and apoptosis increases, thereby exacerbating both cellular and genomic toxicity. Typically, cell cycle checkpoints, such as G2/M, are activated in response to DNA damage, preventing cells from progressing into mitosis (M phase). An elevation in G2/M cell-cycle arrest signifies that a greater proportion of cells are stalled in the G2 phase to facilitate DNA repair. Cells that have been successfully repaired can proceed to mitosis; however, those that sustain irreparable damage experience an irreversible G2/M cell-cycle arrest, followed by apoptosis.¹⁶⁹ Au@Ag nanorods (NRs) can significantly keep HepaRG cells in the G2/M phase, promote late-stage apoptosis, and increase p53 and p21 levels, which are key regulators of the cell cycle.¹⁷⁰ Given that p53 can also trigger apoptosis if DNA repair fails, p21 may play an indirect role in apoptosis through cell-cycle arrest via a mechanism dependent on p53, achieved by downregulating the nuclear protein ICBP90, which is involved in DNA replication and cell-cycle control.¹⁷¹ Additionally, apoptosis and G2/M arrest linked to the p53/p21 pathway have been documented in HepG2 cells treated with garlic extracts.¹⁷² Consequently, it can be deduced that oxidative stress-related damage to DNA and chromosomes may increase the expression of p53 and p21, leading to cell-cycle arrest. Extended exposure to Au@Ag NRs during the replication of DNA and chromosomes could further augment genotoxic effects and apoptosis.¹⁷⁰

6.4. Autophagic cell death and autophagy

Certain research indicates that AgNPs serve as inducers of autophagy with a protective effect. To delve deeper into this hypothesis, one could employ the well-known autophagy inhibitor, chloroquine, or assess the effects of AgNPs in hypoxic environments, where it is believed that autophagy is induced (Fig. 8).^173–175 Numerous studies have shown that autophagy and apoptosis interact, and their simultaneous activation enhances their antitumor effects.¹⁷⁶ AMPK is a crucial sensor in cellular metabolism regulation. Changes in the ATP to AMP ratio boost its activity, leading to Autophagy Activating Kinase 1 (ULK1) phosphorylation, vital for autophagy initiation; mTOR is the main antagonist of ULK1 and plays a critical role in the proliferation and survival mechanism of cancerous cells.¹⁷⁷ In their 2020 research, Chen et al.¹⁷⁸ investigated the regulatory effects of PVP-coated AgNPs on autophagy within the ‘PC-3’ human prostate cancer cells at non-toxic concentrations. Their flow cytometry analysis showed that AgNP treatment did not induce apoptosis; however, there was a substantial elevation in all autophagic markers. This was coupled with lysosomal impairment, evidenced by reductions in the lysosome count and the protease activity, with a substantial decrease in cathepsin D expression, eventually resulting in the blockage of autophagic flux. Hypoxia, which is characterized by increased concentrations of HIF-1, and an energy deficit caused by the activity of NPs promoted the activation of AMPK and inhibited the expression and phosphorylation of mTOR. Due to this cascade of events, ACC1 (acetyl-CoA carboxylase 1), being an AMPK target, was activated, and S6K, a mTOR target necessary as a protein synthesis factor, cell growth factor, proliferation factor, and survival factor, was inhibited. Protein LC3-I/II is identified as one of the major autophagy markers, and the rise of its expression implies active autophagic activity. In addition, p62/SQSTM1 (sequestosome 1) is a key autophagy receptor that attaches cytoplasmic components for degradation.¹⁷⁹ The significant increase in p62 in the tumor cells after treatment implies that the autophagic flux is probably disrupted. In that regard, AgNPs are found to induce autophagy as the defense response, implying that the inhibition of this route is likely to enhance the antiproliferative effects of AgNPs. Autophagy plays a dual role in AgNP-induced responses in LC models, acting as either a cytoprotective or cytotoxic mechanism depending on the exposure dose and duration. The AgNP-induced oxidative stress and mitochondrial damages in the A549 and H1299 cells commonly trigger autophagy as a mechanism of adaptive cell survival, enabling the clearance of damaged organelles and the minimization of cellular damage.¹⁸⁰ Protective autophagy is capable of inhibiting apoptotic cell death, consequently diminishing the therapeutic activity of AgNPs, especially at low or sublethal levels. Conversely, during elevated exposure or prolonged stress, overload or dysregulated autophagy can result in a cytotoxic outcome, leading to autophagic cell death. Thus, the balance between protective and destructive autophagy is considered a decisive factor influencing AgNP therapeutic effects, and protective autophagy represents a barrier that could limit the therapeutic effect of AgNPs.

6.5. AgNPs and MAPK pathway

Numerous studies have looked at how NPs affect the regulation of key components in different signaling pathways, highlighting their capacity to affect cellular processes linked to inflammation, stress response, and programmed cell death.^181,182 AgNP synthesis with sinigrin has been studied in relation to the regulation of critical components within different signaling pathways to highlight the pro-apoptotic effect associated with cytochrome c release; activation of caspases (-3, -6, and -8); and an increase in levels of p21, p53, and pro-apoptotic proteins, such as Bid, Bax, and Bak.¹⁸³ The authors suggest that apoptosis was induced by stress kinases p38 and JNK, which were activated by stressors, including cytokines, osmotic pressure and radiation. Both the kinases and NF-kB were upregulated in HeLa cells that were exposed to AgNPs, despite the combination with camptothecin. On the other hand, the activity of the Akt and the components of the Raf-MER-Erk signaling pathway were found to be reduced, which probably reduced the viability of tumor cells and promoted apoptosis via the downregulation of growth factor-related kinases.¹⁸⁴ Liu et al.¹⁸⁵ found comparable alterations in the phosphorylation levels of p38, JNK and Erk1/2 in U251 cells (human glioma). The introduction of the GSH antioxidant diminished the activation of these kinases, suggesting that the MAPK signaling pathways are activated through a ROS-mediated mechanism. Enhanced phosphorylation of Erk1/2 has also been reported to correlate with increased cell survival and proliferation, but Erk-mediated pathways have been reported to cause apoptosis.¹⁸⁶ These findings align with previous findings, demonstrating that AgNP treatment significantly downregulates Akt and Erk1/2 expression in human bladder cancer (T24) cells while promoting apoptosis through Erk-mediated signaling pathways.¹⁸⁷ Additionally, ROS triggered the p38 stress kinase in A549 cells, which in turn activated caspase-3;¹⁸⁸ likewise, in several tumor cell lines, such as MDA-MB-231, MCF-7, U251, and MO59K, there was an apparent rise in JNK phosphorylation, along with the increased expression of its direct downstream target, c-Jun. The genotoxic effects of AgNPs have been demonstrated by the increased accumulation of γ-H2AX, a known marker of DNA damage, as well as damage to telomeres. Following AgNP treatment, telomere alterations were noted, which coincided with a decrease in intracellular TRF2 levels, a crucial protector of telomeres, and a downregulation of hTERT, the enzyme telomerase's catalytic component.¹⁸⁹ The phosphorylation of DNA-PKcs, crucial for repairing DNA double-strand breaks, positively influences the expression of JNK. Inhibiting DNA-PKcs resulted in reduced phosphorylation and expression of DNA-PKcs, as well as decreased levels of both phosphorylated and total JNK, which ultimately affected tumor cell survival. These findings indicate that blocking DNA repair pathways, like those involving DNA-PKcs, may amplify the antiproliferative and cytotoxic effects of AgNPs on tumor cells.¹⁹⁰

Mechanistic studies collectively demonstrate that AgNP-induced cytotoxicity in LC cells primarily arises from ROS generation, mitochondrial dysfunction, DNA damage, and activation of apoptotic signaling pathways, such as MAPK and p53-mediated responses. This exploits the inherent vulnerability of cancer cells to oxidative stress, thereby promoting selective cytotoxic effects relative to normal cells. Particle size, surface chemistry, and intracellular ion release play critical roles in modulating these biological responses. The cytotoxic effects of AgNPs in LC models occur via some distinct mechanisms. Through AgNPs, as opposed to other NMs, the release of Ag⁺ ions is continuous and attaches to the thiol (-SH) groups of protein,¹⁹¹ disrupting the antioxidant systems of glutathione and thioredoxin and enhancing oxidative stress.¹⁴⁵ Also, they have a redox-active surface that promotes the generation of ROS, which cause mitochondrial dysfunction, such as membrane potential loss and decreased ATP generation. The AgNPs also tend to accumulate in the lysosomes, resulting in their destabilization, leading to subsequent cell death pathways. All of these, i.e., the constant Ag⁺ release, thiol reactivity and the increased redox activity, characterize the unique cytotoxic signature of AgNPs in LC models. While numerous studies confirm these mechanisms in cultured LC cell lines, in vivo validation of these pathways remains limited, emphasizing the need for mechanistic studies in physiologically relevant tumor models. Despite the excellent potential of AgNPs as anticancer agents in the context of LC models, it has not been easy to translate the lab findings into actual clinical practices. With lower doses, their efficacy is likely to decrease, whereas with high doses, they may damage normal cells. The results obtained with A549 and BEAS-2B cells¹⁹² indicate that AgNPs are not necessarily selective to tumors. Rather, they tend to cause a general oxidative stress and the dysfunction of lysosomes in cancerous and normal cells,¹⁹³ and this prompts concerns regarding unwanted side effects.

7. Silver-mediated combination therapies: enhancing anticancer efficacy through synergistic approaches

NM-based cancer therapy, comprising the combination of NMs with chemotherapeutic drugs, exhibits significantly improved therapeutic efficacy against cancer. In conventional chemotherapy, combination therapy appears to be a standard route to bypass cross-resistance and produce a synergistic therapeutic effect without noticeably increasing adverse toxicities. Among metallic NPs, like Zn, Au, Ag, Ti, Cu, and Mg, AgNPs are widely known for their biomedical applications, attributed to their antibacterial, anti-cancer, antiviral, anti-inflammatory and antifungal activities. However, AgNPs alone exhibit little antibacterial or anticancer effect compared to combination treatments. To avoid undesirable side effects, AgNPs must be taken in combination with an anticancer medication. Also, studies revealed that AgNPs have a well-established ability to improve other NPs’ activity when used as a dopant.¹⁹⁴ Table 2 summarizes the studies of combinations of various drugs/NPs with Ag for treating LC effectively.

Table 2 Summary of various Ag-based multifunctional nanocomposites, along with their physicochemical properties, drug-loading efficiency, and cytotoxic activity against LC and cell lines

Nanocomposite	Chemotherapeutic agents	Size (nm)	% Drug loading		Lung cancer cell line	IC50 value (µg mL^−1)/nM	Toxicity to normal cell line IC50 value (µg mL^−1)	Treatment exposure time (hours)	Ref.
Ag-MTX	Methotrexate	13		28%, 31% and 40%	A549	23	—	48	195
Ag-PTX	Paclitaxel	24.36–58.77		—	A549	8.58 ± 0.34	WI-38 (56.07 ± 3.54)	48	196
Ag-Car	Carboplatin	30–40		—	A549	3.58	WI-38 (153.63 ± 3.56)	24	197
Ag-shikonin	Phytochemical naphthoquinone	20		—	A549	2.4 ± 0.11	—	24	198
DsAgN-5FU	5-Fluorouracil	8.32		25.9% ± 3.5%	A549	5	—	48	199
AgNP-RTX	Raltitrexed	20.4 ± 0.4		—	A549	1000 nM	—	72	200
ZnO@Ag	—	—		—	A549	—	—	48	201
ZnO@PDA@Ag	—	10–30		—	H1299	42.42 ± 4	—	48	202
CuO@Ag	—	—		—	A549	15	—	24	203
Fe3O4@SiO2@PDA@Ag	—	10–30		—	H1299	21.52	—	48	204
Ag/Fe3O4	—	20–40		—	NCI-H661	183	HUVECs	48	205
					NCI-H1975	176
					NCI-H1573	169
					NCI-H1563	125
In2O3@Ag	—	25.10		—	A549	18.01	IMR90 (>100)	24	206
Ag–CuO	—	—		—	A549	2.8 ± 0.05	—	24	207
Fe3O4@Alg–Ag	—	20–40		—	NCI-H1975	194	HUVECs	48	208
					NCI-H1573	255
					NCI-H1299	427
AgZnO	—	11		—	A549	15	BEAS-2B (>90)	24	209

---

7.1. Silver combination with anti-LC drugs

AgNPs have been widely explored as carriers for small-molecule chemotherapeutics, where their high surface area and tunable surface chemistry enable efficient drug loading and controlled delivery. In such systems, AgNPs not only act as delivery platforms but also contribute to enhanced cytotoxicity through ROS-mediated mechanisms.

Methotrexate (MTX), a chemotherapeutic folic acid analog, is characterized by its short duration in the bloodstream and high cellular efflux rate, causing many restrictions on its clinical applications. A combination drug of Ag and MTX was synthesized by Rozalen et al., and its anticancer activity against A549 cell lines was tested. The results demonstrate that the conjugation of MTX to AgNPs enhanced its therapeutic effect and thereby lowered the MTX effective dosages needed. However, there was no noticeable reduction in cell viability following treatment with AgNPs alone. Also, an in vivo zebrafish assay indicated that AgNP-MTX did not induce significant toxicity or malformations, suggesting a favorable safety profile for further therapeutic applications.¹⁹⁵ Paclitaxel (PTX) is one of the most potent anti-cancer drugs; however, its clinical applications are limited by poor aqueous solubility. Thus, a combination of AgNPs and PTX was prepared, exhibiting significantly enhanced anticancer activity compared to paclitaxel alone across various cancer cell lines, particularly showing an improved selective cytotoxic effect in A549 LC cells. Additionally, the study demonstrated that AgNP-PTX induced DNA fragmentation, leading to increased apoptosis in cancer cells compared to treatment with paclitaxel alone. Further, in the WI-38 healthy cells, low toxicity was observed, which indicates that AgNP-PTX can effectively minimize the side effects commonly associated with cancer therapies, making it a safer alternative for treatment.¹⁹⁶ To reduce the drug-related side effects of Carboplatin (Car), a study utilized AgNPs as a carrier for the drug. The synthesized AgNPs and carboplatin-loaded AgNPs (AgNPs-Car) show significant promise as candidates for treating human lung carcinoma. Interestingly, the combination induced DNA fragmentation and eventually increased the apoptosis of cells due to the release of Ag⁺ ions and the formation of radical species, which disrupt critical cellular mechanisms.¹⁹⁷ The synergetic effect of shikonin, a phytochemical naphthoquinone isolated from the roots of the Chinese herbs ‘Lithospermum erythrorhizon’ and AgNPs in A549 cells was studied, and they significantly inhibited cell viability and proliferation in A549 cells more effectively than individual components. In this study, Shikonin functioned as a stabilizing and reducing agent in AgNP synthesis, which may contribute to their anticancer properties. AgNPs' ability to liberate Ag⁺ is facilitated by the acidic surroundings of cancerous cells, which intensifies their lethal effects on cancer cells in particular. Also, an in vivo study conducted on normal mice indicated that shikonin-AgNPs have a potential lung-targeting ability.¹⁹⁸ A novel multicomponent system was created, which uses Generation 5 (G5) PAMAM dendrimers to deliver both AgNPs and the hydrophobic anticancer drug 5-fluorouracil (5-FU) to cancer cells. The combination of 5-FU and dendrimer-stabilized silver nanoparticles (DsAg NPs) exhibited a synergistic effect in inhibiting the growth of A549, suggesting that this nanocomposite can enhance the anticancer effects compared to using 5-FU alone.¹⁹⁹ Another study demonstrated that covalently attaching Raltitrexed (RTX) to AgNPs produces a synergistic therapeutic effect, where the antifolate activity of the drug and the intrinsic ROS-generating properties of AgNPs jointly enhance cytotoxicity. This direct drug-NP conjugation achieved substantially better anticancer efficacy than the free drug alone.²⁰⁰

Overall, these studies frequently report enhanced cytotoxicity and apoptosis in LC cell lines. While these findings suggest potential synergistic effects through mechanisms such as ROS amplification and improved intracellular drug delivery, most investigations remain restricted to single-cell-line models and short-term in vitro assays. Robust pharmacokinetic analysis, reproducibility across multiple tumor models, and comprehensive toxicity assessments are still largely absent. Consequently, the current evidence supports the potential of AgNP-based drug combinations but remains insufficient to establish clear translational advantages. Despite enhanced activity, the contribution of Ag versus that of the host material is often not systematically distinguished, and toxicity toward normal cells remains underexplored.

7.2. Silver-doped metal oxide combination action on LC treatment

The enhancement and synergistic effects resulting from Ag doping in other NPs have been extensively investigated by various researchers. The Ag-doped ZnO system has been the most extensively studied due to its inherent biocompatibility and superior photocatalytic behavior. Studies by A. Ullah et al.²⁰¹ showed that Ag doping significantly influences the structural and optical properties of ZnO NMs. Low-level doping (0.3 wt%) significantly enhanced ZnO's anticancer activity against A459 cells, achieving 72.86% inhibition. This improvement can be attributed to the increased production of ROS via charge separation, the electrostatic attraction between Ag⁺ and Zn²⁺ ions and negatively charged cancer cell membranes, and the improved crystallinity that facilitates electron-transfer processes.

At high doping concentrations (0.6 wt%), the activity decreased due to structural distortion, indicating the need for an optimal Ag concentration for synergy.²⁰¹ A similar work reported the successful synthesis of a novel ZnO@PDA@Ag nanocomposite, where Ag-doped polydopamine (PDA)-coated ZnO produced strong cytotoxicity against H1299 cells (IC₅₀ = 42.42 ± 4 µg mL⁻¹) with high biocompatibility, highlighting the combined benefits of Ag doping and PDA-mediated stabilization.²⁰² In a CuO system synthesized via green routes, Ag doping amplified anticancer efficiency by doubling the cytotoxic effect compared to undoped CuO. The 20% Ag-doped CuO NPs triggered 50% cell death at only 15 µg mL⁻¹, attributed primarily to ROS overproduction and the disruption of mitochondrial function. The synergy arises because Ag enhances electron transport, while CuO contributes intrinsic oxidative stress, forming a potent dual-metal oxidative assault on cancer cells.²⁰³

7.3. Ag-doped magnetic and hybrid combination action on LC treatment

Ag doping also significantly enhances the therapeutic value of magnetic NPs, like Fe₃O₄. The Fe₃O₄@SiO₂@PDA@Ag nanocomposite induced pronounced apoptosis in H1299 cells (IC₅₀ = 21.52 µg mL⁻¹), demonstrating how Ag's surface reactivity complements Fe₃O₄ magnetic guidance while maintaining biocompatibility (Fig. 9a).²⁰⁴ Similarly, the Ag–Fe₃O₄ nanocomposite prepared using Mentha extract as a reducing and stabilizing agent displayed strong cytotoxic effects against multiple LC cell lines, NCI-H661, NCI-H1975, NCI-H1573, and NCIH1563 (IC₅₀ values: 183, 176, 169, and 125 µg mL⁻¹, respectively).²⁰⁵ The presence of Ag protected Fe₃O₄ from oxidation and provided additional ROS-mediating sites, contributing to selective cancer targeting.¹⁷⁰ The photodeposition of Ag-doped In₂O₃ NPs achieved a pronounced dose–response increase in anticancer performance. The addition of Ag from 2% to 6% resulted in a drastic decrease in the values of IC₅₀ against A549 cells to 75.81 and 18.01 µg mL⁻¹, respectively, in pure In₂O₃ and 6% Ag doped In₂O₃. The enhancement is due to an increased crystallinity, better electron–hole separation and more oxidative radicals. The overall impact of these changes resulted in the oxidative damage of cancer cells, with no effect observed on the biocompatibility of good to normal IMR90 fibroblasts.²⁰⁶ Bimetallic and hybrid systems also benefit greatly from Ag incorporation. The hybrid silver–copper nanocomposite (Ag–CuO NCs) synthesized with Ocimum americanum L. extract exhibited potent antiproliferative activity against A549 cells (IC₅₀ = 2.8 ± 0.05 µg mL⁻¹), inducing apoptosis and cell-cycle arrest at the G0/G1 phase (Fig. 9c).²⁰⁷ Similarly, alginate-modified Fe₃O₄ decorated with Ag (Fig. 9b) displayed strong cytotoxic effects against NCI-H1975, NCI-H1563, and NCI-H1299 LC cells while sparing normal HUVECs, indicating selective toxicity aided by Ag's interaction with malignant cell membranes.²⁰⁸ Bimetallic AgZnO NPs formed using Salvia officinalis extract further confirmed the synergetic action. The combination of Ag and ZnO produced significantly better anticancer activity than AgNPs alone, while the plant-derived capping provided biocompatibility with BEAS-2B normal cells. The bimetallic structure enhanced apoptosis and inhibited the migration of A549 cells.²⁰⁹

Fig. 9 Synthesis of Ag-doped nanocomposites: (a) Fe₃O₄@SiO₂@PDA@Ag nanocomposite, reproduced from ref. 204, with permission from Taylor and Francis, copyright 2024; (b) Fe₃O₄@Alg–Ag nanocomposite, reproduced from ref. 208, with permission from Elsevier, copyright 2022; and (c) Ag–CuO nanocomposite, reproduced from ref. 207, with permission from Elsevier, copyright 2023.

The above-discussed studies demonstrated the enhanced anticancer activity of AgNPs against LC cells through synergistic mechanisms, such as increased ROS generation and oxidative stress. While several studies report the improved cytotoxicity and selectivity of AgNPs compared with single-component NPs, most of the results are derived from in vitro models and vary considerably based on differences in synthesis methods, NP composition, and experimental conditions. Consequently, although these hybrid systems show promising therapeutic potential, further mechanistic studies, standardized characterization, and comprehensive in vivo investigations are necessary to confirm their reproducibility and translational relevance.

The hybrid and drug-combination systems summarized in Table 2 above highlight the increasing interest in utilizing AgNPs as multifunctional platforms for synergistic LC therapy. In these reported studies, integrating AgNPs with chemotherapeutic agents or secondary NMs enhances anticancer efficacy by improving drug delivery, increasing cellular uptake, and amplifying ROS-mediated apoptotic signaling in LC cells. Despite these promising outcomes, several methodological limitations persist. Most investigations assess therapeutic efficacy using a limited number of LC cell lines, predominantly A549 or H1299, without evaluating performance across a broader range of genetically diverse LC models. Furthermore, normal lung epithelial controls are not consistently included, which restricts the clear assessment of cancer selectivity and potential off-target toxicity. In addition, relatively high NP or drug concentrations are frequently used to demonstrate synergistic effects, raising concerns about the clinical relevance of the reported doses. Importantly, only a small proportion of hybrid AgNP systems have been validated in animal tumor models, and comprehensive studies addressing pharmacokinetics, biodistribution, and long-term toxicity remain scarce. Collectively, these limitations emphasize the need for more standardized experimental frameworks, clinically relevant dosing strategies, and rigorous in vivo validation to advance Ag-based hybrid nanoplatforms toward translational application.

8. Clinically approved nanoformulations and early clinical investigations of AgNPs

Several nanomedicine formulations have successfully reached the clinical stages, demonstrating the translational potential of NP-based therapies for cancer treatment. Among the FDA-approved nanodrugs, Doxil (liposomal doxorubicin) was the first nanocarrier system approved for ovarian cancer and Kaposi's sarcoma, followed by ‘Abraxane’ (albumin-bound paclitaxel) for breast and LC, and ‘Onivyde’ (liposomal irinotecan) for pancreatic cancer. Additionally, Vyxeos (liposomal daunorubicin/cytarabine) represents a successful example of combination nanotherapy with synchronized drug delivery, used to treat specific types of acute myeloid leukemia (AML) in adults and children.^210,211 These formulations exhibit improved pharmacokinetic profiles, enhanced tumor accumulation through the EPR effect, and reduced systemic toxicity compared to their conventional counterparts.

While most of the studies on AgNPs remain at the pre-clinical stage, recent work has begun to highlight translational efforts specific to Ag-based nanomedicines. A recent review of the clinical translation landscape of AgNPs notes that although Ag-nano constructs have been extensively investigated in vitro and in vivo, therapeutic clinical trials for cancer applications are still extremely limited. For example, most clinical studies to date have involved topical or antimicrobial use of AgNPs rather than systemic administration for oncology.^212,213 Pre-clinical studies demonstrate promising anticancer activity; for instance, AgNPs show selective cytotoxicity in aggressive cancers, such as triple-negative breast cancer and lung carcinoma cell lines.²¹⁴ However, no registered Phase III clinical trial has been reported for AgNPs in LC therapy. This gap underscores the urgent need to connect the design of AgNP-based systems (e.g., size control, surface functionalization, drug loading) with realistic clinical endpoints, safety profiles, manufacturing scalability, and regulatory pathways.

9. Toxicity, challenges and future directions

In LC, AgNPs have demonstrated the ability to induce cancer cell death, but their therapeutic utility is limited by their toxicity, particularly within the highly sensitive pulmonary environment.^215,216 The respiratory system is highly sensitive to inhaled NPs due to its extensive surface area and thin alveolar-capillary barriers. Achieving targeted delivery through inhalation routes remains difficult. In some studies, AgNPs reportedly caused acute and chronic pulmonary inflammation, pulmonary edema, alveolar wall thickening and fibrosis.^75,217 Although AgNPs show promising anticancer effects against LC in preclinical models, physiological and toxicological issues pose significant barriers to their clinical application.

9.1. Non-specific pulmonary toxicity

Despite the claims of selective toxicity toward cancer cells, another aspect of AgNPs is their detrimental impact on normal pulmonary epithelium and macrophages, activated by oxidative stress and mitochondrial damage, which is evidence of prominent non-selective cytotoxicity.^70,218 Extended exposure triggers fibrotic reactions and inflammatory cytokines (IL-6, TNF-α), suggesting substantial non-specific damage.²¹⁹ Future studies should focus on improving the selectivity of AgNPs towards tumor cells by incorporating tumor-targeting ligands and biocompatible surface coatings, such as polyethylene glycol or albumin. Additionally, systematic comparisons between LC cells and normal lung epithelial cells should be performed to better define therapeutic windows and minimize off-target toxicity.

9.2. Biodistribution and Ag⁺-ion fate

The physicochemical characteristics of AgNPs, such as size, morphology, agglomeration behavior, and surface charges, also affect their biological interaction, making reproducibility and dose optimization difficult.²²⁰ Their small size permits them to penetrate deep into the alveolar areas, where they can aggregate and produce genotoxic effects, such as DNA strand breaks and chromosomal abnormalities.²¹⁵ Past studies have demonstrated the fact that AgNPs have a low clearance rate and are capable of being stored in extrapulmonary organs, such as kidneys, spleen, and liver, among other organs, which raises the issue of longevity and systemic toxicity after lung delivery.^221,222 Such persistence may also raise the question of their ability to induce resistance mechanisms in tumor cells and also their interaction with other drugs that are co-administered or with biological molecules. Poor knowledge of their metabolism, excretion, and the biological fate of released Ag⁺ ions further complicates safety studies and long-term toxicological evaluation.²²³ Chronic exposure to Ag compounds causes risk known as ‘argyria’, characterized by permanent blue-gray pigmentation of the skin and eyes. Future research should, therefore, prioritize comprehensive pharmacokinetic and biodistribution studies, including quantitative tracking of Ag⁺ ions, to better understand NP metabolism, clearance mechanisms, and potential systemic toxicity.

9.3. Interspecies differences in preclinical models

Differences in the murine and human lung structures and the clearance mechanisms reduce the precision of using in vivo findings for human predictions. The lack of extensive pharmacokinetic and biodistribution information, species-specific metabolism, and information on what happens to Ag⁺ ions all contribute to impeding the clinical translation. Hence, humanized lung models and specific drug regimens need to be developed to ensure selective delivery, clearance assurance, and safety of future therapy interventions.²²⁴

9.4. Scale-up and batch variability

In addition to such biological constraints, the scalability and reproducibility of NP synthesis represent other significant hindrances to clinical translation. Techniques optimized in the laboratory may not be reproducible at large scale in terms of uniform morphology and functionalization, and this can cause changes in biological activity and safety. Also, as the cost of large-scale manufacturing is high and no standardized regulatory frameworks and manufacturing protocols exist, implementing quality assurance, risk assessment, and approval procedures for AgNP-based formulations is difficult.^225,226 Future work should, therefore, focus on developing scalable and reproducible NP synthesis strategies, along with standardized characterization protocols to ensure consistent physicochemical properties across production batches.

9.5. Regulatory considerations and future strategies

The absence of standardized regulatory frameworks for NMs further complicates the clinical translation of AgNP-based formulations. High production costs, limited manufacturing guidelines, and insufficient long-term safety data pose significant challenges for regulatory approval.²²⁷ To overcome these barriers, future studies should emphasize internationally standardized toxicity testing protocols, detailed NP characterization, and long-term in vivo safety studies. Additionally, strategies, such as controlled release systems for regulated Ag⁺ ion delivery, green synthesis approaches, and targeted functionalization, may help reduce toxicity while enhancing therapeutic efficacy. These efforts will be essential to advance AgNP-based nanotherapeutics from experimental research to safe and effective clinical applications for LC treatment.

10. Conclusions

AgNPs are extremely versatile multi-functional platforms that have considerable potential to transform LC nanotherapy due to their outstanding physicochemical properties, including their tunable size and morphology, optimal surface charge, easy functionalization and enhanced anticancer effect. This review highlights the critical role of the synthesis procedures and characterization techniques that enable the accurate regulation of the morphology and surface functionality of AgNPs, which in turn govern their biocompatibility, solubility, cellular uptake, and biodistribution in LC-targeted nano therapies. AgNPs enter LC cells through passive diffusion or receptor-mediated endocytosis, where they elevate ROS and cause mitochondrial dysfunction, ER stress, and intrinsic apoptosis. Prolonged damage triggers autophagy and G2/M transition arrest governed by p53/p21, which eventually results in apoptosis or necrosis of cancerous cells under extreme stress. In addition, AgNPs demonstrate a strong synergistic effect with established chemotherapeutic agents, natural products, and other NMs, minimizing the adverse side effects without disrupting or preventing the anticancer activity; this makes them the best candidate for use in multifunctional cancer therapeutics. Although AgNPs have the potential to be therapeutically beneficial, they also have extensive off-target effects on normal pulmonary epithelial and immune cells, which pose a major translational barrier. Therefore, several key priorities must be addressed to advance AgNP-based nanotherapeutics towards clinical application. The development and adoption of physiologically relevant in vitro lung models, such as air–liquid interface cultures, organoids, and lung-on-chip systems, are essential for more accurate evaluation of efficacy and toxicity. Standardized toxicological and pharmacokinetic frameworks are needed to enable reliable comparison across studies and to better understand biodistribution, clearance, and long-term safety. The establishment of rational design principles balancing therapeutic efficacy with controlled Ag⁺-ion release and minimized off-target effects will be critical for optimizing the NP performance. Additionally, greater emphasis should be placed on clinically relevant delivery strategies, particularly inhalation-based approaches, to ensure effective and targeted drug deposition in lung tissues. Addressing these priorities will be crucial for bridging the gap between experimental studies and the safe, effective clinical translation of AgNP-based formulations for LC treatment.

Conflicts of interest

The authors declare no conflicts of interest.

Abbreviations

5-FU	5-Fluorouracil
A2780	Ovarian cancer cell line
A549	Human lung adenocarcinoma cells
Abs	Antibodies
AC	A. calamus L.
ACC1	Acetyl-CoA carboxylase1
ACE 2	Angiotensin-converting enzyme 2
AFM	Atomic force microscopy
Ag	Silver
AgNPs	Silver nanoparticles
AML	Acute myeloid leukemia
AMPK	AMP-activated protein kinase
Au	Gold
BEAS-2B	Human non-tumorigenic lung epithelial cells
Bp	Bidens pilosa
CAPIR	Circulation, accumulation, penetration, internalization, and release
Car	Carboplatin
CIE	Clathrin-independent endocytosis
CIS	Cisplatin
CME	Clathrin-mediated endocytosis
CMT	Camptothecin
COX-2	Cyclooxygenase-2
CS	Chitosan
CuO	Copper oxide nanoparticles
CUR	Curcumin
CVM	Caveolin-mediated endocytosis
DNA PKcs	DNA-dependent protein kinases
DS	D. sissoo
ECM	Extra cellular matrix
Fe3O4	Ferrite nanoparticles
GLOBOCAN	Global cancer observatory
HS-PEG2K-NH2	Thiol polyethylene glycol amine
HUVECs	Human umbilical vein endothelial cells
IC50	Half-maximal inhibitory concentration
IMR90	Normal human lung fibroblasts
In2O3	Indium oxide
INH	Isonicotinic acid hydrazide
JNK	c-Jun N-terminal kinase
L132	Human embryonic lung epithelial cell line
L929	Adherent type of mouse fibroblast cell line
LC	Lung cancer
LC3	Microtubule associated protein
LK-2	Lung squamous carcinoma
MAPK	Mitogen-activated protein kinase
MPS	Mononuclear phagocyte system
mTOR	Mammalian target of rapamycin
MTT	3-(4,5-Dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide
MTX	Methotrexate
MVBs	Multivesicular bodies
NCPA	N-Cholyl D-penicillamine
NF-κb	Nuclear factor-Kappa B
NMs	Nanomaterials
NPs	Nanoparticles
NSCLC	Non-small cell lung cancer
PB	Piper betle
PDA	Polydopamine
PLGA	Poly lactic-co-glycolic acid
Pt	Platinum
PTX	Paclitaxel
PVP	Polyvinylpyrrolidone
RME	Receptor-mediated endocytosis
ROS	Reactive oxygen species
RTX	Raltitrexed
S6K	Ribosomal protein S6 kinase beta-1
SCLC	Small cell lung cancer
SCRBD	SARS-CoV-2 receptor binding domain
SEM	Scanning electron microscopy
SER	Smooth endoplasmic reticulum
SPR	Surface plasmon resonance
SQSTM1	Sequestosome 1
TEM	Transmission electron microscopy
TiO2	Titanium dioxide
TMC	N,N,N-Trimethyl chitosan chloride
TME	Tumor microenvironment
WI 38	Normal lung cell
ZnO	Zinc oxide

Data availability

The authors declare that the data supporting the findings of this study, including the newly generated figures and tables, are available within the article. Additional datasets are available from the corresponding author upon reasonable request.

Acknowledgements

The authors express their gratitude to their respective institutions for providing the research facilities necessary for this study. T. G. is thankful to the DST-Inspire Fellowship (IF200339) for the financial assistance.

References

1. Y. Peng-Winkler and S.-M. Fendt, Metabolic Adaptations in Cancer Progression, Physiol. Rev., 2026, 106(1), 1–51,  DOI:10.1152/physrev.00037.2024.
2. H. Arem and E. Loftfield, Cancer Epidemiology: A Survey of Modifiable Risk Factors for Prevention and Survivorship, Am. J. Lifestyle Med., 2018, 12(3), 200–210,  DOI:10.1177/1559827617700600.
3. S. Wu, W. Zhu, P. Thompson and Y. A. Hannun, Evaluating Intrinsic and Non-Intrinsic Cancer Risk Factors, Nat. Commun., 2018, 9(1), 3490,  DOI:10.1038/s41467-018-05467-z.
4. R. L. Siegel, K. D. Miller, H. E. Fuchs and A. Jemal, Cancer Statistics, 2022, Ca-Cancer J. Clin., 2022, 72(1), 7–33,  DOI:10.3322/caac.21708.
5. L. Guo, C. Zhu, L. Cai, X. Zhang, Y. Fang, H. Chen and H. Yang, Global Burden of Lung Cancer in 2022 and Projected Burden in 2050, Chin. Med. J., 2024, 137(21), 2577–2582,  DOI:10.1097/CM9.0000000000003268.
6. K. Phutela and S. Sharma, Non-Small Cell Lung Carcinoma (NSCLC) and Underlying Causes, in Advancements in the Diagnostics and Therapeutics for Non-Small Cell Lung Carcinoma (NSCLC), ed. P. Singh, S. P. Kollur and R. G. Amachawadi, IGI Global Scientific Publishing, 2025, pp. 1–42 DOI:10.4018/979-8-3373-2096-0.ch001.
7. C. Petrasso, J. Bayly, L. Fettes, S. Ashford and M. Maddocks, Interplay between Mobility, Social Participation, and Symptom Burden in Advanced Lung Cancer, Support Care Cancer, 2026, 34(1), 42,  DOI:10.1007/s00520-025-10269-3.
8. K. Yang, H. Wei, W. Zhu, Y. Xu, S. Wang, F. Fan, K. Zhang, Q. Yuan and H. Wang, Clinical Characteristics and Risk Factors of Late-Stage Lung Adenocarcinoma Patients with Bacterial Pulmonary Infection and Its Relationship with Cellular Immune Function, Front. Immunol., 2025, 16, 1559211,  DOI:10.3389/fimmu.2025.1559211.
9. P. Cao, L. Chen, S. Xie and B. Hu, Advances in Diagnosis and Treatment of Lung Cancer-Associated Obstructive Pneumonia and Lung Abscess: Synergistic Strategies for Infection Control and Antitumor Therapy, Front. Cell. Infect. Microbiol., 2025, 15, 1638997,  DOI:10.3389/fcimb.2025.1638997.
10. Current Role of Nanoparticles in the Treatment of Lung Cancer, J. Clin. Transl. Res., 2021 DOI:10.18053/jctres.07.202102.005.
11. B. D. Kozower, J. M. Larner, F. C. Detterbeck and D. R. Jones, Special Treatment Issues in Non-Small Cell Lung Cancer, Chest, 2013, 143(5), e369S–e399S,  DOI:10.1378/chest.12-2362.
12. N. Solanki, P. Shah, S. Kewalramani, U. Shah, M. Patel, S. Patel and R. Maheshwari, Emerging Anti-Cancer and Repurposed Therapies for Overcoming Multidrug Resistance in Lung Cancer, Med. Oncol., 2025, 43(2), 100,  DOI:10.1007/s12032-025-03208-z.
13. M. S. Hussain, P. A. Mir, N. Kumar, R. Mohi-ud-din, A. F. Wali, R. H. Mir, S. Talath, S. B. Sridhar, J. Shareef, M. Goud, I. Rangraze and M. El-Tanani, From Lab to Clinic: Success Stories of Repurposed Drugs in Treating Major Diseases, Adv. Pharmacol. Pharm. Sci., 2025, 2025(1), 1070716,  DOI:10.1155/adpp/1070716.
14. A. Sharma, D. Shambhwani, S. Pandey, J. Singh, H. Lalhlenmawia, M. Kumarasamy, S. K. Singh, D. K. Chellappan, G. Gupta, P. Prasher, K. Dua and D. Kumar, Advances in Lung Cancer Treatment Using Nanomedicines, ACS Omega, 2023, 8(1), 10–41,  DOI:10.1021/acsomega.2c04078.
15. Advanced Drug Delivery Systems in the Management of Cancer, ed. K. Dua, M. Mehta, T. de Jesus Andreoli Pinto, L. G. Pont, K. A. Williams and M. J. Rathbone, Elsevier, 2021 DOI:10.1016/C2020-0-02697-6.
16. R. Mohi-ud-din, A. Chawla, P. Sharma, P. A. Mir, F. H. Potoo, Ž. Reiner, I. Reiner, D. A. Ateşşahin, J. Sharifi-Rad, R. H. Mir and D. Calina, Repurposing Approved Non-Oncology Drugs for Cancer Therapy: A Comprehensive Review of Mechanisms, Efficacy, and Clinical Prospects, Eur. J. Med. Res., 2023, 28(1), 345,  DOI:10.1186/s40001-023-01275-4.
17. H. Lee, K. Sajid and J. Lee, Engineered Nanocarriers for Targeted Lung Cancer Therapy: Mechanistic Innovations and Recent Clinical Progress, Explor. Targeted Antitumor Ther., 2025, 6, 1002339,  DOI:10.37349/etat.2025.1002339.
18. A. Li, Z. Yue, D. Li and H. Zheng, Biomaterials for Cancer Therapy: Design Strategies, Therapeutic Mechanisms, Recent Advances, and Future Challenges, Acad. Mater. Sci., 2025, 2(4) DOI:10.20935/AcadMatSci8086.
19. A. Barhoum, M. L. García-Betancourt, J. Jeevanandam, E. A. Hussien, S. A. Mekkawy, M. Mostafa, M. M. Omran, M. S. Abdalla and M. Bechelany, Review on Natural, Incidental, Bioinspired, and Engineered Nanomaterials: History, Definitions, Classifications, Synthesis, Properties, Market, Toxicities, Risks, and Regulations, Nanomaterials, 2022, 12(2), 177,  DOI:10.3390/nano12020177.
20. A. M. El-Khawaga, A. Zidan and A. I. A. A. El-Mageed, Preparation Methods of Different Nanomaterials for Various Potential Applications: A Review, J. Mol. Struct., 2023, 1281, 135148,  DOI:10.1016/j.molstruc.2023.135148.
21. R. Liu, C. Luo, Z. Pang, J. Zhang, S. Ruan, M. Wu, L. Wang, T. Sun, N. Li, L. Han, J. Shi, Y. Huang, W. Guo, S. Peng, W. Zhou and H. Gao, Advances of Nanoparticles as Drug Delivery Systems for Disease Diagnosis and Treatment, Chin. Chem. Lett., 2023, 34(2), 107518,  DOI:10.1016/j.cclet.2022.05.032.
22. S. Singh, S. Sewariya, T. Goel, S. Panchal, A. Singh, S. Kukreti, M. Tiwari and R. Chandra, Assessing Dual Drug 9-Hydroxymethyl Noscapine and Telmisartan-Loaded Stearic Acid Nanoparticles against (H1299) Non-Small Cell Lung Cancer and Their Mechanistic Interaction with Bovine Serum Albumin, Mater. Adv., 2025, 6(4), 1364–1378,  10.1039/D4MA00958D.
23. M. Bordoni, E. Scarian, F. Rey, S. Gagliardi, S. Carelli, O. Pansarasa and C. Cereda, Biomaterials in Neurodegenerative Disorders: A Promising Therapeutic Approach, Int. J. Mol. Sci., 2020, 21(9), 3243,  DOI:10.3390/ijms21093243.
24. N. A. Mohamed, I. Marei, S. Crovella and H. Abou-Saleh, Recent Developments in Nanomaterials-Based Drug Delivery and Upgrading Treatment of Cardiovascular Diseases, Int. J. Mol. Sci., 2022, 23(3), 1404,  DOI:10.3390/ijms23031404.
25. M. Vallet-Regí, B. González and I. Izquierdo-Barba, Nanomaterials as Promising Alternative in the Infection Treatment, Int. J. Mol. Sci., 2019, 20(15), 3806,  DOI:10.3390/ijms20153806.
26. L. Gao, L.-H. Yang, F.-C. Jiang, W.-Y. Ye, X. Chen, Z.-J. Liu, R.-Q. He, W.-Y. Huang, Z.-B. Feng, J.-L. Kong, Z.-F. Lai and G. Chen, Photothermal Therapeutic Gold Nanoparticles Loaded with PD-L1 siRNA Enhanced Killing of NSCLC Cells by Immune Cells, Int. J. Nanomed., 2025, 20, 8833–8859,  DOI:10.2147/IJN.S518427.
27. S. Rajeshkumar, S. V. Kumar, A. Ramaiah, H. Agarwal, T. Lakshmi and S. M. Roopan, Biosynthesis of Zinc Oxide Nanoparticles usingMangifera Indica Leaves and Evaluation of Their Antioxidant and Cytotoxic Properties in Lung Cancer (A549) Cells, Enzyme Microb. Technol., 2018, 117, 91–95,  DOI:10.1016/j.enzmictec.2018.06.009.
28. Y. Wang, H. Cui, J. Zhou, F. Li, J. Wang, M. Chen and Q. Liu, Cytotoxicity, DNA Damage, and Apoptosis Induced by Titanium Dioxide Nanoparticles in Human Non-Small Cell Lung Cancer A549 Cells, Environ. Sci. Pollut. Res., 2015, 22(7), 5519–5530,  DOI:10.1007/s11356-014-3717-7.
29. A. Kalaiarasi, R. Sankar, C. Anusha, K. Saravanan, K. Aarthy, S. Karthic, T. L. Mathuram and V. Ravikumar, Copper Oxide Nanoparticles Induce Anticancer Activity in A549 Lung Cancer Cells by Inhibition of Histone Deacetylase, Biotechnol. Lett., 2018, 40(2), 249–256,  DOI:10.1007/s10529-017-2463-6.
30. P. K. Khangar and V. Daniel, Advanced Approaches in Lung Cancer Therapy–Exploring the Unique Role of Multiwalled Carbon Nanotubes, Next Nanotechnol., 2025, 7, 100180,  DOI:10.1016/j.nxnano.2025.100180.
31. R. Liao, Y. Zhang and W. Mao, Functionalized Graphene Oxide NPs as a Nanocarrier for Drug Delivery System in Quercetin/Lurbinectedin as Dual Sensitive Therapeutics for A549 Lung Cancer Treatment, Heliyon, 2024, 10(11), e31212,  DOI:10.1016/j.heliyon.2024.e31212.
32. S. Kakavandi, I. Zare, N. Esmaeilnejad, M. Sarhadi, A. Hheidari, S. Shojaei, Y. Fatahi, M. Mirshafiei, M. Zhang, F. Sharifianjazi, K. Zheng, K. Tavamaishvili, M. Iranpour, C. Kim, S. Zanganeh, R. Thangampillai Senthilkumar, B. R. Smith, R. Dinarvand, H. Rashedi, M. Yu, H. Kang and P. Makvandi, PLGA-Integrated Micro/Nanoparticles for Cargo Delivery and Nanomedicine of Lung Cancer, Int. J. Pharm., 2026, 687, 126339,  DOI:10.1016/j.ijpharm.2025.126339.
33. D. Fang, H. Jin, X. Huang, Y. Shi, Z. Liu and S. Ben, PPy@Fe₃O₄ Nanoparticles Inhibit Tumor Growth and Metastasis Through Chemodynamic and Photothermal Therapy in Non-Small Cell Lung Cancer, Front. Chem., 2021, 9, 789934,  DOI:10.3389/fchem.2021.789934.
34. Q. Gao, J. Zhang, J. Gao, Z. Zhang, H. Zhu and D. Wang, Gold Nanoparticles in Cancer Theranostics, Front. Bioeng. Biotechnol., 2021, 9, 647905,  DOI:10.3389/fbioe.2021.647905.
35. H. L. Karlsson, P. Cronholm, J. Gustafsson and L. Möller, Copper Oxide Nanoparticles Are Highly Toxic: A Comparison between Metal Oxide Nanoparticles and Carbon Nanotubes, Chem. Res. Toxicol., 2008, 21(9), 1726–1732,  DOI:10.1021/tx800064j.
36. H. Shi, R. Magaye, V. Castranova and J. Zhao, Titanium Dioxide Nanoparticles: A Review of Current Toxicological Data, Part. Fibre Toxicol., 2013, 10(1), 15,  DOI:10.1186/1743-8977-10-15.
37. M. Salehirozveh, P. Dehghani and I. Mijakovic, Synthesis, Functionalization, and Biomedical Applications of Iron Oxide Nanoparticles (IONPs), J. Funct. Biomater., 2024, 15(11), 340,  DOI:10.3390/jfb15110340.
38. M. Algarra, S. Vinacua, A. Gil-Korilis and A. Gil, Recent Developments in the Use of Carbon-Based Nanomaterials in Cancer Therapy, J. Controlled Release, 2025, 386, 114100,  DOI:10.1016/j.jconrel.2025.114100.
39. I. Laib, N. Gheraissa, A. Benaissa, L. Benkhira, M. Azzi, Y. Benaissa, A. G. Abdelaziz, F. Tian, M. Walsh, M. Bechelany and A. Barhoum, Tailoring Innovative Silver Nanoparticles for Modern Medicine: The Importance of Size and Shape Control and Functional Modifications, Mater. Today Bio, 2025, 33, 102071,  DOI:10.1016/j.mtbio.2025.102071.
40. K. Alaqad and T. A. Saleh, Gold and Silver Nanoparticles: Synthesis Methods, Characterization Routes and Applications towards Drugs, J. Environ. Anal. Toxicol., 2016, 6(4) DOI:10.4172/2161-0525.1000384.
41. S. Medici, M. Peana, V. M. Nurchi and M. A. Zoroddu, Medical Uses of Silver: History, Myths, and Scientific Evidence, J. Med. Chem., 2019, 62(13), 5923–5943,  DOI:10.1021/acs.jmedchem.8b01439.
42. D. Kovács, N. Igaz, M. K. Gopisetty and M. Kiricsi, Cancer Therapy by Silver Nanoparticles: Fiction or Reality?, Int. J. Mol. Sci., 2022, 23(2), 839,  DOI:10.3390/ijms23020839.
43. M. Abass Sofi, S. Sunitha, M. Ashaq Sofi, S. K. Khadheer Pasha and D. Choi, An Overview of Antimicrobial and Anticancer Potential of Silver Nanoparticles, J. King Saud Univ., Sci., 2022, 34(2), 101791,  DOI:10.1016/j.jksus.2021.101791.
44. N. Kanipandian, D. Li and S. Kannan, Induction of Intrinsic Apoptotic Signaling Pathway in A549 Lung Cancer Cells Using Silver Nanoparticles from Gossypium Hirsutum and Evaluation of in Vivo Toxicity, Biotechnol. Rep., 2019, 23, e00339,  DOI:10.1016/j.btre.2019.e00339.
45. X. Chang, X. Wang, J. Li, M. Shang, S. Niu, W. Zhang, Y. Li, Z. Sun, J. Gan, W. Li, M. Tang and Y. Xue, Silver Nanoparticles Induced Cytotoxicity in HT22 Cells through Autophagy and Apoptosis via PI3K/AKT/mTOR Signaling Pathway, Ecotoxicol. Environ. Saf., 2021, 208, 111696,  DOI:10.1016/j.ecoenv.2020.111696.
46. V. R. Narasimha, T. S. Latha, R. Pallu, K. Panati and V. R. Narala, Anticancer Activities of Biogenic Silver Nanoparticles Targeting Apoptosis and Inflammatory Pathways in Colon Cancer Cells, J. Cluster Sci., 2022, 33(5), 2215–2231,  DOI:10.1007/s10876-021-02143-z.
47. N. Ivanova, V. Gugleva, M. Dobreva, I. Pehlivanov, S. Stefanov and V. Andonova, Silver Nanoparticles as Multi-Functional Drug Delivery Systems, in Nanomedicines, ed. M. Akhyar Farrukh, IntechOpen, 2019 DOI:10.5772/intechopen.80238.
48. L. Wei, J. Lu, H. Xu, A. Patel, Z.-S. Chen and G. Chen, Silver Nanoparticles: Synthesis, Properties, and Therapeutic Applications, Drug Discovery Today, 2015, 20(5), 595–601,  DOI:10.1016/j.drudis.2014.11.014.
49. N. Parvin, M. Aslam, M. N. Alam and T. K. Mandal, Nanotechnology Driven Innovations in Modern Pharmaceutics: Therapeutics, Imaging, and Regeneration, Nanomaterials, 2025, 15(22), 1733,  DOI:10.3390/nano15221733.
50. J. L. Mejía-Méndez, E. R. López-Mena and E. Sánchez-Arreola, Activities against Lung Cancer of Biosynthesized Silver Nanoparticles: A Review, Biomedicines, 2023, 11(2), 389,  DOI:10.3390/biomedicines11020389.
51. Y. Sharma, P. Rajput, A. Brahma, T. Goel, A. Singh, J. Madan, R. Kumar Ratnesh, R. Chandra and S. Singh, Synergizing Nanotechnology with Biomedical and Biotechnology for Healthcare, in Nanotechnology Applications for Industry 4.0, CRC Press, Boca Raton, 2025, pp. 108–145 DOI:10.1201/9781003634553-5.
52. S. Gavas, S. Quazi and T. M. Karpiński, Nanoparticles for Cancer Therapy: Current Progress and Challenges, Nanoscale Res. Lett., 2021, 16(1), 173,  DOI:10.1186/s11671-021-03628-6.
53. O. Pryshchepa, P. Pomastowski and B. Buszewski, Silver Nanoparticles: Synthesis, Investigation Techniques, and Properties, Adv. Colloid Interface Sci., 2020, 284, 102246,  DOI:10.1016/j.cis.2020.102246.
54. L. Krishnia, P. Thakur and A. Thakur, Synthesis of Nanoparticles by Physical Route, in Synthesis and Applications of Nanoparticles, ed. A. Thakur, P. Thakur and S. M. P. Khurana, Springer Nature Singapore, Singapore, 2022, pp. 45–59 DOI:10.1007/978-981-16-6819-7_3.
55. M. Noga, J. Milan, A. Frydrych and K. Jurowski, Toxicological Aspects, Safety Assessment, and Green Toxicology of Silver Nanoparticles (AgNPs)—Critical Review: State of the Art, Int. J. Mol. Sci., 2023, 24(6), 5133,  DOI:10.3390/ijms24065133.
56. H. Duman, F. Eker, E. Akdaşçi, A. M. Witkowska, M. Bechelany and S. Karav, Silver Nanoparticles: A Comprehensive Review of Synthesis Methods and Chemical and Physical Properties, Nanomaterials, 2024, 14(18), 1527,  DOI:10.3390/nano14181527.
57. N. T. K. Thanh, N. Maclean and S. Mahiddine, Mechanisms of Nucleation and Growth of Nanoparticles in Solution, Chem. Rev., 2014, 114(15), 7610–7630,  DOI:10.1021/cr400544s.
58. J. Lee, J. Yang, S. G. Kwon and T. Hyeon, Nonclassical Nucleation and Growth of Inorganic Nanoparticles, Nat. Rev. Mater., 2016, 1(8), 16034,  DOI:10.1038/natrevmats.2016.34.
59. R. Javed, M. Zia, S. Naz, S. O. Aisida, N. U. Ain and Q. Ao, Role of Capping Agents in the Application of Nanoparticles in Biomedicine and Environmental Remediation: Recent Trends and Future Prospects, J. Nanobiotechnol., 2020, 18(1), 172,  DOI:10.1186/s12951-020-00704-4.
60. R. H. Mir, M. Maqbool, P. A. Mir, Md. S. Hussain, S. U. Din Wani, F. H. Pottoo and R. Mohi-ud-din, Green Synthesis of Silver Nanoparticles and Their Potential Applications in Mitigating Cancer, Curr. Pharm. Des., 2024, 30(31), 2445–2467,  DOI:10.2174/0113816128291705240428060456.
61. S. Dawadi, S. Katuwal, A. Gupta, U. Lamichhane, R. Thapa, S. Jaisi, G. Lamichhane, D. P. Bhattarai and N. Parajuli, Current Research on Silver Nanoparticles: Synthesis, Characterization, and Applications, J. Nanomater., 2021, 2021(1), 6687290,  DOI:10.1155/2021/6687290.
62. B. Khodashenas and H. R. Ghorbani, Synthesis of Silver Nanoparticles with Different Shapes, Arabian J. Chem., 2019, 12(8), 1823–1838,  DOI:10.1016/j.arabjc.2014.12.014.
63. Z. P. Aguilar, Types of Nanomaterials and Corresponding Methods of Synthesis, in Nanomaterials for Medical Applications, Elsevier, 2013, pp. 33–82 DOI:10.1016/B978-0-12-385089-8.00002-9.
64. B. K. Mehta, M. Chhajlani and B. D. Shrivastava, Green Synthesis of Silver Nanoparticles and Their Characterization by XRD, J. Phys.: Conf. Ser., 2017, 836, 012050,  DOI:10.1088/1742-6596/836/1/012050.
65. Surface-Plasmon-Resonance-of-Silver-Nanoparticles-Synthesis-Characterization-and-Applications.Pdf. https://jbiochemtech.com/storage/models/article/6clSitkCxA2emGy003WaVlqerU4hsUiLvhifoQmc9mVvMZPKMu2RdTF7l84K/surface-plasmon-resonance-of-silver-nanoparticles-synthesis-characterization-and-applications.pdf (accessed 2025-11-06).
66. S. S. Royji Albeladi, M. A. Malik and S. A. Al-thabaiti, Facile Biofabrication of Silver Nanoparticles Using Salvia Officinalis Leaf Extract and Its Catalytic Activity towards Congo Red Dye Degradation, J. Mater. Res. Technol., 2020, 9(5), 10031–10044,  DOI:10.1016/j.jmrt.2020.06.074.
67. B. J. Wiley, S. H. Im, Z.-Y. Li, J. McLellan, A. Siekkinen and Y. Xia, Maneuvering the Surface Plasmon Resonance of Silver Nanostructures through Shape-Controlled Synthesis, J. Phys. Chem. B, 2006, 110(32), 15666–15675,  DOI:10.1021/jp0608628.
68. A. Rautela, J. Rani and M. Debnath (Das), Green Synthesis of Silver Nanoparticles from Tectona Grandis Seeds Extract: Characterization and Mechanism of Antimicrobial Action on Different Microorganisms, J. Anal. Sci. Technol., 2019, 10(1), 5,  DOI:10.1186/s40543-018-0163-z.
69. S. A. Sadat Shandiz, M. Shafiee Ardestani, D. Shahbazzadeh, A. Assadi, R. Ahangari Cohan, V. Asgary and S. Salehi, Novel Imatinib-Loaded Silver Nanoparticles for Enhanced Apoptosis of Human Breast Cancer MCF-7 Cells, Artif. Cells, Nanomed., Biotechnol., 2016, 45(6), 1082–1091,  DOI:10.1080/21691401.2016.1202257.
70. H. J. Johnston, G. Hutchison, F. M. Christensen, S. Peters, S. Hankin and V. Stone, A Review of the in Vivo and in Vitro Toxicity of Silver and Gold Particulates: Particle Attributes and Biological Mechanisms Responsible for the Observed Toxicity, Crit. Rev. Toxicol., 2010, 40(4), 328–346,  DOI:10.3109/10408440903453074.
71. K. Dua, S. D. Shukla, T. De Jesus Andreoli Pinto and P. M. Hansbro, Nanotechnology: Advancing the Translational Respiratory Research, Interventional Med. Appl. Sci., 2017, 9(1), 39–41,  DOI:10.1556/1646.9.2017.1.02.
72. Y. M. Que, X. Q. Fan, X. J. Lin, X. L. Jiang, P. P. Hu, X. Y. Tong and Q. Y. Tan, Size Dependent Anti-Invasiveness of Silver Nanoparticles in Lung Cancer Cells, RSC Adv., 2019, 9(37), 21134–21138,  10.1039/C9RA03662H.
73. J. Y. Cheon, S. J. Kim, Y. H. Rhee, O. H. Kwon and W. H. Park, Shape-Dependent Antimicrobial Activities of Silver Nanoparticles, Int. J. Nanomed., 2019, 14, 2773–2780,  DOI:10.2147/IJN.S196472.
74. Z. Qiao, Y. Yao, S. Song, M. Yin and J. Luo, Silver Nanoparticles with pH Induced Surface Charge Switchable Properties for Antibacterial and Antibiofilm Applications, J. Mater. Chem. B, 2019, 7(5), 830–840,  10.1039/C8TB02917B.
75. L. Xu, Y.-Y. Wang, J. Huang, C.-Y. Chen, Z.-X. Wang and H. Xie, Silver Nanoparticles: Synthesis, Medical Applications and Biosafety, Theranostics, 2020, 10(20), 8996–9031,  DOI:10.7150/thno.45413.
76. H. Wang, K. B. Li, C. Xu, S. C. Xu and G. H. Li, Large-Scale Solvothermal Synthesis of Ag Nanocubes with High SERS Activity, J. Alloys Compd., 2019, 772, 150–156,  DOI:10.1016/j.jallcom.2018.09.043.
77. H. Liang, W. Wang, Y. Huang, S. Zhang, H. Wei and H. Xu, Controlled Synthesis of Uniform Silver Nanospheres, J. Phys. Chem. C, 2010, 114(16), 7427–7431,  DOI:10.1021/jp9105713.
78. B. J. Wiley, Y. Chen, J. M. McLellan, Y. Xiong, Z.-Y. Li, D. Ginger and Y. Xia, Synthesis and Optical Properties of Silver Nanobars and Nanorice, Nano Lett., 2007, 7(4), 1032–1036,  DOI:10.1021/nl070214f.
79. J. Zhang, M. R. Langille and C. A. Mirkin, Synthesis of Silver Nanorods by Low Energy Excitation of Spherical Plasmonic Seeds, Nano Lett., 2011, 11(6), 2495–2498,  DOI:10.1021/nl2009789.
80. Z. Zhang, J. Yu, J. Zhang, Y. Lian, Z. Shi, Z. Cheng and M. Gu, pH-Controlled Growth of Triangular Silver Nanoprisms on a Large Scale, Nanoscale Adv., 2019, 1(12), 4904–4908,  10.1039/C9NA00635D.
81. M. C. Nguyen, T. Q. Ngan Luong, T. T. Vu, C. T. Anh and T. C. Dao, Synthesis of Wool Roll-like Silver Nanoflowers in an Ethanol/Water Mixture and Their Application to Detect Traces of the Fungicide Carbendazim by SERS Technique, RSC Adv., 2022, 12(19), 11583–11590,  10.1039/D1RA09286C.
82. C. J. Murphy and N. R. Jana, Controlling the Aspect Ratio of Inorganic Nanorods and Nanowires, Adv. Mater., 2002, 14(1), 80–82,  DOI:10.1002/1521-4095(20020104)14:1%253C80::AID-ADMA80%253E3.0.CO;2-%2523.
83. A. Garcia-Leis, J. V. Garcia-Ramos and S. Sanchez-Cortes, Silver Nanostars with High SERS Performance, J. Phys. Chem. C, 2013, 117(15), 7791–7795,  DOI:10.1021/jp401737y.
84. A. Zeb, M. Gul, T.-T.-L. Nguyen and H.-J. Maeng, Recent Progress and Drug Delivery Applications of Surface-Functionalized Inorganic Nanoparticles in Cancer Therapy, J. Pharm. Invest., 2023, 53(6), 743–779,  DOI:10.1007/s40005-023-00632-z.
85. A. Zeb, M. Gul, T.-T.-L. Nguyen and H.-J. Maeng, Recent Progress and Drug Delivery Applications of Surface-Functionalized Inorganic Nanoparticles in Cancer Therapy, J. Pharm. Invest., 2023, 53(6), 743–779,  DOI:10.1007/s40005-023-00632-z.
86. P. Chandra Kanth, S. K. Verma and N. Gour, Functionalized Nanomaterials for Biomedical and Agriculture Industries, in Handbook of Functionalized Nanomaterials for Industrial Applications, Elsevier, 2020, pp. 231–265 DOI:10.1016/B978-0-12-816787-8.00010-7.
87. M. M. Abdel-Aziz, M. H. A. Elella and R. R. Mohamed, Green Synthesis of Quaternized Chitosan/Silver Nanocomposites for Targeting Mycobacterium Tuberculosis and Lung Carcinoma Cells (A-549, Int. J. Biol. Macromol., 2020, 142, 244–253,  DOI:10.1016/j.ijbiomac.2019.09.096.
88. V. Gopinath, D. MubarakAli, J. Vadivelu, S. Manjunath Kamath, A. Syed and A. M. Elgorban, Synthesis of Biocompatible Chitosan Decorated Silver Nanoparticles Biocomposites for Enhanced Antimicrobial and Anticancer Property, Process Biochem., 2020, 99, 348–356,  DOI:10.1016/j.procbio.2020.09.011.
89. D. Bharathi, J. G. Thiruvengadam Nandagopal, J. Lee and R. Ranjithkumar, Facile Synthesis and Characterization of Chitosan Functionalized Silver Nanoparticles for Antibacterial and Anti-Lung Cancer Applications, Polymers, 2023, 15(12), 2700,  DOI:10.3390/polym15122700.
90. S. Pushpanathan, S. Yahya, A. Gunasekaran, S. R. Natarajan, K. Kannan and K. Krishnan, Caffeic Acid Functionalized Silver Nanoparticles: A Bionanoformulation and Its Assessment of Cell Cycle and in Vitro Cytotoxicity, Next Nanotechnol., 2025, 7, 100105,  DOI:10.1016/j.nxnano.2024.100105.
91. G. Baskar, G. Bikku George and M. Chamundeeswari, Synthesis and Characterization of Asparaginase Bound Silver Nanocomposite Against Ovarian Cancer Cell Line A2780 and Lung Cancer Cell Line A549, J. Inorg. Organomet. Polym., 2017, 27(1), 87–94,  DOI:10.1007/s10904-016-0448-x.
92. A. Umapathi, H. Madhyastha, P. N. Navya, M. Singh, R. Madhyastha and H. K. Daima, Surface Chemistry Driven Selective Anticancer Potential of Functional Silver Nanoparticles toward Lung Cancer Cells, Colloids Surf., A, 2022, 652, 129809,  DOI:10.1016/j.colsurfa.2022.129809.
93. M. Elumalai, G. Nagaraj, J. Kasthuri, E. Vellaichamy and N. Rajendiran, Evaluation of Cytotoxic Activity against A549 Human Lung Cancer Cells Using Green Synthesized N-Cholyl D-Penicillamine Encapsulated Silver and Gold Nanoparticles, Inorg. Chem. Commun., 2023, 153, 110834,  DOI:10.1016/j.inoche.2023.110834.
94. A. B. Thakkar, R. B. Subramanian, V. R. Thakkar, S. V. Bhatt, S. Chaki, Y. H. Vaidya, V. Patel and P. Thakor, Apoptosis Induction Capability of Silver Nanoparticles Capped with Acorus Calamus L. and Dalbergia Sissoo Roxb. Ex DC. against Lung Carcinoma Cells, Heliyon, 2024, 10(2), e24400,  DOI:10.1016/j.heliyon.2024.e24400.
95. R. Misra, S. Hazra, S. Saleem and S. Nehru, Drug-Loaded Polymer-Coated Silver Nanoparticles for Lung Cancer Theranostics, Med. Oncol., 2024, 41(6), 132,  DOI:10.1007/s12032-024-02372-y.
96. A. Raj, R. K. Thomas, L. Vidya, V. M. Aparna, S. Neelima and C. Sudarsanakumar, Exploring the Cytotoxicity on Human Lung Cancer Cells and DNA Binding Stratagem of Camptothecin Functionalised Silver Nanoparticles through Multi-Spectroscopic, and Calorimetric Approach, Sci. Rep., 2023, 13(1), 9045,  DOI:10.1038/s41598-023-34997-w.
97. D. Sivalingam and M. Singh, Polymeric Silver Nanoparticles for ACE2-Receptor Targeting to Lung Cancer Cells in Vitro, Biointerface Res. Appl. Chem., 2024, 14(3), 68,  DOI:10.33263/BRIAC143.068.
98. G. Kah, R. Chandran and H. Abrahamse, Green Silver Nanoparticles Curcumin Conjugate Induced Photodynamic Therapy of Lung Cancer and Lung Cancer Stem Cells, RSC Adv., 2025, 15(7), 5020–5041,  10.1039/D4RA06035K.
99. J. S. Patton and P. R. Byron, Inhaling Medicines: Delivering Drugs to the Body through the Lungs, Nat. Rev. Drug Discovery, 2007, 6(1), 67–74,  DOI:10.1038/nrd2153.
100. N. R. Labiris and M. B. Dolovich, Pulmonary Drug Delivery. Part I: Physiological Factors Affecting Therapeutic Effectiveness of Aerosolized Medications, Br. J. Clin. Pharmacol., 2003, 56(6), 588–599,  DOI:10.1046/j.1365-2125.2003.01892.x.
101. E. Blanco, H. Shen and M. Ferrari, Principles of Nanoparticle Design for Overcoming Biological Barriers to Drug Delivery, Nat. Biotechnol., 2015, 33(9), 941–951,  DOI:10.1038/nbt.3330.
102. J. Shi, P. W. Kantoff, R. Wooster and O. C. Farokhzad, Cancer Nanomedicine: Progress, Challenges and Opportunities, Nat. Rev. Cancer, 2017, 17(1), 20–37,  DOI:10.1038/nrc.2016.108.
103. A. C. Anselmo and S. Mitragotri, Nanoparticles in the Clinic, Bioeng. Transl. Med., 2016, 1(1), 10–29,  DOI:10.1002/btm2.10003.
104. Y. He, Z. Du, S. Ma, Y. Liu, D. Li, H. Huang, S. Jiang, S. Cheng, W. Wu, K. Zhang and X. Zheng, Effects of Green-Synthesized Silver Nanoparticles on Lung Cancer Cells in Vitro and Grown as Xenograft Tumors in Vivo, Int. J. Nanomed., 2016, 1879,  DOI:10.2147/IJN.S103695.
105. H. Guo, J. Zhang, M. Boudreau, J. Meng, J. Yin, J. Liu and H. Xu, Intravenous Administration of Silver Nanoparticles Causes Organ Toxicity through Intracellular ROS-Related Loss of Inter-Endothelial Junction, Part. Fibre Toxicol., 2015, 13(1), 21,  DOI:10.1186/s12989-016-0133-9.
106. A. Sargsian, X. Koutsoumpou, H. Girmatsion, C. Egil, K. Buttiens, C. R. Luci, S. J. Soenen and B. B. Manshian, Silver Nanoparticle Induced Immunogenic Cell Death Can Improve Immunotherapy, J. Nanobiotechnol., 2024, 22(1), 691,  DOI:10.1186/s12951-024-02951-1.
107. H. Lee, K. Sajid and J. Lee, Engineered Nanocarriers for Targeted Lung Cancer Therapy: Mechanistic Innovations and Recent Clinical Progress, Explor. Targeted Antitumor Ther., 2025, 6, 1002339,  DOI:10.37349/etat.2025.1002339.
108. L. Xie, D. Xie, Z. Du, S. Xue, K. Wang, X. Yu, X. Liu, Q. Peng and C. Fang, A Novel Therapeutic Outlook: Classification, Applications and Challenges of Inhalable Micron/Nanoparticle Drug Delivery Systems in Lung Cancer (Review, Int. J. Oncol., 2024, 64(4), 38,  DOI:10.3892/ijo.2024.5626.
109. A. Zamborlin, M. L. Ermini, M. Summa, G. Giannone, V. Frusca, A. K. Mapanao, D. Debellis, R. Bertorelli and V. Voliani, The Fate of Intranasally Instilled Silver Nanoarchitectures, Nano Lett., 2022, 22(13), 5269–5276,  DOI:10.1021/acs.nanolett.2c01180.
110. Y. He, Z. Du, S. Ma, Y. Liu, D. Li, H. Huang, S. Jiang, S. Cheng, W. Wu, K. Zhang and X. Zheng, Effects of Green-Synthesized Silver Nanoparticles on Lung Cancer Cells in Vitro and Grown as Xenograft Tumors in Vivo, Int. J. Nanomed., 2016, 1879,  DOI:10.2147/IJN.S103695.
111. A. M. Hongal, A. K. Shettar, J. H. Hoskeri and A. B. Vedamurthy, Silver Nanoparticles Mediated Apoptosis and Cell Cycle Arrest in Lung Cancer A549, 3 Biotech, 2024, 14(10), 238,  DOI:10.1007/s13205-024-04064-w.
112. R. Govender, A. Phulukdaree, R. M. Gengan, K. Anand and A. A. Chuturgoon, Silver Nanoparticles of Albizia Adianthifolia: The Induction of Apoptosis in Human Lung Carcinoma Cell Line, J. Nanobiotechnol., 2013, 11(1), 5,  DOI:10.1186/1477-3155-11-5.
113. T. Muthu, R. Adusumalli, S. K. Vemuri, M. Indira Devi, P. Pavan Kumar, R. R. Banala and A. V. Gurava Reddy, Eco-Biofabrication of Silver Nanoparticles from Azadirachta Indica, Gymnema Sylvestre, and Moringa Oleifera for Lung Cancer Treatment, J. Egypt. Natl. Cancer Inst., 2025, 37(1), 1,  DOI:10.1186/s43046-024-00252-0.
114. A. R. Gliga, S. Skoglund, I. Odnevall Wallinder, B. Fadeel and H. L. Karlsson, Size-Dependent Cytotoxicity of Silver Nanoparticles in Human Lung Cells: The Role of Cellular Uptake, Agglomeration and Ag Release, Part. Fibre Toxicol., 2014, 11(1), 11,  DOI:10.1186/1743-8977-11-11.
115. M. Sousa De Almeida, E. Susnik, B. Drasler, P. Taladriz-Blanco, A. Petri-Fink and B. Rothen-Rutishauser, Understanding Nanoparticle Endocytosis to Improve Targeting Strategies in Nanomedicine, Chem. Soc. Rev., 2021, 50(9), 5397–5434,  10.1039/d0cs01127d.
116. Y. Peng, Z. Yang, H. Sun, J. Li, X. Lan and S. Liu, Nanomaterials in Medicine: Understanding Cellular Uptake, Localization, and Retention for Enhanced Disease Diagnosis and Therapy, Aging Dis., 2024, 16(1), 168–208,  DOI:10.14336/AD.2024.0206-1.
117. Z. Yu, J. Zou and F. Xu, Tumor-Associated Macrophages Affect the Treatment of Lung Cancer, Heliyon, 2024, 10(7), e29332,  DOI:10.1016/j.heliyon.2024.e29332.
118. I. V. Zelepukin, K. G. Shevchenko and S. M. Deyev, Rediscovery of Mononuclear Phagocyte System Blockade for Nanoparticle Drug Delivery, Nat. Commun., 2024, 15(1), 4366,  DOI:10.1038/s41467-024-48838-5.
119. H.-J. Lee, Y. Woo, T.-W. Hahn, Y. M. Jung and Y.-J. Jung, Formation and Maturation of the Phagosome: A Key Mechanism in Innate Immunity against Intracellular Bacterial Infection, Microorganisms, 2020, 8(9), 1298,  DOI:10.3390/microorganisms8091298.
120. S. Behzadi, V. Serpooshan, W. Tao, M. A. Hamaly, M. Y. Alkawareek, E. C. Dreaden, D. Brown, A. M. Alkilany, O. C. Farokhzad and M. Mahmoudi, Cellular Uptake of Nanoparticles: Journey Inside the Cell, Chem. Soc. Rev., 2017, 46(14), 4218–4244,  10.1039/c6cs00636a.
121. S. Bournazos, A. Gupta and J. V. Ravetch, The Role of IgG Fc Receptors in Antibody-Dependent Enhancement, Nat. Rev. Immunol., 2020, 20(10), 633–643,  DOI:10.1038/s41577-020-00410-0.
122. S.-Y. Li, Y.-L. Guo, J.-W. Tian, H.-J. Zhang, R.-F. Li, P. Gong and Z.-L. Yu, Anti-Tumor Strategies by Harnessing the Phagocytosis of Macrophages, Cancers, 2023, 15(10), 2717,  DOI:10.3390/cancers15102717.
123. D. Cai, W. Gao, Z. Li, Y. Zhang, L. Xiao and Y. Xiao, Current Development of Nano-Drug Delivery to Target Macrophages, Biomedicines, 2022, 10(5), 1203,  DOI:10.3390/biomedicines10051203.
124. D. J. Rioux and D. C. Prosser, A CIE Change in Our Understanding of Endocytic Mechanisms, Front. Cell Dev. Biol., 2023, 11 DOI:10.3389/fcell.2023.1334798.
125. D. Ivanova and M. A. Cousin, Synaptic Vesicle Recycling and the Endolysosomal System: A Reappraisal of Form and Function, Front. Synaptic Neurosci., 2022, 14 DOI:10.3389/fnsyn.2022.826098.
126. M. Kuijpers, D. Azarnia Tehran, V. Haucke and T. Soykan, The Axonal Endolysosomal and Autophagic Systems, J. Neurochem., 2021, 158(3), 589–602,  DOI:10.1111/jnc.15287.
127. D. Manzanares and V. Ceña, Endocytosis: The Nanoparticle and Submicron Nanocompounds Gateway into the Cell, Pharmaceutics, 2020, 12(4), 371,  DOI:10.3390/pharmaceutics12040371.
128. D. A. Kuhn, D. Vanhecke, B. Michen, F. Blank, P. Gehr, A. Petri-Fink and B. Rothen-Rutishauser, Different Endocytotic Uptake Mechanisms for Nanoparticles in Epithelial Cells and Macrophages, Beilstein J. Nanotechnol., 2014, 5, 1625–1636,  DOI:10.3762/bjnano.5.174.
129. R. G. Parton, M. A. Del Pozo, S. Vassilopoulos, I. R. Nabi, S. Le Lay, R. Lundmark, A. K. Kenworthy, A. Camus, C. M. Blouin, W. C. Sessa and C. Lamaze, Caveolae: The FAQs, Traffic, 2020, 21(1), 181–185,  DOI:10.1111/tra.12689.
130. D. Barman and R. Drolia, Caveolin-Mediated Endocytosis: Bacterial Pathogen Exploitation and Host–Pathogen Interaction, Cells, 2024, 14(1), 2,  DOI:10.3390/cells14010002.
131. C. Máthé, M. M-Hamvas, C. Freytag and T. Garda, The Protein Phosphatase PP2A Plays Multiple Roles in Plant Development by Regulation of Vesicle Traffic—Facts and Questions, Int. J. Mol. Sci., 2021, 22(2), 975,  DOI:10.3390/ijms22020975.
132. E. Larsson; B. Morén; K.-A. McMahon; R. G. Parton and R. Lundmark, Dynamin2 Stabilizes Plasma Membrane-Connected Caveolae by Restraining Fission, Cold Spring Harbor Laboratory, 2022, vol. 25 DOI:10.1101/2022.05.25.493372.
133. B. R. Ramazanov, M. L. Tran and J. Von Blume, Sending out Molecules from the TGN, Curr. Opin. Cell Biol., 2021, 71, 55–62,  DOI:10.1016/j.ceb.2021.02.005.
134. L. Li, X. Wu, Q. Guo, Y. Wang, Z. He, G. Zhang, S. Liu, L. Shu, B. Gajendran, Y. Chen, X. Shen and L. Tao, Effect of Cholesterol on Distribution, Cell Uptake, and Protein Corona of Lipid Microspheres at Sites of Cardiovascular Inflammatory Injury, J. Pharm. Anal., 2025, 15(7), 101182,  DOI:10.1016/j.jpha.2024.101182.
135. J. A. Swanson and J. S. King, The Breadth of Macropinocytosis Research, Philos. Trans. R. Soc., B, 2019, 374(1765), 20180146,  DOI:10.1098/rstb.2018.0146.
136. Z. Budai, L. Ujlaky-Nagy, G. N. Kis, M. Antal, C. Bankó, Z. Bacsó, Z. Szondy and Z. Sarang, Macrophages Engulf Apoptotic and Primary Necrotic Thymocytes through Similar Phosphatidylserine-dependent Mechanisms, FEBS Open Bio, 2019, 9(3), 446–456,  DOI:10.1002/2211-5463.12584.
137. C. M. Buckley and J. S. King, Drinking Problems: Mechanisms of Macropinosome Formation and Maturation, FEBS J., 2017, 284(22), 3778–3790,  DOI:10.1111/febs.14115.
138. E. M. Selwan, B. T. Finicle, S. M. Kim and A. L. Edinger, Attacking the Supply Wagons to Starve Cancer Cells to Death, FEBS Lett., 2016, 590(7), 885–907,  DOI:10.1002/1873-3468.12121.
139. O. K. Szewczyk-Roszczenko, P. Roszczenko, A. Shmakova, N. Finiuk, S. Holota, R. Lesyk, A. Bielawska, Y. Vassetzky and K. Bielawski, The Chemical Inhibitors of Endocytosis: From Mechanisms to Potential Clinical Applications, Cells, 2023, 12(18), 2312,  DOI:10.3390/cells12182312.
140. Z. Qiu, W. Liu, Q. Zhu, K. Ke, Q. Zhu, W. Jin, S. Yu, Z. Yang, L. Li, X. Sun, S. Ren, Y. Liu, Z. Zhu, J. Zeng, X. Huang, Y. Huang, L. Wei, M. Ma, J. Lu, X. Chen, Y. Mou, T. Xie and X. Sui, The Role and Therapeutic Potential of Macropinocytosis in Cancer, Front. Pharmacol., 2022, 13, 919819,  DOI:10.3389/fphar.2022.919819.
141. K. Kaladharan, A. Kumar, P. Gupta, K. Illath, T. Santra and F.-G. Tseng, Microfluidic Based Physical Approaches towards Single-Cell Intracellular Delivery and Analysis, Micromachines, 2021, 12(6), 631,  DOI:10.3390/mi12060631.
142. F. Kurul, H. Turkmen, A. E. Cetin and S. N. Topkaya, Nanomedicine: How Nanomaterials Are Transforming Drug Delivery, Bio-Imaging, and Diagnosis, Next Nanotechnol., 2025, 7, 100129,  DOI:10.1016/j.nxnano.2024.100129.
143. S. Daum, H. Hagen, E. Naismith, D. Wolf and A. Pircher, The Role of Anti-Angiogenesis in the Treatment Landscape of Non-Small Cell Lung Cancer – New Combinational Approaches and Strategies of Neovessel Inhibition, Front. Cell Dev. Biol., 2021, 8, 610903,  DOI:10.3389/fcell.2020.610903.
144. M. Zhang, S. Gao, D. Yang, Y. Fang, X. Lin, X. Jin, Y. Liu, X. Liu, K. Su and K. Shi, Influencing Factors and Strategies of Enhancing Nanoparticles into Tumors in Vivo, Acta Pharm. Sin. B, 2021, 11(8), 2265–2285,  DOI:10.1016/j.apsb.2021.03.033.
145. R. J. Holmila, S. A. Vance, S. B. King, A. W. Tsang, R. Singh and C. M. Furdui, Silver Nanoparticles Induce Mitochondrial Protein Oxidation in Lung Cells Impacting Cell Cycle and Proliferation, Antioxidants, 2019, 8(11), 552,  DOI:10.3390/antiox8110552.
146. T. Miyayama and M. Matsuoka, Involvement of Lysosomal Dysfunction in Silver Nanoparticle-Induced Cellular Damage in A549 Human Lung Alveolar Epithelial Cells, J. Occup. Med. Toxicol., 2016, 11, 1,  DOI:10.1186/s12995-016-0090-0.
147. D. Wu, A. Dasgupta, A. D. Read, R. E. T. Bentley, M. Motamed, K.-H. Chen, R. Al-Qazazi, J. D. Mewburn, K. J. Dunham-Snary, E. Alizadeh, L. Tian and S. L. Archer, Oxygen Sensing, Mitochondrial Biology and Experimental Therapeutics for Pulmonary Hypertension and Cancer, Free Radicals Biol. Med., 2021, 170, 150–178,  DOI:10.1016/j.freeradbiomed.2020.12.452.
148. M. Akter, Md. T. Sikder, Md. M. Rahman, A. K. M. A. Ullah, K. F. B. Hossain, S. Banik, T. Hosokawa, T. Saito and M. Kurasaki, A Systematic Review on Silver Nanoparticles-Induced Cytotoxicity: Physicochemical Properties and Perspectives, J. Adv. Res., 2018, 9, 1–16,  DOI:10.1016/j.jare.2017.10.008.
149. E. Austria, M. Bilek, P. Varamini and B. Akhavan, Breaking Biological Barriers: Engineering Polymeric Nanoparticles for Cancer Therapy, Nano Today, 2025, 60, 102552,  DOI:10.1016/j.nantod.2024.102552.
150. C. Pegoraro, I. Domingo-Ortí, I. Conejos-Sánchez and M. J. Vicent, Unlocking the Mitochondria for Nanomedicine-Based Treatments: Overcoming Biological Barriers, Improving Designs, and Selecting Verification Techniques, Adv. Drug Delivery Rev., 2024, 207, 115195,  DOI:10.1016/j.addr.2024.115195.
151. B.-H. Mao, J.-C. Tsai, C.-W. Chen, S.-J. Yan and Y.-J. Wang, Mechanisms of Silver Nanoparticle-Induced Toxicity and Important Role of Autophagy, Nanotoxicology, 2016, 10(8), 1021–1040,  DOI:10.1080/17435390.2016.1189614.
152. R. Kumari, A. K. Saini, A. Kumar and R. V. Saini, Apoptosis Induction in Lung and Prostate Cancer Cells through Silver Nanoparticles Synthesized from Pinus Roxburghii Bioactive Fraction, J. Biol. Inorg. Chem., 2020, 25(1), 23–37,  DOI:10.1007/s00775-019-01729-3.
153. G. Raja, Y.-K. Jang, J.-S. Suh, H.-S. Kim, S. H. Ahn and T.-J. Kim, Microcellular Environmental Regulation of Silver Nanoparticles in Cancer Therapy: A Critical Review, Cancers, 2020, 12(3), 664,  DOI:10.3390/cancers12030664.
154. J. L. Mejía-Méndez, E. R. López-Mena and E. Sánchez-Arreola, Activities against Lung Cancer of Biosynthesized Silver Nanoparticles: A Review, Biomedicines, 2023, 11(2), 389,  DOI:10.3390/biomedicines11020389.
155. J. He, Y. Ma, X. Niu, J. Pei, R. Yan, F. Xu, J. Ma, X. Ma, S. Jia and W. Ma, Silver Nanoparticles Induce Endothelial Cytotoxicity through ROS-Mediated Mitochondria-Lysosome Damage and Autophagy Perturbation: The Protective Role of N-Acetylcysteine, Toxicology, 2024, 502, 153734,  DOI:10.1016/j.tox.2024.153734.
156. S. Fallah, E. Yusefi-Tanha and J. R. Peralta-Videa, Interaction of Nanoparticles and Reactive Oxygen Species and Their Impact on Macromolecules and Plant Production, Plant Nano Biol., 2024, 10, 100105,  DOI:10.1016/j.plana.2024.100105.
157. C. Guo, A. Buckley, T. Marczylo, J. Seiffert, I. Römer, J. Warren, A. Hodgson, K. F. Chung, T. W. Gant, R. Smith and M. O. Leonard, The Small Airway Epithelium as a Target for the Adverse Pulmonary Effects of Silver Nanoparticle Inhalation, Nanotoxicology, 2018, 12(6), 539–553,  DOI:10.1080/17435390.2018.1465140.
158. S. J. Cameron, F. Hosseinian and W. G. Willmore, A Current Overview of the Biological and Cellular Effects of Nanosilver, Int. J. Mol. Sci., 2018, 19(7), 2030,  DOI:10.3390/ijms19072030.
159. L. A. Sena and N. S. Chandel, Physiological Roles of Mitochondrial Reactive Oxygen Species, Mol. Cell, 2012, 48(2), 158–167,  DOI:10.1016/j.molcel.2012.09.025.
160. H. Wu, J. Lin, P. Liu, Z. Huang, P. Zhao, H. Jin, J. Ma, L. Wen and N. Gu, Reactive Oxygen Species Acts as Executor in Radiation Enhancement and Autophagy Inducing by AgNPs, Biomaterials, 2016, 101, 1–9,  DOI:10.1016/j.biomaterials.2016.05.031.
161. P. C. Rao, S. Begum, M. Sahai and D. S. Sriram, Coptisine-Induced Cell Cycle Arrest at G2/M Phase and Reactive Oxygen Species–Dependent Mitochondria-Mediated Apoptosis in Non-Small-Cell Lung Cancer A549 Cells, Tumour Biol., 2017, 39(3), 101042831769456,  DOI:10.1177/1010428317694565.
162. K. Kawamura, F. Qi and J. Kobayashi, Potential Relationship between the Biological Effects of Low-Dose Irradiation and Mitochondrial ROS Production, J. Radiat. Res., 2018, 59(suppl_2), ii91–ii97,  DOI:10.1093/jrr/rrx091.
163. W. Ma, L. Jing, A. Valladares, S. L. Mehta, Z. Wang, P. A. Li and J. J. Bang, Silver Nanoparticle Exposure Induced Mitochondrial Stress, Caspase-3 Activation and Cell Death: Amelioration by Sodium Selenite, Int. J. Biol. Sci., 2015, 11(8), 860–867,  DOI:10.7150/ijbs.12059.
164. R. J. Holmila, S. A. Vance, S. B. King, A. W. Tsang, R. Singh and C. M. Furdui, Silver Nanoparticles Induce Mitochondrial Protein Oxidation in Lung Cells Impacting Cell Cycle and Proliferation, Antioxidants, 2019, 8(11), 552,  DOI:10.3390/antiox8110552.
165. Z. V. Arsenopoulou, I. A. Taitzoglou, P.-A. Molyvdas, K. I. Gourgoulianis, C. Hatzoglou and S. G. Zarogiannis, Silver Nanoparticles Alter the Permeability of Sheep Pleura and of Sheep and Human Pleural Mesothelial Cell Monolayers, Environ. Toxicol. Pharmacol., 2017, 50, 212–215,  DOI:10.1016/j.etap.2017.02.009.
166. Y. Wāng, Y. Han and D.-X. Xu, Developmental Impacts and Toxicological Hallmarks of Silver Nanoparticles across Diverse Biological Models, Environ. Sci. Ecotechnology, 2024, 19, 100325,  DOI:10.1016/j.ese.2023.100325.
167. V. Bastos, I. F. Duarte, C. Santos and H. Oliveira, Genotoxicity of Citrate-Coated Silver Nanoparticles to Human Keratinocytes Assessed by the Comet Assay and Cytokinesis Blocked Micronucleus Assay, Environ. Sci. Pollut. Res., 2017, 24(5), 5039–5048,  DOI:10.1007/s11356-016-8240-6.
168. F. Rosário, P. Hoet, C. Santos and H. Oliveira, Death and Cell Cycle Progression Are Differently Conditioned by the AgNP Size in Osteoblast-like Cells, Toxicology, 2016, 368–369, 103–115,  DOI:10.1016/j.tox.2016.08.020.
169. P. Takáč, R. Michalková, M. Čižmáriková, Z. Bedlovičová, Ľ. Balážová and G. Takáčová, The Role of Silver Nanoparticles in the Diagnosis and Treatment of Cancer: Are There Any Perspectives for the Future, Life, 2023, 13(2), 466,  DOI:10.3390/life13020466.
170. J. Mytych, J. Zebrowski, A. Lewinska and M. Wnuk, Prolonged Effects of Silver Nanoparticles on P53/P21 Pathway-Mediated Proliferation, DNA Damage Response, and Methylation Parameters in HT22 Hippocampal Neuronal Cells, Mol. Neurobiol., 2017, 54(2), 1285–1300,  DOI:10.1007/s12035-016-9688-6.
171. J. Chen, The Cell-Cycle Arrest and Apoptotic Functions of P53 in Tumor Initiation and Progression, Cold Spring Harbor Perspect. Med., 2016, 6(3), a026104,  DOI:10.1101/cshperspect.a026104.
172. S. Khazaei, N. M. Esa, V. Ramachandran, R. A. Hamid, A. K. Pandurangan, A. Etemad and P. Ismail, In Vitro Antiproliferative and Apoptosis Inducing Effect of Allium Atroviolaceum Bulb Extract on Breast, Cervical, and Liver Cancer Cells, Front. Pharmacol., 2017, 8 DOI:10.3389/fphar.2017.00005.
173. J.-K. Jeong, S. Gurunathan, M.-H. Kang, J. W. Han, J. Das, Y.-J. Choi, D.-N. Kwon, S.-G. Cho, C. Park, H. G. Seo, H. Song and J.-H. Kim, Hypoxia-Mediated Autophagic Flux Inhibits Silver Nanoparticle-Triggered Apoptosis in Human Lung Cancer Cells, Sci. Rep., 2016, 6(1), 21688,  DOI:10.1038/srep21688.
174. L. Li, L. Li, X. Zhou, Y. Yu, Z. Li, D. Zuo and Y. Wu, Silver Nanoparticles Induce Protective Autophagy via Ca²⁺/CaMKKβ/AMPK/mTOR Pathway in SH-SY5Y Cells and Rat Brains, Nanotoxicology, 2019, 13(3), 369–391,  DOI:10.1080/17435390.2018.1550226.
175. W. A. Hailan, K. M. Al-Anazi, M. A. Farah, M. A. Ali, A. A. Al-Kawmani and F. M. Abou-Tarboush, Reactive Oxygen Species-Mediated Cytotoxicity in Liver Carcinoma Cells Induced by Silver Nanoparticles Biosynthesized Using Schinus Molle Extract, Nanomaterials, 2022, 12(1), 161,  DOI:10.3390/nano12010161.
176. M. Su, Y. Mei and S. Sinha, Role of the Crosstalk between Autophagy and Apoptosis in Cancer, J. Oncol., 2013, 2013, 1–14,  DOI:10.1155/2013/102735.
177. J. Kim, M. Kundu, B. Viollet and K.-L. Guan, AMPK and mTOR Regulate Autophagy through Direct Phosphorylation of Ulk1, Nat. Cell Biol., 2011, 13(2), 132–141,  DOI:10.1038/ncb2152.
178. Y. Chen, T. Yang, S. Chen, S. Qi, Z. Zhang and Y. Xu, Silver Nanoparticles Regulate Autophagy through Lysosome Injury and Cell Hypoxia in Prostate Cancer Cells, J. Biochem. Mol. Toxicol., 2020, 34(5), e22474,  DOI:10.1002/jbt.22474.
179. L. Bobyk, A. Tarantini, D. Beal, G. Veronesi, I. Kieffer, S. Motellier, E. Valsami-Jones, I. Lynch, P.-H. Jouneau, K. Pernet-Gallay, C. Aude-Garcia, S. Sauvaigo, T. Douki, T. Rabilloud and M. Carriere, Toxicity and Chemical Transformation of Silver Nanoparticles in A549 Lung Cells: Dose-Rate-Dependent Genotoxic Impact, Environ. Sci.: Nano, 2021, 8(3), 806–821,  10.1039/d0en00533a.
180. Y. Huang, R. Chen, Y. Chen and X. Lü, Investigation of Molecular Mechanisms in Silver Nanoparticle-Induced Cytotoxicity from Gene to Metabolite Level, Sci. Rep., 2025, 15(1), 26923,  DOI:10.1038/s41598-025-12477-7.
181. M. Abdelgwad, D. Sabry, L. Mohamed Abdelgawad and D. Mohamed Elroby Ali, In Vitro Differential Sensitivity of Head and Neck Squamous Cell Carcinoma to Cisplatin, Silver Nanoparticles, and Photodynamic Therapy, Rep. Biochem. Mol. Biol., 2022, 11, 224–237,  DOI:10.52547/rbmb.11.2.224.
182. S. R. Kabir, F. Islam and A. K. M. Asaduzzaman, Biogenic Silver/Silver Chloride Nanoparticles Inhibit Human Cancer Cells Proliferation in Vitro and Ehrlich Ascites Carcinoma Cells Growth in Vivo, Sci. Rep., 2022, 12(1), 8909,  DOI:10.1038/s41598-022-12974-z.
183. A. Tarar and C.-A. Peng, Antineoplastic Potency of Sinigrin-Functionalized Silver Nanoparticles on Tumor Cells Transfected with Myrosinase-Encoded Plasmids, BioNanoSci, 2024, 14(1), 81–92,  DOI:10.1007/s12668-023-01233-8.
184. Y.-G. Yuan, S. Zhang, J.-Y. Hwang and I.-K. Kong, Silver Nanoparticles Potentiates Cytotoxicity and Apoptotic Potential of Camptothecin in Human Cervical Cancer Cells, Oxid. Med. Cell. Longevity, 2018, 2018(1), 6121328,  DOI:10.1155/2018/6121328.
185. W. Liu, J. Su, Q. Shi, J. Wang, X. Chen, S. Zhang, M. Li, J. Cui, C. Fan, B. Sun and G. Wang, RGD Peptide-Conjugated Selenium Nanocomposite Inhibits Human Glioma Growth by Triggering Mitochondrial Dysfunction and ROS-Dependent MAPKs Activation, Front. Bioeng. Biotechnol., 2021, 9, 781608,  DOI:10.3389/fbioe.2021.781608.
186. R. Sugiura, R. Satoh and T. Takasaki, ERK: A Double-Edged Sword in Cancer. ERK-Dependent Apoptosis as a Potential Therapeutic Strategy for Cancer, Cells, 2021, 10(10), 2509,  DOI:10.3390/cells10102509.
187. X. Zhao, T. Qi, C. Kong, M. Hao, Y. Wang, J. Li, B. Liu, Y. Gao and J. Jiang, Photothermal Exposure of Polydopamine-Coated Branched Au–Ag Nanoparticles Induces Cell Cycle Arrest, Apoptosis, and Autophagy in Human Bladder Cancer Cells, Int. J. Nanomed., 2018, 13, 6413–6428,  DOI:10.2147/IJN.S174349.
188. C. G. Kim, V. Castro-Aceituno, R. Abbai, H. A. Lee, S. Y. Simu, Y. Han, J. Hurh, Y.-J. Kim and D. C. Yang, Caspase-3/MAPK Pathways as Main Regulators of the Apoptotic Effect of the Phyto-Mediated Synthesized Silver Nanoparticle from Dried Stem of Eleutherococcus Senticosus in Human Cancer Cells, Biomed. Pharmacother., 2018, 99, 128–133,  DOI:10.1016/j.biopha.2018.01.050.
189. X.-F. Zhang, W. Shen and S. Gurunathan, Silver Nanoparticle-Mediated Cellular Responses in Various Cell Lines: An in Vitro Model, Int. J. Mol. Sci., 2016, 17(10), 1603,  DOI:10.3390/ijms17101603.
190. H. K. Lim, R. L. Gurung and M. P. Hande, DNA-Dependent Protein Kinase Modulates the Anti-Cancer Properties of Silver Nanoparticles in Human Cancer Cells, Mutat. Res., Genet. Toxicol. Environ. Mutagen., 2017, 824, 32–41,  DOI:10.1016/j.mrgentox.2017.10.001.
191. C. Liao, Y. Li and S. C. Tjong, Bactericidal and Cytotoxic Properties of Silver Nanoparticles, Int. J. Mol. Sci., 2019, 20(2), 449,  DOI:10.3390/ijms20020449.
192. J. G. González-Vega, J. C. García-Ramos, R. A. Chavez-Santoscoy, J. E. Castillo-Quiñones, M. E. Arellano-Garcia and Y. Toledano-Magaña, Lung Models to Evaluate Silver Nanoparticles’ Toxicity and Their Impact on Human Health, Nanomaterials, 2022, 12(13), 2316,  DOI:10.3390/nano12132316.
193. T. Miyayama and M. Matsuoka, Involvement of Lysosomal Dysfunction in Silver Nanoparticle-Induced Cellular Damage in A549 Human Lung Alveolar Epithelial Cells, J. Occup. Med. Toxicol., 2016, 11(1), 1,  DOI:10.1186/s12995-016-0090-0.
194. S. Gurunathan, M.-H. Kang, M. Qasim and J.-H. Kim, Nanoparticle-Mediated Combination Therapy: Two-in-One Approach for Cancer, Int. J. Mol. Sci., 2018, 19(10), 3264,  DOI:10.3390/ijms19103264.
195. M. Rozalen, M. Sánchez-Polo, M. Fernández-Perales, T. J. Widmann and J. Rivera-Utrilla, Synthesis of Controlled-Size Silver Nanoparticles for the Administration of Methotrexate Drug and Its Activity in Colon and Lung Cancer Cells, RSC Adv., 2020, 10(18), 10646–10660,  10.1039/C9RA08657A.
196. T. Tunç, C. Hepokur and A. Kari̇per, Synthesis and Characterization of Paclitaxel-Loaded Silver Nanoparticles: Evaluation of Cytotoxic Effects and Antimicrobial Activity, Bioinorg. Chem. Appl., 2024, 2024, 1–13,  DOI:10.1155/2024/9916187.
197. T. Tunç, Synthesis and Characterization of Silver Nanoparticles Loaded with Carboplatin as a Potential Antimicrobial and Cancer Therapy, Cancer Nano, 2024, 15(1), 2,  DOI:10.1186/s12645-023-00243-1.
198. H. Fayez, M. A. El-Motaleb and A. A. Selim, Synergistic Cytotoxicity Of Shikonin-Silver Nanoparticles As An Opportunity For Lung Cancer, Labelled Compd. Radiopharm., 2020, 63(1), 25–32,  DOI:10.1002/jlcr.3818.
199. I. Matai, A. Sachdev and P. Gopinath, Multicomponent 5-Fluorouracil Loaded PAMAM Stabilized-Silver Nanocomposites Synergistically Induce Apoptosis in Human Cancer Cells, Biomater. Sci., 2015, 3(3), 457–468,  10.1039/C4BM00360H.
200. J. Morey, P. Llinás, A. Bueno-Costa, A. J. León and M. N. Piña, Raltitrexed-Modified Gold and Silver Nanoparticles for Targeted Cancer Therapy: Cytotoxicity Behavior In Vitro on A549 and HCT-116 Human Cancer Cells, Materials, 2021, 14(3), 534,  DOI:10.3390/ma14030534.
201. A. Ullah, M. Saadullah, F. Alvi, L. Sherin, A. Ali, N. A. Shad, Y. Javed, M. M. Sajid, G. Yasin and W. Abbas, Synergistic Effect of Silver Doped ZnO Nanomaterials Enhances the Anticancer Potential against A459 Lung Cancer Cells, J. King Saud Univ., Sci., 2022, 34(1), 101724,  DOI:10.1016/j.jksus.2021.101724.
202. T. Goel, N. Deshwal, S. Gusain, R. Chandra, M. Tiwari and S. Singh, Synthesis, Characterisation of ZnO@PDA@Ag Nanocomposite: Mechanistic Interaction with BSA, Photodegradation Activity & in Vitro Cytotoxicity Assay on H1299 Lung Cancer Cell Line, Int. J. Biol. Macromol., 2024, 283, 137532,  DOI:10.1016/j.ijbiomac.2024.137532.
203. D. Reshmi Agnes Preethi, S. Prabhu, V. Ravikumar and A. Philominal, Anticancer Activity of Pure and Silver Doped Copper Oxide Nanoparticles against A549 Cell Line, Mater. Today Commun., 2022, 33, 104462,  DOI:10.1016/j.mtcomm.2022.104462.
204. S. Singh, T. Goel, A. Singh, H. Chugh, N. Chakraborty, I. Roy, M. Tiwari and R. Chandra, Synthesis and Characterization of Fe₃ O₄ @SiO₂ @PDA@Ag Core–Shell Nanoparticles and Biological Application on Human Lung Cancer Cell Line and Antibacterial Strains, Artif. Cells, Nanomed., Biotechnol., 2024, 52(1), 46–58,  DOI:10.1080/21691401.2023.2295534.
205. T. Huang, H. S. AlSalem, M. S. Binkadem, S. T. Al-Goul, A. F. El-kott, A. A. Alsayegh, G. J. Majdou, G. El-Saber Batiha and B. Karmakar, Green Synthesis of Ag/Fe₃O₄ Nanoparticles Using Mentha Extract: Preparation, Characterization and Investigation of Its Anti-Human Lung Cancer Application, J. Saudi Chem. Soc., 2022, 26(4), 101505,  DOI:10.1016/j.jscs.2022.101505.
206. Z. M. Alaizeri, H. A. Alhadlaq, S. Aldawood, M. J. Akhtar and M. Ahamed, Photodeposition Mediated Synthesis of Silver-Doped Indium Oxide Nanoparticles for Improved Photocatalytic and Anticancer Performance, Environ. Sci. Pollut. Res., 2023, 30(3), 6055–6067,  DOI:10.1007/s11356-022-22594-9.
207. D. B. Manikandan, M. Arumugam, A. Sridhar, B. Perumalsamy and T. Ramasamy, Sustainable Fabrication of Hybrid Silver-Copper Nanocomposites (Ag-CuO NCs) Using Ocimum Americanum L. as an Effective Regime against Antibacterial, Anticancer, Photocatalytic Dye Degradation and Microalgae Toxicity, Environ. Res., 2023, 228, 115867,  DOI:10.1016/j.envres.2023.115867.
208. J. Huang, J. Guo, J. Zhu and X. Zou, Supported Silver Nanoparticles over Alginate-Modified Magnetic Nanoparticles: Synthesis, Characterization and Treat the Human Lung Carcinoma, J. Saudi Chem. Soc., 2022, 26(1), 101393,  DOI:10.1016/j.jscs.2021.101393.
209. N. Asghari Moghaddam, A. Eskandari, B. Khodadadi, Y. Hafezi, J. K. Paduvilan and M. Tavakkoli Yaraki, Green Synthesis of Bimetallic AgZnO Nanoparticles: Synergistic Anticancer Effects through Regulation of Gene Expression for Lung Cancer Treatment, Results Eng., 2024, 22, 102329,  DOI:10.1016/j.rineng.2024.102329.
210. M. J. Nirmala, U. Kizhuveetil, A. Johnson, B. G, R. Nagarajan and V. Muthuvijayan, Cancer Nanomedicine: A Review of Nano-Therapeutics and Challenges Ahead, RSC Adv., 2023, 13(13), 8606–8629,  10.1039/D2RA07863E.
211. P. M. Giri, A. Banerjee and B. Layek, A Recent Review on Cancer Nanomedicine, Cancers, 2023, 15(8), 2256,  DOI:10.3390/cancers15082256.
212. M. Dias, R. Zhang, T. Lammers and R. M. Pallares, Clinical Translation and Landscape of Silver Nanoparticles, Drug Delivery Transl. Res., 2025, 15(3), 789–797,  DOI:10.1007/s13346-024-01716-5.
213. H. O. Khalifa, A. Oreiby, T. Mohammed, M. A. A. Abdelhamid, E. N. Sholkamy, H. Hashem and R. M. Fereig, Silver Nanoparticles as Next-Generation Antimicrobial Agents: Mechanisms, Challenges, and Innovations against Multidrug-Resistant Bacteria, Front. Cell. Infect. Microbiol., 2025, 15, 1599113,  DOI:10.3389/fcimb.2025.1599113.
214. J. Swanner, C. D. Fahrenholtz, I. Tenvooren, B. W. Bernish, J. J. Sears, A. Hooker, C. M. Furdui, E. Alli, W. Li, G. L. Donati, K. L. Cook, P. Vidi and R. Singh, Silver Nanoparticles Selectively Treat Triple-negative Breast Cancer Cells without Affecting Non-malignant Breast Epithelial Cells in Vitro and in Vivo, FASEB BioAdv., 2019, 1(10), 639–660,  DOI:10.1096/fba.2019-00021.
215. J. G. González-Vega, J. C. García-Ramos, R. A. Chavez-Santoscoy, J. E. Castillo-Quiñones, M. E. Arellano-Garcia and Y. Toledano-Magaña, Lung Models to Evaluate Silver Nanoparticles’ Toxicity and Their Impact on Human Health, Nanomaterials, 2022, 12(13), 2316,  DOI:10.3390/nano12132316.
216. J. Wang, T. Zhou, Y. Liu, S. Chen and Z. Yu, Application of Nanoparticles in the Treatment of Lung Cancer With Emphasis on Receptors, Front. Pharmacol., 2022, 12 DOI:10.3389/fphar.2021.781425.
217. A. Sharma, D. Shambhwani, S. Pandey, J. Singh, H. Lalhlenmawia, M. Kumarasamy, S. K. Singh, D. K. Chellappan, G. Gupta, P. Prasher, K. Dua and D. Kumar, Advances in Lung Cancer Treatment Using Nanomedicines, ACS Omega, 2023, 8(1), 10–41,  DOI:10.1021/acsomega.2c04078.
218. J. G. González-Vega, J. C. García-Ramos, R. A. Chavez-Santoscoy, J. E. Castillo-Quiñones, M. E. Arellano-Garcia and Y. Toledano-Magaña, Lung Models to Evaluate Silver Nanoparticles’ Toxicity and Their Impact on Human Health, Nanomaterials, 2022, 12(13), 2316,  DOI:10.3390/nano12132316.
219. N. Goshi, D. Lam, C. Bogguri, V. K. George, A. Sebastian, J. Cadena, N. F. Leon, N. R. Hum, D. R. Weilhammer, N. O. Fischer and H. A. Enright, Direct Effects of Prolonged TNF-α and IL-6 Exposure on Neural Activity in Human iPSC-Derived Neuron-Astrocyte Co-Cultures, Front. Cell. Neurosci., 2025, 19, 1512591,  DOI:10.3389/fncel.2025.1512591.
220. A. R. Gliga, S. Skoglund, I. Odnevall Wallinder, B. Fadeel and H. L. Karlsson, Size-Dependent Cytotoxicity of Silver Nanoparticles in Human Lung Cells: The Role of Cellular Uptake, Agglomeration and Ag Release, Part. Fibre Toxicol., 2014, 11(1), 11,  DOI:10.1186/1743-8977-11-11.
221. D. P. K. Lankveld, A. G. Oomen, P. Krystek, A. Neigh, A. Troost – De Jong, C. W. Noorlander, J. C. H. Van Eijkeren, R. E. Geertsma and W. H. De Jong, The Kinetics of the Tissue Distribution of Silver Nanoparticles of Different Sizes, Biomaterials, 2010, 31(32), 8350–8361,  DOI:10.1016/j.biomaterials.2010.07.045.
222. P. Takáč, R. Michalková, M. Čižmáriková, Z. Bedlovičová, Ľ. Balážová and G. Takáčová, The Role of Silver Nanoparticles in the Diagnosis and Treatment of Cancer: Are There Any Perspectives for the Future?, Life, 2023, 13(2), 466,  DOI:10.3390/life13020466.
223. B. Fadeel, L. Farcal, B. Hardy, S. Vázquez-Campos, D. Hristozov, A. Marcomini, I. Lynch, E. Valsami-Jones, H. Alenius and K. Savolainen, Advanced Tools for the Safety Assessment of Nanomaterials, Nat. Nanotechnol., 2018, 13(7), 537–543,  DOI:10.1038/s41565-018-0185-0.
224. L. J. Barkal, C. L. Procknow, Y. R. Álvarez-García, M. Niu, J. A. Jiménez-Torres, R. A. Brockman-Schneider, J. E. Gern, L. C. Denlinger, A. B. Theberge, N. P. Keller, E. Berthier and D. J. Beebe, Microbial Volatile Communication in Human Organotypic Lung Models, Nat. Commun., 2017, 8(1), 1770,  DOI:10.1038/s41467-017-01985-4.
225. S. Hua, M. B. C. De Matos, J. M. Metselaar and G. Storm, Current Trends and Challenges in the Clinical Translation of Nanoparticulate Nanomedicines: Pathways for Translational Development and Commercialization, Front. Pharmacol., 2018, 9, 790,  DOI:10.3389/fphar.2018.00790.
226. H. Young, Y. He, B. Joo, S. Ferguson, A. Demko, S. K. Butterfield, J. Lowe, N. F. Mjema, V. Sheth, L. Whitehead, M. J. Ruiz-Echevarria and S. Wilhelm, Toward the Scalable, Rapid, Reproducible, and Cost-Effective Synthesis of Personalized Nanomedicines at the Point of Care, Nano Lett., 2024, 24(3), 920–928,  DOI:10.1021/acs.nanolett.3c04171.
227. M. Dias, R. Zhang, T. Lammers and R. M. Pallares, Clinical Translation and Landscape of Silver Nanoparticles, Drug Delivery Transl. Res., 2025, 15(3), 789–797,  DOI:10.1007/s13346-024-01716-5.

---

Footnote

† Equal contribution: T. G. and D. J. contributed equally to this work.

---