Themed collection Journal of Materials Chemistry B Lunar New Year collection 2021

This review provides an overview of stimuli-responsive functional materials and their applications in soft robotics.

Exosomes have outstanding advantages as drug delivery carriers in the treatment of various diseases.

Owing to fascinating properties and biodegradability, opportunities and challenges of emerging black phosphorus (BP) and BP analogs (BPAs) in biomedical applications have been coexisted to study.

This review summarizes the recent advances of tumor microenvironment-activated NIR-II agents for tumor diagnosis and treatment, including smart NIR-II fluorescence imaging, photoacoustic imaging, photothermal therapy and photodynamic therapy.

Because of the environmental and economic casualties of biofouling on maritime navigation, modern studies have been devoted toward formulating advanced nanoscale composites in the controlled development of effective marine antifouling self-cleaning surfaces.

This review summarises recent advances in stretchable and tough conductive hydrogel sensors for wearable and implantable devices.

Gas-sensing applications commonly use nanomaterials (NMs) because of their unique physicochemical properties, including a high surface-to-volume ratio, enormous number of active sites, controllable morphology, and potential for miniaturisation.

Recent achievements and challenges in materials and manufacturing technologies of sensing electrodes in wearable biosensors have been highlighted.

Ratiometric fluorescence sensors that are achieved via the ratiometric fluorescence intensity changes of emission peaks based on multi-emission fluorescence probes show a huge advantage.

Increasing the electron withdrawing ability of substituents in monochlorinated BODIPY could vary the emission from the NIR-I to NIR-II region together with enhanced response rate, indicative of a promising approach for activatable NIR-II probes.

A gallol-functionalized polymer showed strong adhesion ability underwater. The effect of molecular weight and gallol content have been optimized resulting in the underwater adhesion strength as high as 4 MPa.

A glucose sensor based on a conductive Ni-MOF as an electrocatalyst exhibits a fast response time, low detection limit, and high sensitivity, and it can also be applied for the detection of glucose in blood serum samples.

An antibacterial hydrogel is developed through in situ formation of Ag nanoclusters on bacterial cellulous, which shows better and longer-lasting killing efficacy than that of pristine Ag NCs against both Gram-positive and Gram-negative bacteria.

A high-mechanical, ionic conductive and anti-freezing multi-crosslinked poly(vinyl alcohol) hydrogel was assembled as a multi-model, large range and wearable sensor.

The UA@Ti₃C₂ QDs with blue light emission were synthesized by a simple and green microwave-assisted method, and used as a sensitive and selective probe for the detection of TNP both on surfaces and in solution.

Nanoparticle-based phototherapy has evolved to include immunotherapy as an effective treatment combination for cancers through inducing anti-cancer immune activation leading to downstream adaptive responses and immune protection.

In order to improve the therapeutic efficacy and reduce the side effects of anticancer drugs, pH sensitive and biodegradable polyphosphazene prodrugs were prepared.

A skin-matched soft strain/pressure sensor fabricated by fully physically crosslinked conductive PDA–rGO/PVA hydrogel is reported for sensitive healthcare monitoring and human-machine interaction.

A benzothiazolium-based fluorescent pH probe HTBT2 with an ideal pK_a of 8.04 ± 0.02 for imaging mitochondrial pH in living cells.

Photodynamic therapy (PDT) and photothermal therapy (PTT) are well-developed light therapy methods for cancer; however, both have a few areas that need improvement.

Nanoparticles can internalize into cancer cells through CD44 and P-selectin ligand recognition, leading to significant enhancement of anti-prostate tumor activity.

A facile approach for the highly luminescent and biocompatible CsPbBr₃@SiO₂ core–shell PNCs was developed. The dual biological roles of these PNCs are demonstrated, offering new directions to the stable PNCs for a variety of biomedical applications.

One-dimensional trough-like Au–Ag₂S nano-hybrids with Ag₂S/Au/Ag₂S core/shell-like walls are chemically transformed from interfacial Ag nanowires and successfully used, under visible light, for the photoelectric detection of human α-thrombin.

Precisely controlled local ion-coordination and crosslinking generate diverse hydrogel devices with a reversible shape memory effect and rapid actuation in air.

In this study, the paracrine effect between adipose-derived mesenchymal stem cells (ADSCs) and osteoblasts was investigated in collagen-based three-dimensional (3D) scaffolds.

A 2D Fe-BTC nanosheet was prepared via a cation exchange route. Its peroxidase-like activity is 2.2 times that of 3D MIL-100(Fe) due to highly accessible surface active sites. This is helpful for substrate contact with the catalyst during the catalytic reaction.

The starch which is modified by catechol can form hydrogel in situ so that seal the wound and reduce bleeding.

A mussel-inspired catechol-based strategy has been widely used in the development of underwater adhesives.

A new multi-modal therapy agent FePt/BP–PEI–FA NCs, with FePt nanoparticles (FePt NPs) loaded onto ultrathin black phosphorus nanosheets (BPNs), has been constructed to enhance synergistic PTT, PDT and CDT that target primary tumors.

A fluorophore–protein complex for the visualization of mitochondria and the mouse intestine was developed. The complex formation of a naphthalene-based dipolar dye and serum albumin was identified and its imaging applications were investigated.

Herein, two AIE probes (BTD-1 and BTD-2) were designed and synthesized based on benzothiazole derivatives which could be used to track and image trace hypochlorite in mitochondria of Hela cell and zebrafish.

We reported a series of POSS-based antioxidant shape amphiphiles for preventing cell oxidative damage and promoting wound healing.

Phosphate-responsive peroxidase-mimicking two-dimensional-metal–organic-framework nanozymes were employed to develop alkaline phosphatase assays with tunable dynamic ranges and colorimetric logic gates.

Theranostic nanoparticles composed of amphiphilic paramagnetic polymers are assembled for dual mode imaging and synergistic therapy.

An anti-infective TA/hydrogel with non-swelling and adhesion properties could close wounds in a non-invasive way.

As traditional cancer treatment methods, photodynamic therapy (PDT) and photothermal therapy (PTT) can eliminate primary tumors, but they cannot inhibit extensive tumor metastasis and local recurrence.

PEGylated Au DENPs ({(Au⁰)₂₅-G5·NH₂-mPEG₂₀}) are synthesized and used as a novel nonviral vector to deliver CpG to mature BMDCs for the subsequent activation of T cells for adoptive tumor immunotherapy.

We report novel superhydrophobic highly flexible composites based on a doubly cross-linked aerogel and carbon nanotubes for highly sensitive strain/pressure sensing.

Stimuli-responsive release of berberine 9-O-pyrazole alkyl derivative loaded in AS1411-functionalized graphene oxide nanosheets for chemo-photothermal synergetic therapy of cancer.

A nano-assembly of pH-sensitive doxorubicin prodrug and human serum albumin shows tumor pH-responsive aggregation, enhanced tumor retention and reduced cytotoxicity.

A multifunctional nanocomposite hydrogel for synergistic antibacterial wound therapy and healing promotion.

A novel RNA-triple-helix hydrogel for treatment of triple negative breast cancers (TNBCs) by incorporating RNA-triple-helix and siRNA duplexes of CXCR4 into the same RNA nanoparticles was developed, without the synthetic polycationic reagents.

A colorimetric and electrochemical dual-mode biosensor for thrombin based on the combination of a magnetic separation technique and a signal amplification strategy.

Compared with graphene quantum dots (GQDs), fluorine-containing GQDs (F-GQDs) present higher ¹O₂ generation under light irradiation and thus cause obvious toxicity to HepG2 cells. F-GQDs can be used as a photosensitizer for photodynamic therapy.

A lysosome-targeted near-infrared (NIR) fluorescent probe SHCy-C for detecting and imaging endogenous Cys in living cells has been developed.

Ferrocene-containing nanoparticles show reversible redox activity that could trigger drug release mediated by reactive oxygen species (ROS).

A silver crosslinked chitosan hydrogel controlled the release of bFGF to improve the regeneration of infectious skin wounds.

A PVA-based composite hydrogel with a biomimetic gradient structure as an artificial cartilage replacement was constructed by an extrusion 3D printing technique.

An injectable thermo-sensitive hydroxypropyl chitin hydrogel was applied for long-term sCT release, with enhanced osteogenic potential and hypocalcemic effects.