Biogenic chitosan anchored Cu2O/ZnO nanocomposite: unlocking synergy for drug delivery, antineoplastic action, and wound repair

Abstract

The clinical efficacy of many chemotherapeutic agents is often limited by inefficient drug delivery, poor selectivity toward cancer cells, and insufficient support for tissue regeneration. To address these challenges, we report the green synthesis of a multifunctional chitosan-anchored Cu₂O/ZnO nanocomposite (CS-Cu₂O/ZnO NC) using water calyx fluid (WCF) extracted from Spathodea campanulata flower buds as a natural reducing and stabilizing agent. Structural and physicochemical characterization using X-ray diffraction confirmed the crystalline phases of Cu₂O and ZnO, while UV-Vis spectroscopy showed characteristic absorption in the 270–320 nm region indicating nanoparticle formation. FTIR analysis verified the successful integration of chitosan and phytochemical functional groups with metal oxides. Transmission electron microscopy revealed quasi-spherical nanoparticles uniformly distributed within the polymer matrix with an average particle size of 20–40 nm, whereas dynamic light scattering showed a hydrodynamic diameter of ∼89.3 nm with a zeta potential of −29.4 mV, confirming good colloidal stability. The nanocomposite was employed as a carrier for cisplatin and exhibited high drug loading efficiency with a biphasic release profile, achieving 94.88% cumulative drug release over 72 h. In vitro cytotoxicity studies demonstrated enhanced anticancer activity against A375 skin cancer cells (IC₅₀ = 29.84 µg mL⁻¹) with comparatively lower toxicity toward L929 fibroblast cells. Furthermore, scratch wound healing assays revealed significant fibroblast cell migration and accelerated wound closure within 24 h, highlighting the regenerative potential of the nanocomposite. Overall, the developed green-synthesized CS-Cu₂O/ZnO nanocomposite represents a sustainable multifunctional platform for controlled drug delivery, cancer therapy, and wound healing applications.