Green Synthesis of Zno and Cuo Nanostructures Using Plant Extracts: A Sustainable Route from Natural Resources to Biomedical Innovation

Abstract

Zinc oxide (ZnO) and copper oxide (CuO) nanostructures are among the most widely investigated metal oxide nanomaterials in biomedicine, owing to their broad-spectrum antimicrobial, anticancer, and wound-healing activity combined with comparatively low cost and favorable biocompatibility. While these nanomaterials are conventionally produced by physical and chemical routes such as magnetron sputtering, ion-plasma deposition, and chemical precipitation, a rapidly growing body of literature has established plant-extract-mediated green synthesis as a sustainable, low-toxicity alternative that directly converts natural botanical resources into functional biomedical nanomaterials. This review synthesizes recent evidence on the mechanisms of plant-mediated green synthesis of ZnO and CuO nanostructures, their demonstrated antimicrobial, anticancer, antioxidant, and wound-healing efficacy, and the methodological relationship between green and physical synthesis routes for these same oxide systems. The reviewed literature demonstrates that green-synthesized ZnO-CuO bimetallic and trimetallic nanostructures achieve potent, dose-dependent anticancer cytotoxicity against breast cancer cell lines, near-complete biofilm reduction against multidrug-resistant bacterial pathogens, and accelerated diabetic wound closure exceeding 90 percent within one week in preclinical models, positioning plant-mediated synthesis as a scientifically and environmentally compelling complement to physically deposited ZnO/CuO thin-film systems. Given the convergence of sustainability imperatives, antimicrobial resistance concerns, and the demonstrated multifunctionality of these nanostructures, this area represents one of the most active and rapidly citing fronts in contemporary nanomedicine research.