Bioengineered zinc oxide nanoparticles: Chemical, green, biological fabrication methods and its potential biomedical applications

Abstract The multifunctional characteristics of zinc oxide nanoparticles (ZnO NPs) demonstrate a wide variety and attractiveness of therapeutic and diagnostic properties. Biocompatible ZnO NPs promise to improve biomedical properties due to their excellent physical and chemical properties, tiny size (1–100 nm), low toxicity and are generally considered to be safe. This review focuses on specific critical aspects of various fabrication methods (chemical, green, and biological) that aid in the development of acceptable multifunctional ZnO NPs in the field of nanomedicine. Outlining the conjugation of ZnO NPs highlights the enhancement of biomedical capacity while lowering toxicity. When these ZnO NPs are exposed to biological micro-environments, biocompatibility, biodistribution, and toxicity have been discussed concerning their size, geometry, and surface chemistry. The final section focuses on recent biomedical applications of ZnO NPs, specifically therapeutic delivery, anticancer, antimicrobial, bioimaging, antidiabetic, anti-inflammatory, and wound healing as well as agricultural potential. Importantly, the chronic use of the smaller-sized ZnO NPs causes dose-dependent toxicity. Overall, this review provides the recent developments and future perspectives of ZnO NPs.