Plant mediated-green synthesis of zinc oxide nanoparticles: An insight into biomedical applications

Green synthesis of zinc oxide (ZnO) nanoparticles (NPs) using various plant extracts as reducing and capping agents has gained attention in recent research. The green synthesis of ZnO NPs offers several advantages such as being simple, eco-friendly, safe, cost-effective, and reproducible approach with high stability. Hence, this article provides an overview of zinc metal and ZnO compounds, and traditional chemical and physical synthesis of ZnO NPs with primary focuses on the green synthesis of ZnO NPs. This study discusses various plant extracts used and the proposed mechanisms in the green synthesis of ZnO NPs. Additionally, it explores the cytotoxic mechanisms of the green-synthesized ZnO NPs and addresses the various biomedical applications of ZnO NPs, including antibacterial, anticancer, antidiabetic, antioxidant, antifungal, antiviral, antiparasitic, anti-inflammatory, and wound healing. Moreover, the review critically discusses the toxicity of ZnO NPs and emphasizes the need for more toxicological studies to ensure the safety and facilitate the risk assessments and risk management of ZnO NPs. Furthermore, this review underlines the challenges associated with the translation process of ZnO NPs from bench to market, including the complex and time-consuming regulatory approval process for ZnO NPs, which requires a multidisciplinary approach involving scientists, regulators, and manufacturers.