Zinc Oxide Nanoparticles as Versatile Nanoplatforms: Design Principles, Functional Properties, and Application Pathways

Zinc oxide nanoparticles (ZnO NPs) have attracted significant attention due to their distinctive physicochemical characteristics and growing relevance across biomedical, environmental, and industrial domains, prompting sustained research into their design and functional performance. This review systematically examines reported synthesis approaches for ZnO nanoparticles, alongside commonly employed characterization techniques used to evaluate their structural, optical, and surface properties, with emphasis on how these parameters influence biological interactions. The article consolidates findings from recent studies describing the antimicrobial, anticancer, and drug-delivery-related functionalities of ZnO nanoparticles, highlighting proposed mechanisms such as reactive oxygen species generation, surface-mediated interactions, and controlled payload release. Additionally, the review summarizes existing evidence regarding biocompatibility, toxicity concerns, and stability issues that currently limit translational implementation. Collectively, the analyzed literature indicates that controlled synthesis and surface engineering play a critical role in tailoring ZnO nanoparticle performance for specific biomedical applications. In conclusion, this review identifies key challenges and emerging opportunities associated with ZnO nanoparticles and underscores the need for standardized evaluation frameworks and mechanistic clarity to support their responsible integration into future healthcare technologies.