Zinc Oxide Nanoparticles in Biomedical Applications: Advances in Synthesis, Antimicrobial Properties, and Toxicity Considerations

Zinc oxide (ZnO) nanoparticles are promising nanotherapeutics used in several biomedical applications. Some of the unique features of ZnO nanoparticles are good optical, piezoelectric, and semiconducting properties together with good biodegradability and low toxicity. The zinc ion is also an important trace element crucial for adults for metabolism. ZnO nanoparticles are known to exhibit excellent anticancer, antibacterial, antiviral, and antifungal activities. The aforementioned biological activities are attributed to their capability to induce apoptosis and generate reactive oxygen species. ZnO nanoparticles have also been explored as drug nanocarriers and bioactive agents for targeted drug delivery with reduced side effects and synergistic effects. Some available data have shown the risk associated with the uncontrollable use of nanoformulations of zinc. The increasing use of ZnO nanoparticles offers great benefits biomedically, but its toxic effects over a prolonged period need to be studied. The design of ZnO nanoparticles for biomedical applications has a promising capability to flourish with the potential of clinical translation. This chapter reports a summary of the recent advances in the synthesis of ZnO nanoparticles and platforms loaded with ZnO nanoparticles with antimicrobial activities—antibacterial, antifungal, antiviral, and antiparasitic, and toxicity effects.