Upconversion nanoparticles demonstrate unique optical properties, making them attractive for applications in bioimaging, sensing, and therapy. However, their potential toxicity remains a substantial concern. This review aims to provide a thorough analysis of the toxicity linked with upconversion nanoparticles. It explores various aspects, including

Zinc oxide is a mineral renowned for its remarkable strength to safeguard delicate skin. This calming component has long been employed in a range of skincare products, from sunscreens to diaper rash creams, due to its outstanding protective characteristics. Establishing a physical barrier on the skin's surface, zinc oxide effectively blocks harmf