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 comprehensive analysis of the toxicity associated with upconversion nanoparticles. It examines various aspects,

Zinc oxide is a mineral renowned for its remarkable strength to safeguard delicate skin. This soothing element has long been used 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 exterior, zinc oxide effectively reflects harmful