Upconversion nanoparticles exhibit 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 examines various aspects, including the

Zinc oxide is a substance renowned for its remarkable ability to protect delicate skin. This calming ingredient has long been employed in a range of skincare products, from sunscreens to diaper rash creams, due to its outstanding protective characteristics. Forming a physical defense on the skin's top layer, zinc oxide effectively blocks harmful