Upconversion nanoparticles possess 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 investigates various aspects, including

Zinc oxide is a mineral renowned for its remarkable ability to safeguard delicate skin. This soothing component has long been utilized in a variety of skincare products, from sunscreens to diaper rash creams, due to its exceptional protective characteristics. Forming a physical defense on the skin's exterior, zinc oxide effectively reflects harmf