Chitosan Schiff-Base Hydrogel Sunscreen: A Multifunctional Hybrid Network with Antioxidant, Ultraviolet-Shielding, and Self-Healing Properties.

Prolonged exposure to ultraviolet (UV) radiation can cause erythema, sunburn, inflammation, and even skin cancer. Sunscreen is highly effective in protecting against UV radiation. Hydrogels, due to their similarity to the skin's extracellular matrix, flexibility, and high water content, have been widely used for sunscreen applications.

Dual antioxidant-photosensitizing hydrogel system: Cross-linking of chitosan with tannic acid for enhanced photodynamic efficacy.

Herein, a new antioxidant-photosensitizing hydrogel based on chitosan has been developed to control photodynamic therapy (PDT) activity in cancer treatment. In PDT, photosensitizers generate reactive oxygen species (ROS) during photochemical reactions, leading oxidative damage to cancer cells. However, high ROS levels are lethal to non-target healthy cells and tissues such as endothelial cells and blood cells.