Nanofibrous sunscreen

Abstract

The widely known and understood harmfulness of ultraviolet rays (UV) continues to prompt improved skin protection and shielding from UV rays. However, current liquid or stick sunscreen can lead to various skin problems due to its poor water resistance, toxicity, and the residue left on the skin after removal. Moreover, the durability of most sunscreen is short term such that inconvenient regular application is required. This study reports a new type of sunscreen; medical grade polyurethane is enhanced with TiO₂ and can be applied quickly and uniformly to the skin via a novel portable electrospinning system which is modularized and designed for easy replacement for the convenience of users. The nanofibers solidify and are chemically stable, resulting in a nanofibrous sunscreen that does not dissolve in sweat or water but efficiently blocks microscopic dust while allowing air and vapor to pass through. Due to its flexibility and stretchability, it is highly conformable and can be stretched and relaxed repeatably on the skin without falling off. Unlike liquid sunscreen, the nanofibrous sunscreen can be readily removed from the skin without leaving residue. The developed nanofibrous sunscreen can be used in daily life and in medical applications, e.g., for patients with organ transplants or skin disease who are especially vulnerable to UV rays.