Control of optical properties of human skin by embedding light scattering nanoparticles

Nowadays there is an acute problem to protect human skin against harmful influence of violet and ultraviolet solar radiation. The aim of this research is to evaluate, how optical properties of the horny layer of human skin can be changed by imbedding the titanium dioxide (TiO2) fine particles in order to achieve the maximal attenuation of the UV solar radiation. In-depth distribution in the skin of TiO2 particles typically achieved with the sunscreens is determined experimentally by the tape-stripping technique. Computer code implementing the Monte Carlo method is used to simulate photon migration within 20-μm thick horny layer partially filled with nano-sized TiO2 spheres. Dependencies of absorbed by and reflected from, as well as transmitted through the horny layer UV radiation of two wavelengths (290.5 and 400 nm) on the concentration of TiO2 particles are obtained and analyzed.