Deposition of thin films of pheomelanin and eumelanin in silic nanoparticles for development of sunscreen with visible protection

• Grant number: 19/11234-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2019
• End date: January 17, 2021
• Field of knowledge: Biological Sciences - Biophysics - Radiology and Photobiology
• Principal Investigator: Mauricio da Silva Baptista
• Grantee: Mariana Nishino
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 13/07937-8 - Redoxome - Redox Processes in Biomedicine, AP.CEPID

Abstract

The health of the skin and hair in relation to the sun depends on numerous factors, several revealed as yet unknown. Sunscreens protect against ultraviolet radiation, but allow photons in the visible zone to penetrate freely into the skin. Recent scientific work from our and other research groups has proved that electromagnetic radiation in the visible zone affects the skin in a similar way to the radiation in the UVA band. Fotossensibilizadores naturais (flavinas, melaninas, liposfucina), quando excitados pela luz visível, geram 1O2 e outras espécies reativas de oxigênio, provocando danos ao DNA e à outras biomoléculas celulares. In this sense, an invention patented by our research group (BR 10 2016 024262 2) consists of synthesizing silica nanoparticles (NPs) overlay with thin films of melanin in purpose to produce a material that absorbs light throughout the ultraviolet zone and visible and can be applied to sunscreens. However, to make this application more application on an industrial scale, it is necessary to optimize the process described in the patent, in order to minimize costs and time for the preparation of the material, which is one of the objectives of the actual project. Beyond this optimization, proposed to obtain NPs with different colorations for adjust to the skin tones of each individual, varying the proportion and quantity of each of the two types of melanin (eumelanin and pheomelanin) deposited on the silica. The proportion of each melanin in the overlay will be controlled by the quantity of tyrosine and cysteine added to the reaction.