Scientists linked to the Research Center for Redox Processes in Biomedicine (Redoxoma) at the University of São Paulo (USP) have developed a method to obtain coated silica particles with potential use in the manufacture of more natural, ecological, safe and broader sunscreens. .
The process created at Redoxoma – a FAPESP Research, Innovation and Diffusion Center (CEPID) – had the “Invention Patent” recently granted by the National Institute of Industrial Property (INPI), within the scope of the project “Process for obtaining coated nanosilica and its use.”
“The photoprotectors currently used act very well against the effects of ultraviolet B radiation. [UVB], which penetrates the most superficial layers of the skin. In other words, they are effective in preventing redness and other acute inflammatory reactions that occur during sun exposure and in the hours afterwards”, explains Mauricio da Silva Baptista, professor in the Department of Biochemistry at IQ-USP and coordinator of the work, carried out during his master's degree. André José Cardoso de Miranda, defended in 2016.
“However, they only partially protect against UVA rays, which cause photoaging, cancer, cataracts and age-related macular degeneration. Furthermore, they completely allow visible light to pass through, the spectral range that forms the highest levels of free radicals upon exposure to the sun. This is a problem, as it is proven that all skin cells respond to this radiation and that its excess causes reasonably severe damage, with chronic consequences, such as cellular aging”, adds Baptista.
In the new process, silica particles are synthesized and coated with an ultra-thin film of melanin, capable of preventing these rays from reaching and being absorbed by the DNA present in the nucleus of skin cells. “This is the great commercial advantage expected for the invention”, says Baptista.
As it involves only natural products (silica particles are basically a derivative of sand and melanin is a natural polymer originating from the amino acid tyrosine), the process also gives rise to a more ecological protector. “Many commercial sunscreens are being banned because some of their molecules, such as titanium dioxide, cause significant damage to the environment, such as the death of corals”, recalls Baptista.
Another advantage is that there is no risk of systemic damage, as the particle does not penetrate the skin like some commercial photoprotectors – which have already been associated with effects equivalent to the ingestion of hormones.
Low cost
The patented method has yet another advantage: if developed and scaled by the cosmetic industry, it can be affordable. This is because the tyrosinase enzyme, used in the synthesis of melanin, is not directly linked to the silica particle – which increases its catalytic activity (to accelerate the transformation of tyrosine and melanin) and allows the reuse of this input.
“Our expectation is that, with the patent granted, we will be able to approach companies to develop the sunscreen on a commercial level, especially since there is nothing even remotely similar to our process on the market”, says Baptista.
According to the researcher, the closest thing to the technology are colored BB Creams, which are made with iron oxides and have a sun protection factor (SPF) and also protect against visible light. However, according to the researcher, these products can also have unfavorable consequences for the body and the environment.
Patent obtained by the Redoxoma group has a validity period of 20 years, starting in October 2016. It is available in the international and INPI patent databases.
By Julia Moióli | FAPESP Agency