A New Approach to UV Protection by Direct Surface Functionalization of TiO2 with the Antioxidant Polyphenol Dihydroxyphenyl Benzimidazole Carboxylic Acid

Abstract

Skin cancer is the most common malignant cancer with an incidence of 1 million cases/year. It is well known that exposure to UV radiation from sunlight leads the most frequent risk factors for several skin disorders including skin cancer. Sunscreen filters represent a valid protection against dangerous effects derived from UV radiation, and they can be divided in organic and inorganic UV filters. Adding, at the product formulation, molecules with booster effect, or also substances that can increase the protecting effectiveness via synergic mechanisms, can further enhance their protection activity. Moreover, this approach leads to develop formulations with high SPF (Sun Protection Factor) with a reduced content of UV filters, this is in line with the recent decisions of yet a few countries (Palau, Thailand, Philippines, and Hawaii) to ban some sunscreen filters to preserve marine environments (i.e., reef). In this work, a new class of sunscreen UV filters has been synthesized, by means the combination of physical filter and Oxisol, an antioxidant molecule with booster effect. In this study, the synthesis of new physical multifunctional ingredients is reported, by means the direct surface functionalization of inorganic filters (in particular TiO2) with Oxisol. In this study, the full characterization of these multifunctional ingredients is also reported, in addition to the cytotoxicity tests, the photocatalytic activity and the rheological properties involved on skin application.

Application of Marine Microbial Natural Products in Cosmetics

“…Part of the UV radiation emitted by the sun is absorbed by oxygen molecules in the stratosphere (UVC, 100–290 nm), part is absorbed by the ozone layer (UVB, 290–320 nm), and the remainder of UVA radiation (UVA, 320–400 nm) and a small part of UVB are transmitted to the ground ( Battistin et al, 2020 ). Basking in the sun can help the conversion of 7-dehydrocholesterol into vitamin D in human skin, but long-term exposure to UV light causes mutagenic and non-specific damage to the epidermis.…”

Titanium Dioxide Nanoparticles in Food and Personal Care Products—What Do We Know about Their Safety?

“…The authors suggested the inclusion of these materials into sunscreen products [ 121 ]. In another study, coating of TiO 2 NPs with dihydroxyphenyl benzimidazole carboxylic acid (Oxisol) not only led to photolytic activity reduction, but also boosted its antioxidant effects and stabilization of the formulation [ 122 ]. By modifying the surface of TiO 2 NPs, it is also possible to improve the appearance of a sunscreen formulation, as formulations containing TiO 2 NPs modified with a complexing compound, p -toluene sulfonic acid, were found to be more transparent [ 123 ].…”

Nano-Structured Lignin as Green Antioxidant and UV Shielding Ingredient for Sunscreen Applications

“…In a typical high sun protection factor (SPF) sunscreen, the final concentration of PMFs and OCFs can reach 45% by weight [ 7 ]. In addition, UV boosters are used to further increase the SPF by physical effect, tuning the ratio between the UV shielding efficiency and the total UV filter concentration [ 8 ]. UV boosters are usually composed of plastic micro-sized spheres from petroleum origin, such as styrene/acrylate copolymers, that are well recognized as a waste in water pollution [ 9 ].…”