Mesoporous Titania Nanoparticles for a High-End Valorization of Vitis vinifera Grape Marc Extracts

Mesoporous titania nanoparticles (NPs) can be used for encapsulation polyphenols, with applications in the food industry, cosmetics, or biomedicine. TiO2 NPs were synthesized using the sol-gel method combined with solvothermal treatment. TiO2 NPs were characterized through X-ray diffraction, FTIR spectroscopy, the N2 adsorption method, scanning and transmission electron microscopy, and thermal analysis. The sample prepared using Pluronic F127 presented a higher surface area and less agglomerated NPs than the samples synthesized with Pluronic P123. Grape marc (GM), a by-product from wine production, can be exploited for preparing extracts with good antioxidant properties. In this regard, we prepared hydroethanolic and ethanolic GM extracts from two cultivars, Feteasca Neagra (FN) and Pinot Noir. The extract components were determined by spectrometric analyses and HPLC. The extract with the highest radical scavenging activity, the hydroethanolic FN extract, was encapsulated in titania (FN@TiO2) and compared with SBA-15 silica support. Both resulting materials showed biocompatibility on the NCTC fibroblast cell line in a 50–300 µg/mL concentration range after 48 h of incubation and even better radical scavenging potential than the free extract. Although titania has a lower capacity to host polyphenols than SBA-15, the FN@TiO2 sample shows better cytocompatibility (up to 700 µmg/mL), and therefore, it could be used for skin-care products.