Centella asiatica extract-SiO 2 nanocomposite: More than a drug-delivery system for skin protection from oxidative damage.

An innovative nanotechnology-based approach was used for the preparation of Centella asiatica (C. asiatica) extract-SiO 2 nanocomposites, specifically tailored for skin protection from oxidative damage. Different amounts of C. asiatica glycolic extract (1.0, 3.0, 5.0, and 10.0 wt %) and fumed silica were used to prepare the nanocomposites by means of ball milling method. The influence of both composition of the starting mixture and milling time on the final products was evaluated by different techniques such as X-ray powder diffraction, scanning electron microscopy, infrared spectroscopy, thermogravimetric analysis, and nitrogen sorption analysis. Results confirmed the integrity of the natural extract after the milling process, and its successful loading in the silica matrix. No cytotoxicity was observed for the obtained nanocomposites, which showed high in-vitro ability to scavenge 2,2-diphenyl-1-picrylhydrazyl and to protect human keratinocytes from damages induced with hydrogen peroxide.