Polymer/TiO2 Hybrid Vesicles for Excellent UV Screening and Effective Encapsulation of Antioxidant Agents

Presented in this paper is a hybrid polymer/titanium dioxide (TiO2) vesicle that has excellent UV-screening efficacy and strong capacity to encapsulate antioxidant agents. Poly(ethylene oxide)-block-poly(2-(dimethylamino)ethyl methacrylate)-block-polystyrene (PEO-b-PDMAEMA-b-PS) triblock terpolymer was synthesized by atom transfer radical polymerization (ATRP) and then self-assembled into vesicles. Those vesicles showed excellent UV-screening property due to the scattering by vesicles and the absorption by PS vesicle membrane. The selective deposition of solvophobic tetrabutyl titanate in the PDMAEMA shell and the PS membrane of the vesicles led to the formation of polymer/TiO2 hybrid vesicles, resulting in an enhanced UV-screening property by further reflecting and scattering UV radiation. The vesicles can effectively encapsulate antioxidant agents such as ferulic acid (up to 57%), showing a rapid antioxidant capability (within 1 min) and a long-lasting antioxidant effect.