Spray-coating of a hydrophobic poly(tetrafluoroethylene) membrane with a copolymer containing sulfobetaine methacrylamide to boost hydration and reduce biofouling in view of improving diabetic wound management and alleviate the immune response

Abstract

In spite of being an application that tends to be overlooked by membranologists, chronic skin wound healing can be tackled by innovating approaches starring advanced porous membrane materials creating a suitable environment for wound management. Here, we fabricated porous poly(tetrafluoroethylene) membranes decorated with sulfobetaine methacrylamide moieties using a spray-coating method following surface activation by plasma. The zwitterionization permitted to reach improved hydration (WCA of 70°, down from 114°) and quasi-neutral zeta potential (−3 mV up from −68 mV) which rationalized low non-specific protein adsorption (reduced by 88% with fibrinogen), low bacterial and blood fouling (Escherichia coli and whole blood attachment decreased by 98% and 92%, respectively), all the while maintaining very high survival rate of fibroblasts (89%). Improved hydrophilicity and porous features arose in a water vapor transmission rate (>3000 g m⁻².day⁻¹) thought to be appropriate to the healing of highly exuding chronic wounds. Applied on skin wounds of diabetic rats, the zwitterionic antifouling biocompatible porous membranes led to faster closure than a commercial dressing (87% vs. 79% after 14 days) by efficiently alleviating the inflammation response. From a histological analysis ran during the inflammation period, infiltrates in the tissue were measured to be 830 ± 240 cells/mm², against 1507 ± 321 cells/mm² with the commercial material. Thus, the results of this work demonstrate the benefit of using antifouling porous membranes which reduce the immune response, leading to better and faster healing of chronic wounds. This widens the range of applications for such membranes.