Bionic shark skin replica and zwitterionic polymer brushes functionalized PDMS membrane for anti-fouling and wound dressing applications

In this study, the double-faced bionic functionalized polydimethylsiloxane (PDMS) membranes were successfully fabricated for the wound dressing applications. Bionic (shark skin) structure was replicated on the outer layer of PDMS membranes to form the super-hydrophobic surface for inhibiting the bacteria adhesion. Furthermore, the zwitterionic polymer (2-methacryloyloxyethyl phosphorylcholine, MPC) brushes were immobilized on the internal layer of polyvinyl alcohol (PVA) modified PDMS membranes by the atmospheric plasma-induce polymerization for enhancing wound repairs and absorbing the wound exudates. The characteristics of the bionic functionalized PDMS membranes were evaluated by scanning electron microscopy (SEM), energy dispersive Xray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), contact angle (CA) measurement, and Xray photoelectron spectroscopy (XPS). The results indicate that the bionic outer layer of PDMS membrane exhibited super-hydrophobic surface (CA: > 120 degrees) by shark skin replica, whereas the internal layer displayed super-hydrophilic surface (CA:< 10 degrees), due to the immobilization of PMPC polymer brushes on the PVA-modified PDMS membrane. Therefore, the bionic outer layer of PDMS membranes could not only avoid the external bacteria adhesion to protect the wound, but also PMPC and PVA modified internal layer can improve the hydrophilicity and biocompatibility to hasten the wound repairs.