Antibacterial PCL electrospun membranes containing synthetic polypeptides for biomedical purposes

Electrospun membranes endowed with efficient bactericidal properties have been widely applied in the biomedical field. In this work, polyhedral oligomeric silsesquioxane (POSS) and i-butyl-capped polypeptides, POSS-poly(lysine-co-valine) (PKV) and i-butyl-poly(lysine-co-valine) (KV), were prepared via ring-opening polymerization of N-carboxyanhydride lysine and valine monomers. The synthetic polypeptides, PKV and KV, were facilely added in the poly(ε-caprolactone) (PCL) solution for electrospinning to enable the electrospun membranes to have antibacterial properties for biomedical applications. The PCL/polypeptide electrospun membranes detected by attenuated total reflectance Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy indicated the existence of polypeptides on the fiber surface, which favored the antibacterial performance. The wettability results revealed the enhanced hydrophilicity of the electrospun membranes by introducing the polypeptides. The antibacterial activities of the electrospun membranes were evident against Escherichia coli and Staphylococcus aureus with bacterial membrane disruption mechanism demonstrated by Live/Dead assay. The relative cell viability for vascular smooth muscle cells was higher than 80%, and the hemolysis of the electrospun membranes was lower than 5%. The PCL/polypeptide electrospun membranes with biocompatibility and antibacterial activity could have potential for applications in vascular grafts or wound healing.