Fabrication of pH-responsive hydrophobic/hydrophilic antibacterial polyhydroxybutyrate/poly-ε-caprolactone fibrous membranes for biomedical application

Abstract

The clinical microbial infection has been a common syndrome and a serious threat to patients, and the biodegradable biomaterials with antibacterial property attracted increasing attention to replace traditional biomaterials including packaging and bandages. In this study, we generated fibrous membranes with biodegradable polyester polyhydroxybutyrate and poly-ε-caprolactone (PHB/PCL) by electrospinning, and synthesized containing N-halamine quaternary ammonium salt (HQAS) as antibacterial agent. Dimethylaminoethyl methacrylate (DMAEMA) as pH-responsive hydrophobic agent was grafted onto PHB/PCL fibrous membranes by in situ polymerization. The hydrophilic and the hydrophobic membranes were obtained with HCl and NH4OH treatments, respectively. On one hand, the membrane manifested prominent antimicrobial efficacy against E. coli O157:H7 (ATCC 43895) and S. aureus (ATCC 6538) when the surface was hydrophilic after further treatment by HCl solution, and the membrane had prominent thrombogenicity with 60.6% of BCI. On the other hand, after further treatment by NH4OH solution, the membrane showed poor antibacterial efficacy against E. coli O157:H7, while the membrane surface exhibited excellent hydrophobicity with an average contact angle of 134oand self-cleaning properties to reduce bacterial adhesion. In addition, the pH-responsive hydrophilic/hydrophobic membranes showed good stability and durability towards UVA light exposure and storage. Therefore, these pH-responsive hydrophilic/hydrophobic antibacterial membranes may have great potential for application in biomedical materials.