Fabrication, antibacterial activity and cytocompatibility of quaternary ammonium chitooligosaccharide functionalized polyurethane membrane via polydopamine adhesive layer.

In this study, to enhance the antibacterial activity and cytocompatibility of the electrospinning polyurethane (PU) fibrous membrane, quaternary ammonium chitooligosaccharide (G-COS) was immobilized on the fibrous membrane surface via an intermediate layer of polydopamine (PDOPA) to obtain the G-COS functionalized PU (G-C-D-PU), as a control, chitooligosaccharide (COS) functionalized PU fibrous membrane (C-D-PU) was prepared, too. Surface composition, morphology, hydrophilicity and surface energy of the original and modified PU fibrous membranes were characterized, which revealed that the surface roughness and hydrophilicity of the PU fibrous membrane were obviously increased by modified with COS and G-COS, respectively. Antibacterial experiment against E. coli and S. aureus indicated that antibacterial activity of the G-C-D-PU fibrous membrane was markedly superior to that of pure PU and C-D-PU fibrous membranes. In vitro cells culture experiments revealed that the adhesion and proliferation of NIH-3T3 cells on the PU fibrous membrane were improved by successively immobilized with PDOPA and COS as well as G-COS with the concentration of 2 g/L and 6 g/L. Moreover, the G-C-D-PU fibrous membranes with relative high G-COS content were more beneficial to the enhancement of antibacterial activity, but on the contrary, those with relative low G-COS content were more in favor of cell attachment and proliferation.

Antibacterial activity and cytocompatibility of chitooligosaccharide-modified polyurethane membrane via polydopamine adhesive layer.

The aim of this study was to provide a convenient surface modification method for polyurethane (PU) membrane and evaluate its influence on hydrophilicity, antibacterial activity and cell functions, which are the most important factors for wound dressings. For this purpose, chitooligosaccharide (COS) was modified onto the surface of PU membrane based on the self-polymerization of dopamine (DOPA). Surface composition, morphology, hydrophilicity and surface energy of the original and modified PU membranes were characterized. Surface roughness and hydrophilicity of the PU membrane were obviously increased by modified with polydopamine (PDOPA) and COS. Antibacterial experiment against Escherichia coli and Staphylococcus aureus indicated that antibacterial activity of PU membrane increased only slightly by modified with PDOPA, but increased significantly by further modified with COS. Cells culture results revealed that COS-functionalized PU membrane is more beneficial to the adhesion and proliferation of NIH-3T3 cells compared to the original and PDOPA-modified PU membranes.