Zwitterionic polymer coating on medical sponges via a silane coupling agent for inhibiting bacterial and fibroblast adhesion

Medical sponges are widely used in wound management, however the adhesion of bacterial or wound tissue to them may cause infection or secondary damage to patients. In this work, anti-bioadhesive polyvinyl alcohol-formaldehyde sponges with zwitterionic coating were prepared by the dip-coating process using the reactive zwitterionic phosphorylcholineated polyvinylamine (PVAm-PC) and commercial silane coupling agent KH560 at different mass ratios, and their structure, physicochemical, biocompatible and anti-bioadhesive properties were investigated. As compared to pristine sponges, the PVAm-PC-KH560 (PPK) modified sponges with the interconnected pore structure had almost unchanged water vapor transmission rate but decreased swelling degree to a certain extent possibly due to the formation of rigid Si– O –Si networks in the sponges. In vitro biological evaluation confirmed that PVAm-PC-KH560 modified sponges were not cytotoxic and had good resistance to bacteria adhesion with only ∼16% and ∼11% relative bacterial adhesion rate for E. coli and S. aureus respectively. And the optimized PPK-2 sponge showed the best comprehensive bacterial adhesion inhibition properties. Further adhesion assay of L929 fibroblasts showed that PPK-2 sponge could significantly reduce the adhesion of L929 fibroblasts. The results strongly suggested that dip-coating with zwitterionic PVAm-PC and KH560 may provide a promising and facile method to construct an anti-bioadhesive surface for biomedical applications.