Bioinspired Phosphorylcholine Coating for Surface Functionalization of Interventional Biomedical Implants with Bacterial Resistance and Anti-Encrustation Properties

Enhancing the lubrication property and bacterial resistance is extremely important for interventional biomedical implants to avoid soft tissue damage and biofilm formation. In this study, a zwitterionic phosphorylcholine coating (PMPC) was successfully developed to achieve surface functionalization of a polyurethane (PU)-based ureteral stent via subsurface "grafting from" photopolymerization. Typical surface characterizations such as Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and surface wettability and morphology analyses examined by scanning electron microscopy, atomic force microscopy, and transmission electron microscopy demonstrated that the phosphorylcholine polymer was grafted on the substrate with a thickness of 180 nm. Additionally, the tribological experiment performed by a universal material tester showed that the lubrication performance of PU-PMPC was significantly improved compared with that of PU. The in vitro experiments indicated that the PMPC coating was biocompatible and stably modified on the surface of the substrate with an excellent bacterial resistance rate of >90%. Furthermore, the result of the in vivo experiment showed that the anti-encrustation performance of the surface-functionalized ureteral stent was better than that of the bare ureteral stent. The great enhancement in the lubrication, bacterial resistance, and anti-encrustation properties of the phosphorylcholine coating was thought to be due to the hydration effects of the zwitterionic charges. In summary, the bioinspired zwitterionic phosphorylcholine coating developed herein achieved significantly improved lubrication, bacterial resistance, and anti-encrustation performances and could be used as a convenient approach for surface functionalization of interventional biomedical implants.