Enhanced blood compatibility of polyurethane functionalized with sulfobetaine.

The purpose of this work is to develop a biocompatible polyurethane surface by the tailoring of sulfobetaine. The polyurethane film was first grafted polymerization with acrylic acid by ozonization, followed by immobilizing sulfobetaine via two routes: (i) synthesize primary amine group terminated sulfobetaine and then couple onto the surface of polyurethane using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC); (ii) couple the primary amine group terminated tertiary amine onto the surface of polyurethane primarily using EDC and then form sulfobetaine through a ring-opening reaction between tertiary amine and 1,3-propanesultone (PS). The reaction process was monitored with attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). The blood compatibility was evaluated by a hemolytic test and platelet-rich plasma (PRP) adhesion experiment. Little hemolysis took place on the surface of polyurethane grafted with sulfobetaine. Platelets adhering on the surface of grafted polyurethane decreased greatly as compared to the original after 1 and 3h of incubation with PRP.