Sulfonated poly(ethylene oxide)-grafted polyurethane copolymer for biomedical applications

Sulfonated poly(ethylene oxide) (PEO-SO3)-grafted polyurethane (PU) copolymer (PU-PEO-SO3) was developed for utilization as a material for biomedical applications. Its bulk properties and biocompatibility were investigated and the results were compared to those of PU and PU-PEO (not sulfonated). PU-PEO-SO3 copolymer showed higher water uptake than PU and PU-PEO, indicative of increased hydrophilicity due to the grafting of PEO-SO3. Compared with PU, PU-PEO-SO3 displayed lower glass transition temperature (Tg) and melting endotherm from DSC analysis, suggesting the increase of microphase separation and the suppression of hard-segment packing. PU-PEO-SO3 had practically similar mechanical properties to PU, indicating that the chemical modification of PU was accomplished without reducing its bulk properties. From the results of biocompatibility tests, PU-PEO-SO3 copolymer showed significantly lower adhesion of platelets and S. epidermidis than PU control and PU-PEO. In addition, the platelet factor 4 (PF4) released from platelets was the lowest in PU-PEO-SO3 among the test materials. PU-PEO-SO3 copolymer, which has excellent mechanical properties and biocompatibility, is expected to be useful as coating, molding, and blending materials for artificial organs and medical devices.