Modification of polyurethaneurea with PEG and YIGSR peptide to enhance endothelialization without platelet adhesion

Improved endothelialization without platelet adhesion is essential to enhance the long‐term patency of synthetic vascular grafts and other blood‐contacting devices. We have developed a dually modified polyurethaneurea by incorporating endothelial cell adhesive YIGSR peptide sequences as chain extenders and nonthrombogenic PEG as a soft segment (PUUYIGSR‐PEG) in the polymer backbone. PUUYIGSR‐PEG was successfully synthesized and characterized by proton NMR, FTIR, GPC, DSC, ESCA, and contact angle measurement. Despite having similar molecular weight, the peptide/PEG‐modified polyurethaneurea (PUUYIGSR‐PEG) showed superior mechanical properties compared to the control PEG‐modified polyurethaneurea (PUUPPD‐PEG). Virtually no platelet adhesion was observed on PUUYIGSR‐PEG, while endothelial cell adhesion, spreading, and migration were significantly greater on PUUYIGSR‐PEG compared to PUUPPD‐PEG. Thus, this bioactive polymer may be an appropriate biomaterial for small diameter vascular grafts. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 72B: 131–139, 2005