A novel strategy to graft RGD peptide on biomaterials surfaces for endothelization of small-diamater vascular grafts and tissue engineering blood vessel

To improve the performance of small-diamater vascular grafts, endothelization of biomaterials surfaces and tissue engineering are more promising strategies to fabricate small-diamater vascular grafts. In this study, a Gly-Arg-Gly-Asp-Ser-Pro (GRGDSP) peptide was grafted on the surfaces of poly(carbonate urethane)s (PCUs), with photoactive 4-benzoylbenzoic acid (BBA) by UV irradiation. The photoactive peptides (BBM-GRGDSP) were synthesized with classical active ester of peptide synthesis. The modified surfaces of PCU with the photoactive RGD peptides were characterized by water contact angle measurement and X-ray Photoelectron Spectroscopy (XPS), which results suggested that the peptides were successfully grafted on the PCU surfaces. The effect of these modified surfaces on endothelial cells (ECs) adhesion and proliferation was examined over 72 h. PCU surfaces coupled with the synthetic photoactive RGD peptides, as characterized with phase contrast microscope and the metabolic activity (MTT) assay enhanced ECs proliferation and spreading with increasing concentration of RGD peptides grafted on their surfaces. Increased retention of ECs was also observed on the polymers surfaces under flow shear stress conditions. The results demonstrated that GRGDSP peptides grafted on the surfaces of polymers with photoactive 4-benzoylbenzoic acids could be an efficient method of fabrication for artificial small-diamater blood vessels. The modified polymer is expected to be used for small-diamater vascular grafts and functional tissue engineered blood vessels to improve ECs adhesion and retention on the polymer surfaces under flow shear stress conditions.