Study On The Peptide Modified Poly(Trimethylene Carbonate) And Its Properties

Coronary artery disease has become one of the major diseases of threating to human’s life today. Drug-eluting stents(DES) for the treatment of coronary atherosclerosis has opened a new milestone, it can significantly reduce restenosis incidence after implanting DES. But late thrombosis still occurres caused by the polymer coating and the drug in the DES. Therefore, the new kind of polymer chosen for DES carrier is very important. Poly(trimethylene carbonate)(PTMC) exhibits its potential as a drug-loaded coating owing to some biocompatibility, high mechanical properties and surface corrosion degradation characteristics. However, the earlier research demostrated that PTMC could inhibit adhesion and proliferation of vascular endothelial cell(EC).In this study, the peptides of RGD (Arg-Gly-Asp) and REDV (Arg-Glu-Asp-Val) were chosen to modify the surface of PTMC in order to promote adhesion and proliferation of EC The PTMC films modified by RGD or REDV were prepared respectively through polydopamine deposition on PTMC menbrance and the reaction between peptides and polydopamine subsequently. Then, the component and properties of fims were determined by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy(SEM), acid organge II analysis, water contact angle mesasurement and quartz crystal microbalance with Dissipation Monitoring (QCM-D), Cytocompatibility and hemocompatibility of the modified films were evaluated in vitro. The result as follows:The films modified by RGD or REDV were fabricated successfully. The hydrophilicity of PTMC film modified by polydopamine was better than that of pure PTMC, and the water contact angle increased with the increase of the deposition time, but there was no significant difference between the RGD-modified PTMC and REDV-modified PTMC. Compared with unmodified PTMC film, the average roughness of the modified PTMC was increased. The amount of polydopamine on PTMC film increased with deposition time increasing, when up to72h, the amine content of polydopamine on the film was5.98X10-9nmol/cm2. The density of the peptide fixed on the modified-PTMC film also increased with the increase of the content of polydopamine. The results of human mbilical vein endothelial cells(EC) and smooth muscle cell(SMC) in vitro evaluation indicated that the RGD PTMC could promote the adhesion, spreading and proliferation of EC and SMC, however, the REDV modified PTMC only could promote the adhesion, spreading and proliferation of EC but prohibit adhesion and proliferation of SMC. This result also suggested that the REDV-immobilzied PTMC had the the function of EC selective attachment.The results of in vitro hemocompatibility evaluation indicated that the RGD-modified and REDV-modified PTMC in some extent could inhibit platelet adhesion and activation, but they did not show significant impact on endogenous and exogenous pathway of blood coagulation. Meanwhile, the unmodified PTMC exhibited better performance in suppressing fibrinogen denaturation than the RGD-modified and REDV-modified PTMC.