| When polymer materials come in contact with organisms, significant responses such as thrombus and thrombogenicity occur. Therefore, the suface modification of polymeric materials is required clinically to avoid clot formation. As available surface modification technologies, Plasma grafting polymerization and surface coating have been abroadly used in biomaterials modification field.In this article, 2-methacryloyloxyethyl phosphorylcholine (MPC) was firstly synthesized by a"two-step"method. Then a copolymer of MPC and n-butyl methacrylate(BMA) was prepared by free radical polymerization. ATR-FTIR, XPS and ~1H-NMR were introduced to confirm its chemical structure. Secondly, grafting of MPC onto PTFE films was performed by Ar plasma treatment and grafting polymerization. Surface properties of the modified films were characterized by ATR-FTIR, XPS, SCA, SEM, and Antithrombogenicity experiment. The results demonstrated that MPC has been grafted onto PTFE surfaces successfully. The hydrophilicity of the modified surfaces has improved drastically in comparison with that of untreated-PTFE. SCA for the modified PTFE films in the water decreased from 108°to 58.25°and surface energy increased from 17.52mN/m to 45.47mN/m. The effects of plasma-treatment time, MPC monomer concentration, and grafting time on the degree of grafting were determined. As a result, it was found that the condition of plasma power 20W, treatment time 40s, MPC monomer concentration 25wt%, grafting time 24h showed an optimal grafting degree. Experiments of platelet adhesion and thrombogenic time have shown that the platelet adhesion amount on the MPC-grafted PTFE surfaces reduced remarkedly.PLA-PC was synthesized and coated onto PTFE surface. ATR-FTIR, XPS and ~1H-NMR were introduced to confirm its chemical structure. SCA, surface energy and thrombogenic experiment have shown that the hydrophilicity and biocompatibility of PTFE coated with PLA-PC have improved. |
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