Study On Surface Modification Of Biomedical Polymeric Materials For Antithrombogenicity

Biomedical polymer materials were widely used in biological and medical fields. When the polymer materials were in contact with human body permanently or transiently, they can cause the adverse biological reactions, for example, inflammation, carcinogenesis, forming thrombus and so on. The adverse biological reactions were caused by the action of materials surface and biological environment. Surface modification of polymer materials can enhance its biocompatibility. This paper is related to surface modification of PE films by combining plasma pretreatment with UV-induced graft polymerization, in order to improve the antithrombogenicity of polyethylene (PE) films. Moreover, another work of this paper is the surface modification of biodegradation polymer materials poly(D,L-lactic acid) (PDLLA) by plasma.(1) For improving antithrombogenicity of PE films, the films pretreated by Ar plasma were subjected to UV-induced graft polymerization with acrylamide (AAm) without photo-initiator. Following the AAm-grafted PE films (PE-g-PAAm) were alcoholysised with octadecyl alcohol (PE-g-SPAAm). Effects of plasma composite parameter (W/FM), plasma pretreatment time, AAm monomer concentration and UV irradiation time on grafting yields were investigated systematically. The optimized reaction condition was: W/FM= 0.08~0.10 GJ/kg, plasma pretreatment time = 2 min, AAm monomer concentration = 20 wt.%, UV irradiation time = 30 min. The surface properties and microstructure of PE-g-PAAm and PE-g-SPAAm were studied by contact angle measurement, X-ray photoelectron (XPS), Attenuated Total Reflectance Fourier Transfer Infrared (ATR-FTIR) and Atomic Force Microscope (AFM). It was confirmed that AAm and stearyl group were orderly immobilized successively onto the PE surface. Result of platelet adhesion experiment have shown that antithrombogenicity of modified PE films was improved clearly. The reaction mechanism onto films' modification was presumed. It is think that the tail-like structures were formed on the surface of PE with polyacrylamide as spacers and the stearyl groups as end groups. It is investigated that improvement of...