Medical Metal Surface Plasmon Polyolefin Propylamine Films And Anticoagulant Molecules Fixed

When medical metal biomaterial is contacted with blood,its hemocompatibility is the basic matter. However,the properties of these metal materials which is contacted with blood for longterm is far from the criterion of the clinical use. Albumin and PEG is used for surface modification of medical polymers to improve its hemocompatibility. But on account of little functional group on the surface of metal biomaterials,it is hardly possible to immobilize albumin and PEG molecule.Therefore,how to form a relatively high concentration of the reactive functional group onto metal material surface via surface treatment and effectively immobilize albumin and PEG molecule through the functional group to improve the anticoagulant property of metal biomaterial surface has become the cruces of the research.In this paper, 316L stainless steel is chosen as research object. A series of Poly-Allylamine films is fabricated on stainless steel using pulsed radio frequency plasma polymerization technique of different aggradation powers. Subsequently, vacuum heat-treatment is treated to the film. Through contact angle measurement, fourier transformation infrared (FTIR) , X-ray photoelectron spectroscopy and atomic force microscopy(AFM) analyse, it shows that the hydrophilicity of the Poly-Allylamine films descend after vacuum heat-treatment. Poly-Allylamine films with a power of 30W can preferably retain the configuration of former monomer and NH2/C of the film descends from 2.27% to 1.95% before and after vacuum heat-treatment. Furthermore, RMS of the film is also descended from 0.375 nm to 0.298nm before and after vacuum heat-treatment,Which indicates the film is apparently refined. SEM shows that the dynamical stability of the film in water solution is distinctly improved.This paper use NH₂ as reaction site , to graft a series of PEG molecule of various molecular weight to the vacuum heat-treated Poly-Allylamine films through chemical grafting with HMDI. Contact angle measurment results show that the hydrophilicity of the films improved after grafting various molecular weight of PEG. As the molecular weight of PEG increases ,the hydrophilicity of the Poly-Allylamine films are increased at first and then decreased. When the molecular weight of PEG is 6000,the contact angle is the least and the hydrophilicity is the best. FTIR and XPS analyse proves that PEG is successfully grafted onto the surface of Poly-Allylamine films. In-vitro blood platelet adhesion test is held to compare the surface blood anticoagulation of the materials, and the results indicate that Poly-Allylamine films which is modified with PEG improve its hemocompatibility,mroeover PEG with a molecular weight of 6000 has the least platelet adhere and least activate quantity.BSA is immobilized onto the surface of heat-treated Poly-Allylamine films with glutaraldehyde, and that contact angle measurement,FTIR and XPS analyse shows a increase of hydrophilicity.The appearance of amide absorbent apex and S element which is unique to protein shows that BSA is immobilized to the Poly-Allylamine surface. In-vitro blood platelet adhesion test indicates that platelet activation and adherence is apparently restrained. Comparing the in-vitro blood platelet adhesion test results of flims grafted PEG6000 and immobilized BSA, it shows that the anticoagulation property of film immobilized with BSA is preferable.