Self-assemble Fabrication Of Bioactive Multiplayer Film And Their Properities

To reduce restenosis rate after the current metal coronary artery stent implanting, the paper trys to fabricate (Polyethylenimine(PEI)/Hyaluronan(HA))_n and (Chitosan (CS)/ Carboxymethyl chitosan(CMC))_n bioactive multilayer film on biomedical 316L stainless steel(316LSS) surface and finally fabricate bioactive multiplayer film loading drug on the surface of metal stent via electrostatic self-assembly. The structure and surface micrograph is analyzed by using small angle X-ray diffraction (SXRD), Atomic force microscopy (AFM), scanning electron microscope (SEM), Fourier Transform Infrared Spectrometer (FT/IR);the corrosion -resistances and stability is investigated by electrochemistry and static degrading experiment and the heamocompatibility of the multilayer film is tested through platelet adhesion experiment.Through the study the following major conclusions can be drawn:1: (PEI/HA)_n bioactive multilayer film is fabricated on biomedical 316LSS surface via electrostatic self-assembly. The thickness of every bilayer of the (PEI/HA)_n bioactive multilayer film is about 14nm. The multilayer film can modify the surface morphology of the 316LSS substrate well, the film coats the mechanical polishing metal suface's nick slowly and the surface roughness descends and the contact angles of HA layer are smaller when the layers increase. The dynamic anodic polarization curve indicates the compact multilayer film on 316LSS by ESA can improve the Ecoor and the Eb, and reduce the ip. In the other word, the multilayer film displays the good corrosive resistance and stability. (PEI/HA)_n multilayer film can reduce the adhesion of the blood platelet and the growth of pseudopod, meliorate the antithrombotic and anticoagulantic ability of the 316LSS surface effectively, and improve the biocompatibility of implanting material.2: The main factors of prepared (CS/CMC)5 bioactive multilayer film on 316L stainless steel surfaces such as the polyelectrolyte solution concentration, adding-ion intensity of polyelectrolyte solution, and the pH value of CMC solution are investigated. The best technology to fabricate (CS/CMC)_n bioactive multilayer film via electrostatic self-assembly is decided. FT/IR spectra indicates that the self-assembly of multilayer film is successful. The (CS/CMC)_n multilayer film can modify the surface morphology of the 316LSS substrate well;"little island" particles arrange uniformizably and compactly on the surface. The corrosion-resistance experiment indicates the compact multilayer film on 316LSS by ESA canimprove the Ecoorand the Eb, and reduce the Ip. The static degrading in the Hank's simulating body liquid for 14 days indicates that the stability of the multilayer film is good. The heamocompatibility experiment indicates (CS/CMC)n multilayer film can reduce the adhesion of the blood platelet and the growth of pseudopod, meliorate the antithrombotic and anticoagulantic ability of 316LSS effectively, and improve the heamocompatibility.3: (CMC/Rg3/CS/Rg3)7CMC/Rg3/CS bioactive multilayer film is fabricated loading drug via electrostatic self-assembly, and the stability and drug releasing principle of the multilayer on stent is investigated. The result indicates that the weight of multilayer film loading drug keeps well-proportioned growth, and the weight of the multilayer film loading drug remains at about 350 fig. The static degrading in the Hank's simulate body liquid for 14 days shows good stability of the multilayer film.The drug releasing curve of the multilayer film loading drug indicates that the drug releasing mode is diffusion and releasing period is about 45 days.