| Summary: | 碩士 === 國立臺北科技大學 === 化學工程研究所 === 104 === Because 316L stainless steel has good corrosion resistance, non-magnetic property, good biocompatibility and strong mechanical strength, it has been widely used in orthopedic and dental implant. However, there remain many problems in clinical, including incomplete cell attachment, osseo-integration failure, bacterial infection, immun rejection, which ultimately lead to implant failure. In order to solve these clinical problems, a series of surface modification techniques have been developed. In this study, through spin coating technique, we fabricated polyelectrolyte multilayers coatings ( PEMs ) composed of collagen, chitosan barrier and γ-poly-glutamic acid onto 316L stainless steel substrate. Dual growth factors, bone morphogenetic protein 2 ( BMP-2 ) and basic fibroblast growth factor 2 ( FGF-2 ), were added into of near substrate part and near bone part respectively. During the process of bone defect restoration, FGF-2 was released first and then BMP-2. The experimental results showed that the PEMs coating helped the sustained release of growth factor up to 48 days. The PEMs coating presented good biocompatibility. In vitro study using mouse bone marrow mesenchymal stem cells was carried out, and the results of fluorescent staining, alkaline phosphatase measurement and calcium deposits staining showed that the osteogenic differentiation trend was more significant for multilayers with dual growth factor group. At day 21, significant calcium deposition was quantified, which indicated that stem cells significantly intended to mineralization. In hemolysis test, the coating was slightly hemolytic. We implanted the coated substrates into the skullcap defects of mouse, and the results showed that bony tissue would directly grow onto the coatings. There were two times of new bone formation for the samples of PEMs coating with growth factor comparing to without ones. The PEMs coating was a promising way for surface modification and drug controlled release.
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