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1、上海交通大学医学院 2005 级硕士学位论文BG-nHA gradient coating followed by soaking in the simulated body fluid.The characteristics of gradient coatings prepared by hypotherm sinteringwere evaluated by SEM and XRD. The bond strength between gradientcoatings and Ti was tested using tensile test. The adherence and prol
2、iferationof Saos-2 cells cultured on the nanostructured coating surfaces were observedin vitro. 24 Ti implants with gradient coatings were planted in femoralcondyles of 12 New Zealand rabbits randomly and the untreated Ti implantswith same size were planted as the controls. At 1, 3 and 6 months afte
3、rimplantation, the animals were sacrificed after x-ray examination and thetissue around the implants were taken out for prepare of hard tissue sectionand ground section. Quantity of new bone was measured by tetracyclinefluorescence staining. Von Gieson stained micrographs were used to observethe hea
4、ling, bone deposition and osteointegration at the interface betweenbone and implant.2. Preparation of nanostructured titanium surface by plasticdeformation and observation of the surface properties and thebiocompatibilityMedical Ti sheets(10 mm10 mm1 mm) were subjected to plasticdeformation under th
5、e certain condition for different time.The plastic deformation materials were divided into three groups:group (30 minutes, n=6), group(60 minutes, n=6) and group (90minutes, n=6), according to the time of preparation. The characteristics of上海交通大学医学院 2005 级硕士学位论文plastic deformation material were eval
6、uated by SEM, TEM, XRD, CLSMand DMA. The untreated titanium was used as control group. Saos-2 cell linewas cultured on the different titanium surfaces. The features of titaniumsurface and the effects of nanostructured titanium surfaces on cell adherence,proliferation and shape were examined using fl
7、uorescence microscope,LSCM and MTT testing. RT-PCR was used to assess the alteration of BMP-4gene expression. ANOVA was performed using SAS6.0 software package.RESULT:1. The gradient coatings were porous and its surface were composed ofirregular rod-like nano-HA crystals with the diameters smaller t
8、han 100nm.The interface between the coatings and Ti was dense and no cracks werefound. The bond strength was 35.53.5 MPa between coating and Ti. Cellularadherence and proliferation of Saos-2 cells were better on the surfaces withgradient coatings than on untreated Ti surface. Animal studies showed w
9、ellestabilished osteointegration between implants after gradient coatings andsurround bone and amount of new bone were found around implants.2. The stainless steel balls of 8 mm in diameter were used and thevibration frequency was 50 Hz. The plastic deformation was conducted atroom temperature and i
10、n vacuum for 30, 60 and 90 minutes on each surface.After plastic deformation for 3090 minutes, the surface roughness is 10100m. Micropores and crystal particles of 30100 nm in diameter weredetected in the larger pores. XRD data showed the broadening and weak上海交通大学医学院 2005 级硕士学位论文peaks. The elastic m
11、odule decreased by 20 percent. Plastic deformation for60 and 90 minutes yielded good nanostructured titanium surface. Thenanostructured titanium surface promoted Saos-2 cell adherence (P 0.05).Group (60 minutes) had more extensive spreading on titanium surfacesthan the control group. All experimenta
12、l groups had actin filaments alignedalong the major axis of the cells. Group (60 minutes) and group (90minutes) had higher BMP-4 gene expression in Saos-2 cells than controlgroup(P0.05).CONCLUSIONS:Either gradient coatings or plastic deformation canyield nanostructured pure titanium surface which ca
13、n obviously promoted theadherence and proliferation of osteoblast like cells. Osteointegration of theimplant was enhanced by nanostructured surface prepared by gradientcoatings. The results suggested that surface nanometer influence couldenhance biocompatibilty of pure titanium and may become a nove
14、l surfacemodification method for Ti material.KEY WORDS: Nano, Biocompatibility, Hydroxyapatite, Bioactive glass,Gradient coating, Plastic deformation上海交通大学医学院 2005 级硕士研究生学位论文缩略语表缩 写XRDAOBSASEMBGHADMEMDAPIEBEDTAMTTFBSFMTiPBSDMSORGDTEM英文全称X-ray DiffractionAcridine OrangeBovine Serum AlbuminScanning Electronic MicroscopeBioactive GlassHydroxyapatiteDulbeccos Modified Eagles MediumDiamidino-Phenyl-IndoleEthylene BrominationEthylenediamine Tetraacetic AcidMethyl Thiazolyl TetrazoliumFetal Bovine SerumFluorescent MicroscopeTitaniumPhosphate Buffered SalineDimethyl SulphoxideArg-Gly-Asp