| Titanium has been widely used to manufacture clinical implants owing to its lightweight, non-toxic, good biocompatibility and elastic modulus close to human bones. However, titanium cannot bone-bond with bone tissue and was thought to be bioinert. Thus, implantation is easy to loose or even fall off. In order to improve the bond strength between the titanium and the surrounding bone tissue, chemical surface modification is a very effective method of activation treatment on titanium surfaces.In this paper, titanium was first soaked in sodium hydroxide solution by alkali-heat treatment. And then the titanium surface was silanization with3-aminopropyltriethoxysilane(APTES). Scanning electron microscope(SEM), attenuated total internal reflectance fourier transform infrared spectroscopy(ATR-FTIR), X-ray photoelectron spectroscopy(XPS) were employed to investigate the surface morphology and composition of the titanium. The growing mechanism of the apatite layer on silanized titanium surface was studied by immersion the silanized titanium samples in a simulated body fluid(SBF) for the biomimetic deposition. The biocompatibility and bioactivity of the silanized titanium were also investigated by in vitro cell culture. The results revealed:three dimensional porous structure was formed after the alkali solution treatment for48h under80℃; APTES was successfully grafted on Ti surface, remaining three dimensional porous structure; The amino group of the silanized titanium surface as well as the porous structure exhibited good apatite-inducing ability in SBF. The bone-like apatite crystals formed on silanized titanium surface after immersing in2SBF for7d better mineralization. When co-cultured with human sweat gland cells(HMSCs), the results showed that the porous structure and surface chemical group have obvious impacts on cell. And it can promote the adhesion, proliferation and differentiation of HMSCs.In this paper, gelatin was modified by methacrylic anhydride(MA) and synthesized gelatin methacrylate(GELMA).The effect of reaction time and MA concentration on the substitution degree(DS) of gelatin was investigated. And GelMA coating was constructed on silanized titanium surface by UV-irradiation. Scanning electron microscope(SEM), fourier transform infrared spectroscopy(FTIR), hydrogen nuclear magnetic resonance spectra(HNMR) were employed to investigate the surface morphology and composition of GelMA and GelMA hydrogel coating. The results showed that the DS value increased with increasing reaction time and MA concentration. GelMA hydrogel coating was successfully constructed on the silanized titanium surface by UV-irradiation, and the diameter the GelMA hydrogel microporous is5-10μm.Bovine serum albumin(BSA) was used as a protein model to discuss the protein adsorption and release properties on pure titanium, alkali-heat treatment titanium, silanized titanium and GelMA-coated titanium samples. Qualitative and quantitative analysis of BSA adsorption was assessed by microplate reader, fluorescence microscopy and ATR-FTIR techniques. The results indicated the maximum protein adsorption of GelMA-coated titanium samples occured at the concentration of1.5mg/ml. The increase in the protein concentrations over1.5mg/ml lead to no longer protein adsorption increase. In addition, the amount of BSA adsorbed on GelMA-coated titanium is the most, followed by alkali-heat treatment titanium and silanized titanium samples, and the pure titanium is the least. After releasing for24h, BSA release rate reached80%for pure titanium samples, followed by alkali-heat treatment titanium and silanized titanium. GelMA-coated titanium has the minimum release rate of only6%. All the results show that titanium modified by GelMA hydrygel coating will be promising to be used as bone tissue engineering scaffold or bone defects repairment materials. |
PDF Full Text Request