| Biomaterials are kinds of functional materials which are directly contacted with body. They can be served as diagnosis, treatment, rehabilitation and replacement. Therefore, during the course of using, it is particularly emphasized on biocompatibility and resistance to biological aging. Titanium (Ti) metal and its alloys have been widely used as orthopedic and dental implants due to their high fracture toughness and good biocompatibility. However, titanium, being bioinert, cannot directly bond to bone. It becomes encapsulated by a fibrous tissue that isolates it from the surrounding bone after implantation into the living body. Titanate is an extremely important inorganic non-metallic material, and now already is widely used in light catalysis, sensors and electronics and other fields. Due to the good biocompatibility of titanate, bioinert metal titanium and titanium alloy implants can be modified by coating a biologically active MTiO3 (Ca?Sr) layer on their surfaces. A simple hydrothermal treatment method was used to synthesize MTiO3 coatings on titanium alloys in this work. Moreover, antibacterial agent was introduced to improve the titanium's medical application function. Also, a drug delivery system that connected porous titanium bar with hydrogel was obtained and its biomedical performance was studied in this paper.Firstly, CaTiO3 coatings on the surface of medical titanium screws were synthesized by in-situ hydrothermal treatment. The obtained coatings were characterized by SEM, EDS and XRD.And we evaluated the titanium's biological properties by both cell experiment and animal experiment. The results of cell experiments in vitro indicate that the modified titanium screws are more conducive to cell attachment and proliferation than the ones without any treatment. The results of animal experiments in vivo reveal that the modified titanium screws possessed better biocompatibility than the ones without any treatment. The results of in vitro and in vivo experiments showed that the modified titanium by the present method got obviously improved biocompatibility. Moreover, the optimal parameters were confirmed by controlling the synthesis conditions, such as temperature, treatment time and solution composition. The results showed that the optimum treatment time and temperature were 4 h and 110? respectively. The optimum concentration of NaOH and Ca(CH3COO)2H2O were 1 M and 0.04 M.Secondly, SrTiO3 coatings were synthesized by a hydrothermal method. Also, the optimal parameters were confirmed by controlling the synthesis conditions. Similar to the results synthesized CaTiO3 coatings, the optimum treatment time and temperature also were 4 h and 110? respectively. And the optimum concentration of NaOH and Ca(CH3COO)2H2O were 1 M and 0.02 M. Then, Ag and chitosan as antibacterial agent were introduced to titanium substrate, and the modified titanium samples' antibacterial properties were systematically investigated. The results showed that titanium substrates have good antibacterial properties after the antibacterial agent introduced by one-step method accompanied the hydrothermal process or immersed in AgNO3 and chitosan solution respectively. However, the titanium sample immersed in chitosan solution didn't have antibacterial property.Thirdly, the 3D Printers was used to fabrication of porous titanium rod. Porous titanium structures were manufactured from titanium powders using the electron beam melting technology. And the obtained porous titanium rod's porosity was about 50%. Then, hydrogel with high water-absorbing quality was synthesized. A drug delivery system of gentamicin sulfate (GS) that connected porous titanium bar with hydrogel was obtained. The release properties in vitro were studied by UV-Vis absorption spectra. The cumulative release percentage of the drug delivery system for GS was 53.66% in vitro. |
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