Study On Mg-Fe Layered Double Hydroxides Films On Medical Titanium Surface

Titanium and its alloys having good corrosion resistance and good biocompatibility are widely used as hard tissue implants.However,they are bio-inert and no antibacterial characteristics.In this dissertation,layered double hydroxide(LDHs)films with good biocompatibility would be built to modify titanium and its alloys surface.Because magnesium and iron are vital elements for the human body,magnesium-iron layered double hydroxide(Mg-Fe LDHs)films were prepared on pure titanium via hydrothermal process.Respectively,the microstructures of the deposited films were examined and their formation processes were discussed.The effect of Mg-Fe LDHs films on rat bone marrow mesenchymal stem cells(r BMMSCs)and bacteria were tested in vitro.Minocycline hydrochloride was loaded on Mg-Fe LDHs film via immersion method.The release of minocycline hydrochloride and their effect on bacteria and mouse osteoblasts(MC3T3)were explored.The anti-cancer drug 5-fluorouracil was loaded on Mg-Fe LDHs films by structural reconstruction method and the effects of drug release on osteosarcoma cells(MG63)were investigated.The main results obtained described as follows:1.Magnesium hydroxide(Mg(OH)2)film and Mg-Fe LDHs films with different Mg/Fe(atom ratios)were prepared on the surface of pure biomedical titanium substrates by the hydrothermal methods.The results showed that the prepared magnesium hydroxide film was beneficial to the osteogenic differentiation of r BMMSCs and inhibited the growth of E.coli.However,the adhesion and proliferation of r BMMSCs on the surface of Mg(OH)2 film was inferior.The prepared Mg-Fe LDHs films could regulate the p H value of cell-material microenvironment,which significantly improved the cell compatibility and osteoinduction ability of samples surface.However,the prepared Mg-Fe LDHs films were lack of antibacterial ability.2.Minocycline hydrochloride was loaded on Mg-Fe LDHs films by soaking method.The prepared drug-loaded Mg-Fe LDHs films which shown long-lasting release of minocycline hydrochloride exhibited significant inhibition on E.coli and S.aureus(inhibition rate could reach nearly 100%).In addition,the prepared drug-loaded films promoted the adhesion,proliferation,and osteogenic differentiation of MC3T3 cells.3.5-fluorouracil was loaded on the constructed Mg-Fe LDHs films by structural reconstruction method.The drug-loaded Mg-Fe LDHs films with less drug loading were not of anti-tumor effect.