Fabrication Of HA/MgO Composite Materials And Their Bioactivity In Vitro

Hydroxyapatite(HA)bioceramic materials have been widely used in biomedical fields,such as bone tissue regeneration,cell proliferation,drug delivery and release.However,mechanical properties of the HA is poor.Ti and its alloys due to high corrosion resistance,high mechanical strength and excellent biocompatibility are proverbially used in a variety of bone substitute materials.Therefore,the HA coatings with excellent biocompatibility and mechanical properties on Ti surface have been studied widely.HA-CS-MgO-SiO2,HA-CS-MgO-SrCO3,and HA-CS-MgO-ZnO composite coatings were coated onto titanium substrate by electrophoretic deposition(EPD),and then the HA-MgO-SiO2,HA-MgO-SrCO3,and HA-MgO-ZnO porous composite coatings were obtained by subsequently sintering treatment using chitosan as porogen.The porous composite coatings were characterized by XRD,EDS,FT-IR,Universal Testing Machine,SEM,UV-Vis and CHI Electrochemistry Workstation.And antibacterial properties of the porous composite coatings were studied by Bacillus subtilis and Escherichia coli as probe.HEPES simulated body fluid(H-SBF)was used for evaluation the biological activity of the porous composite coatings in vitro.The results showed that the bonding strength between HA-MgO-SiO2,HA-MgO-SrCO3,and HA-MgO-ZnO porous composite coatings and Ti substrate reached 31.1 MPa,26.4 MPa,and 27.2 MPa,respectively.These porous composite coatings exhibited better corrosion resistance in H-SBF.The average inhibition zone and inhibition rate of the porous composite coatings using Bacillus subtilis as probes were 8.7 mm and 81.5%,9.0 mm and 83.7%,8.3 mm and 80.7%,respectively.The average inhibition zone and the inhibition rate of the porous composite coatings using Escherichia coli as probes were 10.8 mm and 87.3%,9.0 mm and 84.3%,8.0 mm and 83.5%,respectively.These porous composite coatings exhibited well bioactivity in the H-SBF.The HA-MgO-SiO2 porous composite coating is the most comprehensive features,so it is hopeful to develop as implant material for replacement of human bone.