Laser Cladding SiO₂/rare Earth Composite Gradient Bioceramics Coating And Its Inhibition Effects On The Activity Of Osteoclast

In order to improve the bioactivity of Ca-P bioceramic coatings,gradient bioceramic coatings with different doping amount of SiO₂ were prepared on the surface of medical titanium alloy Ti-6Al-4V by laser cladding technique.The effect of SiO₂ content on the bioactivity of coating and the inhibition of osteoclast activity were studied.The cross section,microstructure,phase,microhardness,the bioactivity of coating and the inhibition of osteoclast activity were examined by means of metallographic microscope,scanning electron microscope?SEM?,X-ray diffraction?XRD?,microhardness analyzer,enzyme standard instrument and inverted fluorescence microscope,respectively.Biological activity and inhibition of osteoclasts were studied.The following conclusions are drawn:?1?The effect of SiO₂ doping on the microstructure and properties of laser cladding bioceramic coating was investigated.The results show that the coating quality is improved with doping of SiO₂,the wide and long cracks and holes in the coating decrease obviously,and the coating with 15%doping content has the least crack.Hardness of coating without doping SiO₂ is the highest and the hardness of coating decreases slightly with doping of SiO₂.The phase of laser cladding bioceramic coating mainly includes CaTiO₃,HA,TiO₂,Ca₂SiO₄,and HA is bioactive phase.?2?The effect of SiO₂ doping on the bioactivity of laser cladding bioceramic coating was investigated.The results showed that after immersion in SBF for two weeks,the HA deposited on the coating increased obviously,which indicated that the bioceramic coating had good bioactivity and the coating with 15%SiO₂ doping produced the most bone-like apatite.Co-culture experiments with osteoblasts in vitro showed that the bioceramic coating doped with SiO₂ had better bioactivity and cytocompatibility,and the coating with 15%SiO₂ doping had the best bioactivity.?3?Because of the doping of rare earth and silica,the bioceramic coating can inhibit the activity of osteoclast.Compared with the bioceramic coating without SiO₂,the doping of SiO₂ enhanced the inhibition of osteoclast precursor cells by the bioceramic coating,and the inhibitory effect was the most obvious when the doping amount of SiO₂ was 15%.