Study On Biological Behavior Of Different Modified Coatings On Magnesium-based Surface

Magnesium(Mg)and its alloys are new degradable materials,extensive research has been conducted on bone tissue replacement materials,because of its excellent mechanical properties and degradable properties.However,the high degradation rate of Mg in human body affects the success rate of its transplantation and limits its clinical application.Based on this,Ca PO₃(OH).2H₂O(DCPD)was prepared on the Mg matrix surface as the outer layer,fluorinated silica(FMSNs)containing curcumin and polylactic acid(PLA)was used as the intermediate layer,and micro-arc oxidation(MAO)microporous layer was used as the modified surface layer.Four kinds of coatings were prepared by regulating the content of intermediate layer FMSN,and they were named as 0FMSN,5FMSN,10FMSN and 20FMSN respectively according to the different content of FMSN.The biological properties of the above four coatings were tested in vitro and in vivo,and the following results were obtained:1)Macrophages cultured on the surface of four kinds of coatings for 1,3 and 5days were detected by the Alamar blue method and the live/dead staining method.The macrophages all survived well,indicating that the coatings had good biocompatibility.2)The morphology of macrophages was observed after 1,3 and 5 days of culture on different coating surfaces,and the results showed that macrophages were spherical on 0FMSN,with less diffusion and little change in morphology during incubation.However,when macrophages were incubated on the other three coating surfaces,the cells all continued to unfold with the extension of culture time,and this trend was most obvious on 20FMSN,and finally the cells fully unfolded into a larger polygonal shape.3)Real-Time quantitative PCR(qRT-PCR)results showed that with the extension of incubation time,the four kinds of coating on the surface of the proinflammatory factor TNF-?,IL-1?and i NOS were cut,and anti-inflammatory factor IL-10,ARG and CD206 are raised,that four kinds of coating are can control the macrophages from proinflammatory M1 phenotype to M2 phenotypes,suppression is promoting the immunoregulatory effects of anti-inflammatory,and the degree of regulating follow 0FMSN<5 FMSN<10 FMSN<20 FMSN rule.4)Collect conditioned medium(CCM),with its four kinds of ectomesenchymal stem cells(BMSCs)coating surface culture,alizarin red staining and qRT-PCR results showed that four kinds of coating are favorable to the extracellular matrix mineralization of BMSCs and osteogenetic differentiation,and in line with the 0 FMSN<5 FMSN<10 FMSN<20 FMSN trend,confirmed that the coating has the ability of bone immune regulation,and the ability to promote bone formation increased with the increase of FMSN content increased.5)Micro-CT and bone tissue staining(Picric acid-Fuchsia staining,V-G staining)were used to detect the femur samples implanted in rats for 4 weeks.The results showed that the amount of new bone formation induced by different implants followed the rule of pure Mg<0FMSN<20FMSN,indicating that the 20FMSN coating had the best bone immune regulation and osteogenesis promotion ability.Figure[23]table[5]reference[108]...