Research Of Non-canonical Wnt Pathways Regulated By Implant Tricalcium Phosphate Microstructure

Objective:By using foaming function of H₂O₂ and controlling the sintering temperature to prepare different microstructures of TCP ceramic materials,then to explore the influence of different microstructures of TCP materials on the expression levels of related markers in Wnt non-canonical signaling pathway.1 Clay body is produced by the prepared slurry with the hydrogen peroxide.The formed clay body is sintered at 1080°C.and 1000°C.to obtain a tricalcium phosphate porcelain with different microstructures,named TCP-compact?TCP-middle and TCP-big.3 The chemical composition of the formed ceramic material block was verified by XRD experiment.2 The SEM confirmed the surface morphology and particle size of the prepared material.3 Mercury injection experiments to determine the internal structure of the material,including the average pore size,porosity,tortuosity,etc.4 MG63 cells were co-cultured with different microstructures of TCP materials,and cultured plates were used as blank control.The expression levels of Wnt5a,Wnt11,ROR2,FZD1,and DKK1 in each group were detected by q-PCR.in 3,5,and7 days.Results:1 XRD results:The chemical composition of the three implantable ceramic materials prepared in the experiment was?-TCP?Figure 3-1?.2 SEM results:Under the scanning electron microscope,the surface pores of TCP-compact were smaller and the number was less.However,the surface of TCP-middle and TCP-big was obvious roughly,and the gully pattern was evidently?Figure 3-2?3 MIP results:The porosity of TCP-compact is about 34.11±1.04%and the pore size is about 0.96±0.04?m.The porosity of TCP-middle is similar to that of TCP-big,but the pore size is different,the distribution is 6.51±0.30?m,10.41±0.67?m.?Table3-3?.4.Expression of Wnt5a:The expression level of Wnt5a in materials with micropore structure increased significantly?P<0.05?.The expression level of Wnt5a was highest in materials with larger pore size.There was no difference between material group and the control in the late stage of co-culture?P>0.05?.5 Expression of Wnt11:Wnt11 expression in TCP-middle group was lower than that in Control group?P<0.05?and this low level was alleviated but still lower than that of the control group in the later period.Initially,the TCP-middle group`s expression was inhibited but it showed mild promotion in the later period.TCP-big showed an early release from the inhibition state and showed improvement on the 5<sup>t</sup>hh day.Simultaneously,it was also observed that the expression levels among the material groups were different at different time points?P<0.05?.6 Expression of ROR2:TCP-compact showed a low level of ROR2 expression compared with the Control group?P<0.05?.The materials with micropore structure showed difference but not obviously in early time and increased significantly in the5th day?P<0.05?.What`s more,TCP-big co-cultured with MG63 was more effective in promoting the expression of ROR2?P<0.05?.7 Expression of FZD1:The initial expression of FZD1 in TCP materials were lower than that in control group.On the 5th day,the expression of FZDI in materials group with micropore structure increased and microporous material with larger pore size.got more positive significance?P<0.05?.8 Expression of DKK1:When compared with control group,material with microstructure promoting the expression of DKK1.TCP-middle significantly promoted DKK1 expression in the early stage,and this effect was weakened and the amplitude was larger with time.The performance of the TCP-big group is similar to that of the TCP-middle group,but the difference lies in the small change.While material without microstructure showed the inhibition all the time.On the 7th day of co-culture,there was no significant difference in material group expression?P>0.05?.Conclusion:TCP materials with different microstructures were prepared by hydrogen peroxide foaming and controlling the sintering temperature.Secondly,the co-culture of TCP material with MG63 cells showed that the material affected the expression level of Wnt non-canonical signaling pathway.The difference in expression level of Wnt non-classical signal pathway was regulated by the micropore structure of the material.In a certain rang,it was significantly promoted by the big pore size of tricalcium phosphate porcelain with microstructure.The TCP material with micropore structure can initiate osteoinduction by promoting the expression of Wnt non-canonical signal pathway.