Bioactive Glass Ceramic Coating Promotes Osteoblast Proliferation And Differentiation Through Hedgehog/Smo/Gli1 Signaling Pathway

Background:With the continuous development of bioengineering technology,Bioactive glass ceramics plays an important role in promoting bone growth and reconstruction.Hedgehog/Smo/Gli1 signaling pathway as an important regulatory signal pathway for bone development and growth,However,there is no research on the mechanism of action between bioactive glass ceramics and Hedgehog/Smo/Glil signaling pathway.Objective:To explore the mechanism of bioactive glass ceramics promote bone bone marrow stem cells formation through Hedgehog/Smo/Gli1 signaling pathway.Method:1.The preparation of bioactive glass ceramics coating was achieved by high temperature melting method,and observed by scanning electron microscopy and transmission electron microscopy.2.The bone marrow mesenchymal stem cells were extracted,purified and cultured,then seeded on the bioactive glass ceramic coating.RT-PCR,western blotting and immunofluorescence staining were used to assess the proliferating cell antigen ki-67 and BMP2、Osteocalcin、ALP、Runx2、Gli、Smo mRNA expression and protein production,respectively.3.To further observation Gli、Smo mRNA expression and protein production after using the Hedgehog signaling pathway antagonist Cyclopamine.Result:1.Scanning electron microscope showed that the surface of coating was smooth,no crack(Fig 1 A).Transmission electron microscope showed that the surface of coating was in a grained form with nano-scale mesopore(Fig 1B).The thickness of BGC coating is about 350nm。The coating conforms to the three-dimensional porous structure,which is conducive to the growth of seed cells in tissue engineering.2.Bone marrow mesenchymal stem cells showed homogeneous shuttle type after cell passage.3.The distribution of ki-67 positive cells in the bioactive glassy ceramic group and the control group can be seen,while the number of cells in bioactive glass-ceramic group was significantly higher than that in control group.Expression of Glil、Smo、BMP2、Osteocalcin、ALP、Runx2 mRNA and protein increases in bioactive glassy ceramic group.4.The level of Gli1 and Smo mRNA in bioactive glass-ceramic group decreased more obviously after adding inhibitors of Hedgehog pathway.conclusion:1.The coating conforms to the three-dimensional porous structure,which is conducive to the growth of seed cells in tissue engineering.2.Bioactive glass ceramic coating improves the expression of BMP2,Osteocalcin,ALP,Runx2 and other protein genes through Hedgehog/Smo/Gli1 signaling pathway to promote osteoblast formation.