Repair Of Diabetic Alveolar Bone Defects With Bone Fragments And 3D Printed New Bone Tissue Materials And Its Mechanism

In recent years,the prevalence of diabetes mellitus has increased dramatically worldwide.Alveolar bone defect caused by diabetes mellitus has also increased year by year.Diabetic osteoporosis not only affects the function of teeth,but also affects the restoration or implantation of dentures.Clinical data show that alveolar bone in edentulous area of diabetic patients often accompanied with osteoporosis,bone defect,softening and other pathological changes.Therefore,promoting the repair of bone damage has been a hot topic in the field of tissue engineering.Bone tissue engineering technology is a new potential method for repairing bone defect,which is to isolate the body cells and then inoculate them into the scaffolds after in vitro expansion and culture,and add growth factors to promote bone formation.Rhizoma Drynariae is the main medicine commonly used in orthopaedics and traumatology prescriptions of traditional Chinese medicine.It has the effect of promoting fracture healing and strengthening bone and kidney.In this study,the porous 3D activated scaffold of sodium alginate/hydroxyapatite hydrogel combined with heme oxygenase-1(HO-1)was constructed by three-dimensional printing technology.The surface morphology of the scaffold and its effect on the growth and adhesion of bone marrow mesenchymal stem cells(BMSCs)were observed by scanning electron microscopy(SEM).Real-time PCR and Western B were used by adding animal serum fed with the decoction of Rhizoma Drynariae.Many modern molecular biological methods,such as lot,Elisa,CCK8 and flow cytometry,were used to analyze and explore their roles and possible mechanisms in the proliferation,apoptosis,migration and osteogenic differentiation of BMSCs.The experimental groups were control group,Rhizoma Drynariae(RD)group,Rhizoma Drynariae(RD)+HO-1 group,Rhizoma Drynariae(RD)+HO-1+3D scaffold group.The results showed that porous and irregular distribution of 3-D printed fibrous tissue materials could be observed under scanning electron microscopy.Mesenchymal stem cells grew well in 3-D scaffolds,and their cell morphology was spindle-shaped.Polyhedral villi adhered to the pore of 3-D scaffolds.The expression of HO-1 in transfected pcDNA-3.1-HO-1 cells increased significantly at the level of mRNA and protein.Compared with the high-sugar control group and RD group,the expression of HO-1 in transfected p Compared with the other three groups,RD+H+3D group had the strongest proliferation and migration ability and the smallest apoptotic rate.In addition,in RD+H+3D group,the ratio of TIMP-l/MMP-1,Bax/Bcl-2 was significantly reduced,and ALP,BMP-1,OCN,OPN and OPG were significantly decreased.The protein expression increased significantly(P<0.05).This suggests that the combination of Rhizoma Drynariae and HO-1 can promote the anti-hyperglycemic injury,promote the migration of mesenchymal stem cells by adjusting the ratio of TIMP-1/MMP-1,reduce the proportion of Bcl-2/Bax,inhibit the apoptosis of mesenchymal stem cells,and up-regulate the expression of osteogenic factors such as ALP,BMP,OCN,OPN and OPG in mesenchymal stem cells,thereby promoting the regeneration of diabetic bone injury and accelerating the healing of bone tissue.3D stem cell tissue engineering technology has great significance in the treatment of diabetic alveolar bone repair.