Biocompatibility And Osteogenesis Of Zinc-Containing Silicocarnotite Bioceramic Scaffolds

Objective1.This study is to prepare the composite scaffolds with different mass fractions of Zn O/CPS,including 1%,3% and 5%.2.The scaffolds with 0% Zn content and 1%,3% Zn O/CPS content were detected by in vitro experiments.The cytocompatibility,cytotoxicity of 5% scaffolds and whether bone marrow mesenchymal stem cells(BMSCs)differ in scaffold adhesion,proliferation and osteogenic differentiation are different.3.Four groups of ceramic scaffolds were implanted into rat skull defect models,and the bone defect repair ability of the four groups of scaffolds was compared at two time points,6 and 12 weeks after surgery.Methods1.Calcium silicate powder was prepared by sol gel method,and Zn/CPS bioceramics were prepared by adding different mass fractions of Zn.2.Extract,isolate and culture primary rat bone marrow mesenchymal stem cells(BMSCs),CCK-8 test to detect the cell compatibility of BMSCs on the four groups of bioactive ceramic scaffolds,cell immunofluorescence staining experiment and electron microscopy observation to visually compare the adhesion effect of BMSCs on the four groups of bioactive ceramic scaffolds,by measuring the BMSCs and the four groups of bioactive ceramic scaffolds after co-culture for different periods of time.Absorbance values were used to compare the proliferation ability of BMSCs promoted by four groups of scaffolds.The expression of ALP,RUNX-2,BMP-2,OPN,OCN and other genes related to osteogenesis after BMSCs were co-cultured with four groups of bioactive ceramic scaffolds for different periods of time was measured by q RT-PCR to determine the ability of scaffolds to promote osteogenic differentiation of BMSCs.3.The osteogenic capacity of four groups of bioactive ceramic scaffolds implanted into rat skull bone defect model was measured.Samples were taken at 6 and 12 weeks respectively,and new bone was measured by three-dimensional reconstruction after micro-CT scanning.Some specimens were decalcified and paraffin sections were prepared.Another part of specimens were embedded and hard tissue sections were prepared.The ability of four groups of different scaffolds to promote osteogenesis in vivo was visually observed by HE staining and Van-Gieson staining.Results1.Zn/CPS ceramics with different mass fractions can be successfully prepared by controlling the calcination temperature and time.2.The primary r BMSCs were successfully extracted,isolated and cultured,and the cells grew well after passage.The results of CCK-8 test showed that the four groups of bioactive ceramic scaffolds had good cytocompatibility without obvious cytotoxicity(P > 0.05).Scanning electron microscopy showed that r BMSCs implanted on the scaffold surface 7 days later,the four groups of cells adhered and spread well on the scaffold surface.The results of immunofluorescence staining showed that r BMSCs adhered to the scaffold surface in 0Zn/CPS group,1Zn/CPS group,3Zn/CPS group,5Zn/CPS group.And the better the adhesion results with the increase of Zn content,the fastest growth rate and the largest number of r BMSCs in 5Zn/CPS group.The results of q RT-PCR showed that all four groups of scaffolds had the ability to promote the differentiation of r BMSCs into osteoblasts,but the 5Zn/CPS group had the highest expression of osteogenesis-related genes at 7 and 14 days(P < 0.05).3.Stent implantation was successful in the four groups.Micro-CT scans showed that at 6 and 12 weeks,the speed and amount of induced osteogenesis of the scaffolds in the Zn-containing group were greater than those in the CPS group alone,and the 5Zn/CPS group had the fastest and most amount of scaffolds.VG staining showed that red callus surrounded the scaffold at 6 weeks,and a small amount of new bone tissue appeared in the center of the scaffold.At 12 weeks,the content of new bone tissue in the 5Zn/CPS group was the highest,while a large number of new bone tissue grew in the center of the scaffold,and the material inside the scaffold was degraded.The braided bone and lamellar bone tissue were visible,while the effect of the other groups was not achieved.Conclusion1.The Zn/CPS bioactive ceramics with different mass fractions can be prepared by controlling the temperature and time.2.The biocompatibility test results of the four groups of scaffolds showed that they had no obvious cytotoxicity and good cell adhesion ability.The proliferation of cells also showed a good state over time.At the same time,the four groups of scaffolds had different degrees of ability to promote osteogenic differentiation.The 5Zn/CPS group had the strongest ability and the best effect.3.The CPS scaffold added with Zn can accelerate the osteogenesis effect of the body.Micro-CT results show that 5Zn/CPS has the fastest bone composition speed and the largest amount.The experimental results show that the 5Zn/CPS scaffold has the best bone defect repair ability and effect.