| Objective: To study the application prospect of GO/PMMA in osteoporotic vertebral compression fracture Materials and methods:GO / PMMA Mechanical properties: The diameter tensile and compressive capacities of Calcium sulfate ?PMMA and GO / PMMA composite scaffold were measured using a universal material testing machine.GO / PMMA cytological characteristics: The morphology of hBMSCs on the surface of PMMA and GO / PMMA composites was observed by SEM to evaluate cell adhesion and morphology.The feasibility of hBMSc grown in GO / PMMA conditioned medium was determined by XTT to study the cell compatibility of GO / PMMA discs.The cell differentiation was assessed by the degree of ALP activity in HBMSc cultured in GO / PMMA conditioned osteogenic medium.TolBlue and TRAP stained sections were viewed under a Nikon SMZ800 stereomicroscope.Bone affinity index(AI)was calculated by measuring the percentage of the implant perimeter that was in direct contact with bone using ImageJ.Analysis of the TRAP stained sections was conducted using Photoshop Elements 2.0.The implant and an area of surrounding bone up to 1.5 mm distance from the implant in each direction was selected and,within this selection,red pixels,which were indicative of TRAP activity,were quantified.Data processing:Statistical analyses were performed with SPSS 22.One-wayanalysis of variance(ANOVA)with the post hocTukey-Kramer multiple-range tests wereperformed to determine the statistical significance of the differences among two or more groups.If sample sizes were not consistent pair-wise comparisons were carried out using Gabriel's procedure.Significance level was set at p < 0.05.Results:The repeated experiments and statistical analysis of each group of materials showed that the strength of GO / PMMA composites changed with the change of GO mass fraction in a certain range,and when the GO reached 1.5wt%,the tensile strength reached the maximum and significantly better than PMMA group and the compressive strength was the lowest but higher than that of the calcium sulfate group.The cytological characteristics of all GO / PMMA composites were significantly better than those of PMMA.Scanning electron microscopy revealed that the morphology and adhesion of hBMSC were the best when the GO mass ratio was 1.0 wt%,and the morphology and adhesion were lower than 1.0 wt% or higher than 0.5 wt% hBMSC.The XTT assay showed that the cell compatibility was the highest when the GO mass ratio was 1.5 wt%,and the cell compatibility was lower or lower than that of the PMMA group at or below 1.5 wt%.The degree of ALP activity in HBMSc cultured in GO / PMMA conditional osteogenic medium showed that the ALP activity increased with the increase of GO mass ratio,and the ALP activity reached the highest when the GO ratio reached 2.5wt%.Overall,the AI value of the GO / PMMA group was higher than that of the PMMA group.After implantation for 5 weeks,the mean AI was about 180% higher in GO / PMMA than in the PMMA group.After implantation for 10 weeks,the mean AI of the GO / PMMA group was 400% higher than that of the PMMA group.Nonetheless,relatively large changes within the group resulted in almost no statistically significant differences.Significant differences in AI were observed between GO / PMMA formulations after 5 weeks of implantation.However,GO / PMMA showed an average AI significantly higher than PMMA(P = 0.01).There was no significant difference between the AI values of the GO / PMMA formulation after 10 weeks of implantation.In addition,no significant increase in AI was observed between 5 and 10 weeks of implantation for each implant type.Conclusion:The experimental results show that the tensile strength of GO / PMMA is better than that of PMMA and the compressive strength of PMMA is decreased.The results show that the addition of GO can significantly improve the mechanical properties of PMMA,and the biological properties of GO / PMMA are also better than PMMA,It is proved that GO / PMMA has a good prospect in future osteoporotic vertebral compression fractures. |
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