Repair of rabbit articular cartilage defect by a novel injectable bioactive glass scaffold / 中华骨科杂志

ABSTRACT

Objective By comparing different repairing effects of different methods on articular cartilage defects in rabbit model,the ability of a new bioactive glass scaffold to repair cartilage defect was studied.Methods We prepared the PSC/CS bone cement by mixing the bioactive glass (BG) powder composed of 10.8％P205-54.2％SiO2-35％CaO (PSC),chitosan solution (CS) and calcium sulfate hemihydrate (CSH),then the bone cement was sized by a mold to form cylindrical scaffold.In vivo experiment,18 male rabbits were divided into three groups randomly,including blank group,BG group and TGF-β1 group,which was added TGF-β1 into BG scaffold.Both knees of each rabbit were made cartilage defect for the same group,and no intervention was applied in B group,then implanted scaffolds into defects in both experimental groups.At 6 and 12 weeks after surgery,observed the macroscopic growth,histologic staining and collagen Ⅱ immunohistochemistry (IHC),and the International Cartilage Repair Society (ICRS) and Wakitani score were used to analyze the experimental results quantitatively.Results At 6 weeks after surgery,there was no obvious difference between blank group and BG groups,but the macroscopic result of TGF-β1 group was better than the other two groups and its ICRS score 4.67±0.52 points was statistically higher than BG group 2.83±0.75 points (t=-2.817,P=0.015).As to the comparison of histologic staining and Wakitani socre among three groups,no statistical difference was observed (blank group=13.67±0.52,BG group=13.83±0.41,TGF-β1 group=13.33±1.03).At 12 weeks after surgery,there was still no obvious difference between blank and BG groups,while the results of macroscopic observation and ICRS score in TGF-β1 group were significantly higher than them 9.01±0.63 points (blank group vs TGF-β1 groupt=-2.289,P=0.022;BG group vs TGF-β1 groupt=-2.326,P=0.020).More importantly,much deeper positive staining were observed in TGF-β1 group,and the Wakitani score was higher than the other two groups (blank group=9.83 ± 1.33,BG group=9.51 ± 1.05,TGF-β1 group=6.50± 1.38,blank group vs TGF-β 1 groupt=-2.771,P=0.007;BG group vs TGF-β1 groupt=-2.756,P=0.006).By comparing the degree of histologic staining and Col Ⅱ expression with normal cartilage,the regenerated tissue in TGF-β1 group was similar.Conclusion Single PSC/CS scaffold doesn't possess excellent ability to repair cartilage defect.When TGF-β1 was added into PSC/CS bioactive glass,the scaffold was able to promote cartilage defect repair,and the regenerated tissue was similar to normal cartilage.