抗坏血酸/聚已酸内酯生物材料修复新西兰白兔软骨缺损

目的 探讨抗坏血酸复合聚已内酯(PCL-AA)生物材料在关节软骨缺损修复过程中的作用.方法 将8只雄性6月龄新西兰白兔完全随机分成3组,每只动物于双侧膝关节股骨膑股关节面制备直径3.5 mm、深3 mm的单纯软骨缺损模型,不钻通骨髓腔.A组:PCL-AA;B组:单纯PCL材料;C组:单纯手术空白对照,其中A、B两组填充材料后加入制备好的纤维蛋白胶(10 μg)和凝血酶原(10 μg)混合物以固定材料,空白对照组制备缺损仅冲洗缝合,不予特殊处理.于术后6周和12周,取材,进行大体观察、HE染色、番红固绿染色、Wakitani修复效果评分以及相关定量分析.结果 6周标本外观上A组修复效果明显优于B组,C组未见软骨缺损修复,边界清楚,中央凹陷明显.A组缺损被白色半透明坚硬组织修复,富有光泽.Wakitani评分A组优于B、C两组(P＜0.05).12周A组番红固绿染色显示软骨修复情况优于6周A组标本.HE染色各组均未见急慢性炎症细胞浸润.新生软骨面积百分数和新生软骨细胞数定量分析提示PCL-AA组均明显大于单纯PCL材料组(P＜0.05),C组未见明显软骨长出.结论 PCL-AA生物材料具有良好的生物相容性,可以有效修复兔关节软骨损伤,可能成为关节软骨损伤治疗新的治疗方法.

Effect of polycaprolactone-ascobic acid scaffold in repairing articular cartilage defects in rabbits

Objective To investigate the effect of polycaprolactone-ascobic acid (PCL-AA) scaffolds in promoting repair of articular cartilage defects in a rabbit model.Methods The cartilage defects (3.5 mm in diameter and 3.0 mm in depth) were created in the trochlear groove of the bilateral knees of eight 6-month-old male New Zealand white rabbits.The rabbit models were then randomized into 3 groups to receive implantation of PCL-AA scaffolds (group A,n=8),implantation of PCL scaffolds without AA (group B,n=5),or no treatment (group C,n=3).In groups A and B,the mixture of fibrin gel (10 μg) and thrombinogen (10 μg) was injected into the defects to fix the scaffolds during the surgery.Histological analyses and quantitative assessments of defect repair were conducted at 6 and 12 weeks after implantation of the scaffold.Results At 6 weeks after scaffold implantation,macroscopic observation showed better filling of the cartilage defects in group A than in group B,while no obvious defect repair was observed in group C.The rabbits in group A showed a significant improvement of the Wakitani score than those in group B (4.05±1.11 vs 7.05±0.98,P＜0.05).HE staining revealed the presence of newly generated cells in and around the PCL-AA scaffolds without inflammatory cells.Safranin O staining showed a significantly greater ECM of the newly regenerated tissue in groups A and B than in group C (P＜0.05),and the volume of the regenerated cartilage and cells was significantly greater in group A than in group B (P＜0.05).Samples harvested at 12 weeks showed more hyalione-like cartilage formation than that at 6 weeks in group A.Conclusion PCL-AA scaffolds have a good biocompatibility and promotes the healing of articular cartilage defects.Adding ascorbic acid into PCL scaffolds better promotes cartilage formation in terms of both quantity and quality of the regenerated tissues.PCL-AA scaffolds can serve as a promising biomaterial to promote the regeneration of articular cartilage using tissue engineering techniques.