Repair of rabbit knee articular cartilage defect by the injectable chitosan/beta-glycerophosphate gel encapsulating allograft chondrocytes and the intervention of Weilingxian / 中国组织工程研究

ABSTRACT

BACKGROUND: At present, studies on repair of cartilage defect have been focused on tissue engineering technique. Growth factors are one of the most important parts. However, the effect and security of growth factors have not been confirmed. Studies have shown that Weilingxian can maintain and promote the synthesis of proteoglycan, collagen Ⅱof chondrocyte, and it also can promote proliferation of chondrocyte and expression of transforming growth factor (TGF)-β1 mRNA.OBJEGTIVE To investigate the feasibility of injectable chitosan/β-glycerol phosphate (C/β-GP) encapsulating allograft chondrocytes on the repair of articular cartilage defects and the intervention effect and possible mechanisms of Weilingxian.METHODS: A 0.4-mm defect was established on knee articular cartilage. Expeirmental New Zealand rabbits were randomly divided into three groups Weilingxian, common culture media, and model groups. In the common culture media group, the samples were treated with C/β-GP and chondrocyte suspension (1 mL); at 2 days after gel injection, Weilingxian or common culture media (1 mL) were respectively given into joint cavity, once a day, for 7 successive days. The samples in the model group were not treated. Gross, histological (HE staining, TB staining), type Ⅱ collagen immunohistochemical, and Wakitani score examinations were performed on 6 and 12 weeks after surgery.RESULTS AND CONCLUSION: Defects of articular surface were well filled in Weilingxian and common culture media groups, and hyaline cartilage-like structure was formed. The surface flatness and degree of integration with surrounding tissue of Weilingxian group was better than common culture media group. Formation of cartilage-like and secretion of cartilage matrix and specificity of collagen type Ⅱ were found in histological slices. Defects in the model group were not repaired, while tissue proliferative degeneration was observed. Integration of.repair tissue with surrounding tissue, histology and amount of type Ⅱ collagen secretion in Weilingxian group were better than common culture media group. Wakitani scores of Weilingxian group and common culture media group were significantly lower than model group (P < 0.01), andscores of Weilingxian group was significantly lower than common culture media group (P<0.05). Injectable chitosan/β-glycerolphosphate gel encapsulating allograft chondrocytes could repair articular cartilage defects, and Weilingxian was able to promote the process of it, this manifested the role like growth factor in tissue engineering technique repairing articular cartilage defects.