Experimental Study On Repairing Articular Cartilage Defects Using The Cocultures Of BMSCs And Allogeneic Costal Cartilage Cells Combined With Bone Matrix Gelatin

Objective:The study aims to investigate the feasibility of repairing articular cartilage defects using the coculture of bone mesenchymal stem cells (BMSCs) and allogeneic costal cartilage cells combined with autologous "two-phase" bone matrix gelatin (BMG). Methods:1, Rabbit BMSCs were isolated by the method of adherent centrifugation, and the costal cartilage cells were obtained with the methods of enzyme digestion and tissue explant, followed by in vitro amplification, morphological observation, drawing of growth curve, BMSCs phenotypes detected by flow cytometry and histological identification of cartilage cells.3, The P2generations of the two cells were randomly divided into three groups: Group A was the coculture group; group B was the high concentration of simple cartilage cells group; group C was the low concentration of simple cartilage cells. Two weeks of in vitro culture later, the content of glycosaminoglycan in the medium of each group was measured for the single factor analysis of variance using the statistical software.4, The autologous iliac of rabbit were taken and prepared for the "two-phase" BMG with the improved Urist method.5, The co-cultured cells were attached to the BMG scaffolds and cultured in vitro for3days, and then were observed under the electron microscope.6, The articular cartilage defect models of36New Zealand White rabbits were prepared and randomly divided into three groups:The experimental group was the co-cultured cells-BMG complex implantation group; the control group was the simple BMG implantation group; the blank group was the untreated group. The samples were respectively taken at postoperative1st,2nd and3rd months for the general morphological and histological observation, and then scored for statistical analysis.Results:1, The BMSCs isolated by the method of adherent centrifugation were in good growth, and the costal cartilage cells obtained by the methods of enzyme digestion and tissue explant were with sound biological activity.2, Two weeks later, the content of GAG in the medium of group A was significantly more than those in group B and C, and there was statistical significance between the difference (p<0.05).3, The scanning electron microscope (SEM) showed that BMG was of the porous network-like structure, on the surface of which many cells in good growth were adhered to.4, After three months since the surgery, the cartilage defects in the experimental group were basically repaired, with hyaline cartilages in the repaired tissues; the cartilage defects in the control group and blank group were partly repaired, with fibrous structures in the repaired tissues. The score at each time point in the experimental group was significantly different with those in the blank group and control group (p<0.05), indicating that the remediation effect was better than those in the other two groups.Conclusion:BMSCs were co-cultured with allogeneic costal cartilage cells, which can be induced and differentiated into cartilage cells. There were no any obvious rejective reaction, and the amount of cartilage cells was reduced. The co-cultured cells combined with autologous "two-phase" bone matrix gelatin can effectively repair the articular cartilage defects.