Experimental Study On The Effect Of BMP-2 On Repairing Articular Cartilage Defects By Chondrocyte-Improved Fibrin Glue Bracket In Rabbits

Objective: To study the effects of BMP-2 on repairing defects of articular cartilage,BMP-2 were added into stabilized fibrin-chondrocyte constructs. The stabilizedfibrin-chondrocyte constructs were fibrin glue which were added in aprotinin andtranexamic acid. The stabilized fibrin-chondrocyte constructs with BMP-2 werecultivated in vitro and observed the procedure of degradation and the growth ofchondrocytes. Methods: 1. The chondrocytes from articular cartilage of 3 weeks oldNew Zealand rabbit were isolated and monolayer were cultured, then the culturedchondrocytes were seeded on the stabilized FG scaffold with BMP-2 or not. Thestabilized fibrin-chondrocyte constructs cultured and amplified for 2 weeks infour-dimensional spatial in vitro. Histological and electron microscopy were used tostudy the behavior of chondrocytes cultured with fibrin glue. The degradated speeds offibrin-chondrocyte constructs were evaluated in different periods. 2. Two defects ofarticular cartilage were made in the trochlear groove of each rabbit. The defect of groupA was filled with stabilized fibrin-chondrocyte constructs that had BMP-2 and that ofgroup B was filled with the stabilized fibrin-chondrocyte constructs. The defect of groupC was filled with stabilized FG scaffold. The group D was left empty. The repaired ofdefects were periodically examined grossly and histologically. Result: l.The cellmultiplication time of the pure cytoskeleton group spends 4.7 days. The cellmultiplication time of the bone morphogenic protein-2 group is 4.5 days, its growthspeed is quicker than the speed of another.2.Two weeks postoperatively, implantedcartilage blocks could be seen in all experiment groups. The borders were identifiedclearly and all implanted blocks haven't confluenced with circumference. No implantedblock left in the joint cavity .A little extravasated blood could be found in the group D .3.Six weeks postoperatively. untypical hyaline cartilage could be found in the bonemorphogenic protein-2 group and there were much more cartilage cells arrayed regularly.The newly born cartilage has plenty toluidine blue staining male matrix, and fewlymphocyte cells could be seen in some areas. The depth of all the blocks reach as2/3-3/4 high as normal articular cartilage. Their surface were smooth. This phenomenacould also be seen hi the group B. Untypical hyaline cartilage could also be seen in thegroup B. Compared with the group A, the depth of group B is only as 1/2-2/3 high as the normal cartilage. The newly born cartilage of the group B had less toluidine blue staining male matrix than the group A; and the cartilage cells arrayed less regularly. But its surface was smooth too. In the group B, fibrous tissue covered defected areas, the surface of which looked uneven and the borders were identified clearly. In the group D, the defected areas were covered by a thin sheet tissue mainly composed of fibrous scar and imflammation tissue. 4. Twelve weeks postoperatively, the implanted blocks in the group A had tightly integration with vicinity cartilage, the defects of which were also as high as normal cartilage. The newly born cartilage had nearly the same texture as the normal cartilage. The superficial layer cartilage cells had oval shape and the cartilage cells' major axis parallel with articular surface. 5.According to the Wakitani's standard, the group A has the best plerosis effect on the repairing of articular cartilage defect compared with the other groups. It had been proved to have the significantly difference from all the control groups by statistics disposal. Conclusion: l.In vitro, the cell multiplication time of the group A is shorter than the group B. 2.BMP-2 could not only promote the differentiation of cartilage cells but also promote secrete of extracellular matrix.3. BMP-2 applied to stabilized fibrin glue constructs can significantly accelerate the construction of compound and reparation of articular carti...