The Study Of Bone Marrow Mesenchymal Stem Cells With Plga Repairing Of Kienbock's Disease

Objective:To explore effects of Bone Mesenchymal Stem Cells with PLGA treating end-stage degenerative wrist disorders and subsequent carpal collapse caused by kienbock's disease. The purpose of this study was to investigate whether constructs tissue-engineered from autologous marrow-derived mesenchymal stem cells could be effective for carpal bone reconstruction.Methods:The BMSCs of rabbits were harvest by bone marrow spiration.Adherent cells were selected as BMSCs after the whole marrow was cultured. The passage-three mesenchymal stem cells were loaded onto PLGA (poly lactide-co-glycolide) scaffolds in a concentration of 106 cells/ml, and cultured in chondrogenic medium for 21 days. Collected the tissues for histologic and immunohistochemical analysis.All the rabbits were divided into two groups in random,9 in each group.Total lunate excision was performed in eighteen adult rabbits(thirty-six wrist joints) which weighted from two point five to three kilograms.Group-one rabbits underwent excision and implanted PLGA scaffold. Group-two animals underwent excision followed by implantation of a mesenchymal stem cell-seeded PLGA scaffold that had been preincubated in chondrogenic medium. Tissues were harvested for radiographic and histologic analysis at the time of 6 weeks or 12 weeks after operation.Results:We found the presence of extensive toluidine-blue metachromasia and type-Ⅱcollagen immunohistochemical staining in the tissues which had been cultured in chondrogenic medium for 21 days. In groups one,the lunate space was filled with poorly organized fibrous tissue at the six-week or twelve-week time-point. The lunate space were repaired with cartilaginous tissue in group-two at the six-week time-point. We could find the cells whose morphology were accord with newly formed cartilages and presence of extensive toluidine-blue metachromasia around the cell. We could also find the phenomenon of endochondral ossification and interspersed bone ossicles in some areas. At the twelve-week time-point, as the passage of endochondral ossification, there was abundant bone formation as well as evidence of neovascularization. There was no radiographic evidence of ossification in the group-one, whereas there was radiographic evidence of ossification in all six group-two rabbits at the twelve-week time-point. Significant carpal collapse (a 4.9%±1.9% reduction in the carpometacarpal index, P<0.05) was observed in the group-one animals at six-week time-point. In contrast, the carpal height was maintained in the grouptwo animals. At the twelve-week time-point:the degree of the carpal collapse increased in group-one, while the carpal height decreased very few in group-three.Conclusions:Using BMSCs loaded onto PLGA scaffolds after being cultured in chondrogenic medium for 21 days, it could express the phenotype of cartilaginous. Cartilaginous implants preformed from autologous mesenchymal stem cells seeded onto biodegradable scaffold could prevent carpal collapse by means of the biological substituted regenerated tissue which were formated by the passage of endochondral ossification, and the effects were better than group-one.