Experimental Study Of Osteogenic Ability Of Rabbit Bone Marrow Stromal Stem Cells Loading Onto Material Of Natural Bone

Objective: To construct tissue engineered bone with rabbit bone marrow stromal stem cells which grow in a specific culture fluid and homologous material of natural bone,to study the osteogenic capacity of the tissue engineered bone to repair bone defects in rabbit.Methods: Bone marrow harvested from the bone shaft of femurs of a two- month-old New Zealand white rabbit were applied to density gradient centrifugation to isolate BMSCs. Then the cells were culture-expanded in DMEM plus 10% fetal bovine serum. AT the second passage, the BMSCs were cultured under the condition of induction and differentiated in vitro.The expressions of alkaline phosphatase (ALP) and type I collagen as well as the formation of calcium nodules were detected.The cultured BMSCs were collected and marked by 5-Bromo-dexyouridine(BrdU). Eventually ,these labeled cells were transferred at a sum of 1～1.5X106 cells onto the homologous material of natural bone.Three days later,the composites were transplanted into a 15 mm-length segmental bone defect of rabbit periosteum (trial group).The control group was implanted with the material of natural bone into the defects. The rabbits were observed generally for 6 weeks after operation. Radiographs were made at 3 ,6 weeks postoperatively.At 6 weeks the animals were sacrificed and involved radius were removed. After macroscopic examination ,the defects and adjacent bone were prepared for undercalcified histological sections and immunohistochemical staining of BrdU.Results: BMSCs flourished in DMEM plus 10% fetal bovine serum. The induced cells expressed ALP and type I collagen and calcium nodules were...