Experimental Studies On The Construction And Application In Distraction Osteogenesis Of The Nano Cellular Injectable Tissue-engineered Bone

PART I: The experimental study on the osteoblasts induced from rabbits bone marrow stem cells and renal vascular endothelial cells direct co-culture in vitroObjective To study the influence of biological characteristics and optima ratio of the osteoblasts induced from rabbits BMSCs and renal vascular endothelial cells direct co-culture in vitro.Methods Osteoblasts induced from BMSCs were co-cultured directly with renal vascular endothelial cells in different ratios, osteogenesis were detected by inverted microscope, cell count method, alkaline phosphatase activity assay respectively.Results Osteoblasts can be induced from BMSCs by conditional medium. The proliferation of the two kinds cells are all increased significantly than the single cell was cultured directly. The ALP activity of osteoblast was increased significantly than without culturing with endothelial cells. The proliferation and the ALP activity of the two kinds of cells in a ratio of 2:1 is higher than the others.Conclusions BMSCs can be induced successfully to osteoblasts in vitro. There were good cellular compatibility between the osteoblasts and endothelial cells when the two kinds of cells were co-cultured in vitro, moreover, enhance the proliferation and the function of the osteoblasts. Osteoblasts induced from rabbits BMSCs and renal vascular endothelial cellsdirect co-cultured in a ratio of 2:1 is optimal.PART II: The study on the construction of the nano cellular injectable tissue-engineered bone and its cellular compatibilityObjective To explore the cellular compatibility of the injectable NHAC.Methods To observe the morphologic and function of the co-cultured cells with the injectable NHAC in vitro.Results The co-cultured cells can proliferate and growth normally with the injectable NHAC. The cellular activity and alkaline phosphatase activity were not influenced by the injectable NHAC.Conclusions The injectable NHAC has good biocompatibility and can be used as ideal biomaterial in bone tissue engineering.PART III: Animal model of distraction osteogenesisObjective To establish suitable animal model for distraction osteogenesis.Methods New Zealand rabbits were used in the experiment for distraction osteogenesis. An osteotomy is performed at metaphysis, followed by fixation with an external fixator. After a latency period of 5 days, lengthened at 1 mm/day for 20 days. Regeneration of new bone was studied by grossly examination, histological examination and X-rays examination.Results The model of our experiment was coincided with the animal model of distraction osteogenesis by observation of grossly examination, histological examination and X-rays examination.Conclusions Animal model of distraction osteogenesis was made successfully and can be used in future studies.PART IV: The animal experimental study on the application in distraction osteogenesis of the nano cellular injectable tissue-engineered boneObjective To explore the osteogenesis after the application of the nano cellular injectable tissue-engineered bone.Methods Observed the angiogenesis and osteogenesis by Capillaries count, bone trabecula area percent, histological examination, X-rays examination, bone mineral density examination, biomechanics examination after the application of the nano cellular injectable tissue-engineered bone in D groups. At the same time compared with the empty control group-A groups, co-cultured cells group-B groups, injectable NHAC group-C groups.Results The more angiogenesis and bone trabecula area percent was observed in D groups than the others. And D groups' quality of regeneration of new bone was highest in four groups by X-rays examination, bone mineral density examination and biomechanics examination.Conclusions The nano cellular injectable tissue-engineered bone can accelerate the osteogenesis and bone restoration. The nano cellular injectable tissue-engineered bone excelled co-cultured cells or injectable NHAC in osteogenesis.