Muscle Based Tissue Engineering to Improve Bone Healing

描述（由申请人提供）：节段性骨缺损和骨不连是 在颅面骨骼中相对常见。成骨蛋白，包括 骨形态发生蛋白2和4（BMP-2，4），可促进骨愈合， 节段性骨缺损，但成骨蛋白的半衰期短， 血液的清除限制了该技术的成功。基因治疗 和组织工程方法，可以实现高表达水平的 这些蛋白质可能有助于进一步改善颅面骨愈合。我们 最近分离的肌源性干细胞（mcl 3细胞）克隆群 它可以表达干细胞标记，分化成肌源性和 成骨谱系，更重要的是，改善颅骨中的骨愈合 骨缺损可能是一个理想的细胞群介导的基因转移， 成骨蛋白本项目的长期目标是： 基因治疗方法的发展基于这种新的人口， 肌肉来源的干细胞，以有效地递送成骨蛋白， 促进颅面骨愈合。这些肌肉衍生的 在BMP-2的影响下，干细胞分化为成骨谱系 和BMP-4将进行测试和比较。此外，我们建议将 肌肉组织工程的指定方法， 肌肉源性干细胞在成骨蛋白离体基因转移中的作用 与支架组合以改善小鼠颅骨中的骨愈合 缺损我们将研究成骨蛋白表达的持续性， 免疫应答的存在和与免疫相关的不良副作用 这些蛋白质的过度表达，以及对骨折的生物学效应， 治愈血管内皮生长因子（VEGF）是一种众所周知的 血管生成因子，以进一步改善骨愈合也将被表征。 虽然这项拟议中的研究将集中在基于肌肉的组织工程 为了再生颅骨缺损，这项技术最终将被应用于 其他颅面部位以及肩胛骨拟议研究 将提高和扩大我们的知识骨愈合和发展临床 基于新分子疗法的相关治疗， 缺陷

DESCRIPTION (provided by applicant): Segmental bone defects and nonunions are relatively common in the craniofacial skeleton. Osteogenic proteins, including bone morphogenetic protein-2 and 4 (BMP-2,4), can promote bone healing in segmental bone defects, but the osteogenic proteins' short half-lives and rapid clearance by the bloodstream limit the success of this technology. Gene therapy and tissue engineering approaches that can achieve high expression levels of these proteins may help to further improve craniofacial bone healing. Our recently isolated clonal population of muscle-derived stem cells (mcl3 cells) that can express stem cell markers, differentiate into both myogenic and osteogenic lineages, and, more importantly, improve bone healing in a calvarial bone defect may be an ideal cell population to mediate gene transfer of osteogenic proteins. The long-term goal of this proposed project is the development of gene therapy approaches based on this novel population of muscle-derived stem cells to efficiently deliver the osteogenic proteins and improve craniofacial bone healing. The mechanism by which these muscle-derived stem cells differentiate into osteogenic lineages under the influence of BMP-2 and BMP-4 will be tested and compared. In addition, we propose to characterize designated approaches of muscle-based tissue engineering using the muscle-derived stem cells in an ex vivo gene transfer of osteogenic proteins in combination with a scaffold to improve bone healing in a mouse calvarial defect. We will investigate the persistence of osteogenic protein expression, the presence of immune response and undesirable side effects related to the overexpression of these proteins, and the biological effects on fracture healing. The use of vascular endothelial growth factor (VEGF), a well-known angiogenic factor, to further improve bone healing will be also characterized. Although this proposed research will focus on muscle-based tissue engineering to regenerate a calvarial defect, this technology ultimately will be applied to other craniofacial sites, as well as appendicular bones. The proposed research will enhance and expand our knowledge of bone healing and develop a clinically relevant treatment based on new molecular therapeutics to treat osseous deficiencies.