Muscle Based Tissue Engineering to Improve Bone Healing

描述(申请人提供)：节段性骨缺损和骨不连 在头面部骨骼中相对常见。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、速度快 血流清除限制了这项技术的成功。基因治疗 和组织工程方法，可以实现高水平的表达 这些蛋白质可能有助于进一步改善颅面骨愈合。我们的 最近分离的肌源性干细胞克隆群(mcl3细胞) 可以表达干细胞标记物，分化为肌源性和 成骨血统，更重要的是，改善颅骨的骨愈合 骨缺损可能是介导基因转移的理想细胞群 成骨蛋白。这项拟议项目的长期目标是 基于这一新群体的基因治疗方法的发展 肌肉来源的干细胞可以有效地传递成骨蛋白和 促进颅面骨愈合。这些肌肉来源的机制 骨形态发生蛋白-2影响干细胞向成骨细胞分化 和BMP-4进行检测和比较。此外，我们建议将 基于肌肉的组织工程的指定方法 肌源性干细胞体外基因转移成骨蛋白的实验研究 复合支架促进小鼠颅骨愈合 叛逃。我们将研究成骨蛋白表达的持久性， 免疫反应和不良副作用的存在与 这些蛋白的过度表达及其在骨折中的生物学效应 治愈。使用血管内皮生长因子(VEGF)是一种众所周知的 血管生成因子，对进一步改善骨愈合也有一定的作用。 尽管这项拟议的研究将集中在基于肌肉的组织工程上 为了再生颅骨缺陷，这项技术最终将应用于 其他颅面部位，以及附属骨。拟议的研究 将增强和扩大我们对骨愈合的知识，并发展出一种临床 基于新的分子疗法治疗骨质疏松症 不足之处。

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.