Engineered Regeneration of Bone through a Small Molecule Cyclic Adenosine Monopho

描述（由申请人提供）：间充质干细胞刺激成骨细胞分化和矿化是骨再生和修复的潜在新方法。传统上，大分子生长因子如骨形态发生蛋白（BMP）已用于人类和动物的骨再生。不幸的是，这些生物因子的使用具有缺点。蛋白质的不稳定性、成本、免疫原性和超生理剂量是涉及BMP的主要问题。因此，有必要研究能够减少甚至避免这些限制的替代生长因子。在这里，我们提出了一种新的策略，通过成骨细胞分化使用稳定的小分子骨再生。PI的初步数据的小组提出，一种新开发的小分子cAMP类似物，N6-苯甲酰腺苷-3 '，5'-环一磷酸（6-Bnz-cAMP），促进初始细胞粘附并支持生物可降解聚合物聚（乳酸-共-乙醇酸）支架上的增殖。此外，它诱导成骨细胞样MC 3 T3-E1细胞的分化和基质矿化。本研究的目的是：1）评价6-Bnz-cAMP在兔间充质干细胞中的骨诱导潜力，2）直接比较6-Bnz-cAMP和BMP-2的骨诱导作用，3）开发和评价一种新的骨移植材料系统，该系统包括可生物降解的PLAGA微球基质和小分子6-Bnz-cAMP。将使用兔尺骨临界尺寸缺损模型在体内检查新型6-Bnz-cAMP负载的基于微球的支架的生物学性能。我们假设，所提出的微球支架系统的生物活性将通过掺入小分子6-Bnz-cAMP而显著改善。我们进一步假设使用小分子-聚合物基质系统将导致体内骨组织再生。

DESCRIPTION (provided by applicant): Stimulation of osteoblast differentiation and mineralization from mesenchymal stemcells is a potential new approach for bone regeneration and repair. Traditionally, large molecule growth factors such as bone morphogenetic proteins (BMPs) have been used in humans and animals to regenerate bone. Unfortunately, the use of these biological factors has shortcomings. Protein instability, cost, immunogenicity, and supraphysiological dosage are the major concerns involving BMPs. There is thus a need to examine alternative growth factors that can reduce or even avoid these limitations. Here we propose a new strategy for bone regeneration via osteoblast differentiation using a stable small molecule. Preliminary data in the P.I.'s group suggest that a newly developed small molecule cAMP analogue, N6-Benzoyladenosine-3',5'- cyclic monophosphate (6-Bnz-cAMP), promotes initial cell adhesion and supports proliferation on biodegradable polymeric poly(lactic acid-co-glycolic acid) scaffolds. Further, it induces differentiation and matrices mineralization of osteoblast-like MC3T3-E1 cells. The objectives of the present research proposal are 1) to evaluate the osteoinductive potential of 6-Bnz-cAMP in rabbit mesenchymal stem cells, 2) to directly compare the osteoinductive effects of 6-Bnz-cAMP and BMP-2, 3) to develop and evaluate a novel bone grafting material system comprising biodegradable PLAGA microspheres matrices with small molecule 6-Bnz-cAMP. The biological performance of the novel 6-Bnz-cAMP loaded microsphere based scaffold will be examined in vivo using a rabbit ulnar critical size defect model. We hypothesize that the bioactivity of the proposed microspheres scaffold system will be significantly improved by the incorporation of the small molecule 6-Bnz-cAMP. We further hypothesize that the use of the small molecule- polymeric matrix system will result in bone tissue regeneration in vivo.