Enhanced Calvarial Regeneration Via RNAi-Mediated Suppression of BMP Antagonism

描述（由申请人提供）：成功的颅骨缺损再骨化通常局限于未成熟的动物和小于1-2岁的儿童。相反，骨骼成熟的动物表现出一种几乎普遍的无法治愈的能力，即使是很小的环甲缺损，骨骼缺损也会伴随其一生。虽然在过去的一个世纪里已经开发了大量的策略来治疗成人颅骨缺陷，但目前可用的无数方法反映了每种治疗技术的不足之处。然而，通过结合发育生物学、器官发生学、干细胞生物学、生物工程和材料科学的进展，一种新的颅骨组织工程范式已经出现——再生医学。在组织工程和再生医学的众多应用中，考虑到在不久的将来实施转化疗法的诱人潜力，颅骨缺陷代表了最有可能取得临床成功的目标之一。本研究旨在利用人脂肪源性基质细胞（ASCs）确定颅骨再生策略的最佳设计。在Specific Aim 1中，我们将使用rnai介导的BMP拮抗抑制来增强体外成骨。在特异性目标2中，我们将在我们的临界尺寸颅骨缺损裸鼠模型中检测这些细胞在体内再生骨的能力。我们将使用可生物降解的磷灰石涂层聚乳酸-羟基乙酸（PLGA）支架来递送细胞，并确定是否可以通过Noggin的RNA干扰调节BMP信号来增强骨骼愈合。我们还将能够检查移植供体和周围宿主细胞对再生细胞的各自贡献。最终，该应用的转化目标是确定一种基于细胞的再生医学策略，利用组织工程骨修复颅骨缺损。项目描述：成年动物表现出一种几乎普遍的无法治愈的能力，即使是很小的头骨缺陷，骨骼缺损也会伴随其一生。虽然在过去的一个世纪中已经开发了许多治疗成人颅骨缺损的策略，但目前可用的无数方法反映了每种治疗技术的不足之处。然而，通过结合发育生物学、器官发生、干细胞生物学、生物工程和材料科学的进展，骨组织工程的新范式已经出现——再生医学。在组织工程和再生医学的众多应用中，考虑到在不久的将来实施转化疗法的诱人潜力，成人颅骨缺损是最有可能取得临床成功的目标之一。本研究旨在阐明利用人类脂肪细胞的颅骨再生策略。

DESCRIPTION (provided by applicant): Successful re-ossification of calvarial defects is characteristically limited to immature animals and children less than 1-2 years of age. Conversely, skeletally mature animals demonstrate an almost universal inability to heal even small trephine defects, with bone deficits remaining present for the life of the subject. While a plethora of strategies have been developed over the past century for treating adult calvarial defects, the myriad of methods currently available reflects the inadequacies of each therapeutic technique. By combining advances in developmental biology, organogenesis, stem cell biology, bioengineering, and material sciences, however, a new paradigm for calvarial bone tissue engineering has emerged- regenerative medicine. Of the multitude of applications for tissue engineering and regenerative medicine, calvarial defects represent one of the most likely targets to meet with clinical success, given the alluring potential for implementation of translational therapies in the near future. This proposal seeks to determine the optimal design of a calvarial regenerative strategy utilizing human adipose-derived stromal cells (ASCs). In Specific Aim 1, we will use RNAi-mediated suppression of BMP antagonism to enhance in vitro osteogenesis. In Specific Aim 2, we will assay the ability of these cells to regenerate bone in vivo in our critical- sized calvarial defect nude mouse model. We will employ the use of biodegradable apatite-coated poly(DL-lactic-co-glycolic acid) (PLGA) scaffolds to deliver the cells and determine if skeletal healing can be augmented by modulating BMP signaling via RNA interference of Noggin. We will also be able to examine the respective contributions of the implanted donor and surrounding host cells to the regenerate. Ultimately, the translational goal of this application is to determine a cell-based regenerative medicine strategy to repair calvarial defects using tissue engineered bone. Project Narrative: Adult animals demonstrate an almost universal inability to heal even small skull defects, with bone deficits remaining present for the life of the subject. While many strategies have been developed over the past century for treating adult skull defects, the myriad of methods currently available reflects the inadequacy of each therapeutic technique. By combining advances in developmental biology, organogenesis, stem cell biology, bioengineering, and material sciences, however, a new paradigm for bone tissue engineering has emerged- regenerative medicine. Of the multitude of applications for tissue engineering and regenerative medicine, adult skull defects represent one of the most likely targets to meet with clinical success, given the alluring potential for implementation of translational therapies in the near future. This proposal seeks to elucidate a skull regenerative strategy utilizing human fat cells.