Bone Tissue Engineerig: Effect of Dynamic Perfusion

骨组织工程：动态灌注的影响

• 批准号: 7471894
• 负责人: Aaron Sanford Goldstein
• 金额: $ 16.54万
• 依托单位: VIRGINIA POLYTECHNIC INST AND ST UNIV
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-01 至 2010-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7471894
• 关键词: Angiogenic Factor; Annual Reports; Area; Autologous; BMP2 gene; Biocompatible Materials; Bioluminescence; Blood Vessels; Bone Morphogenetic Proteins; Bone Regeneration; Bone Substitutes; Bone Tissue; Bone Transplantation; Cell Survival; Cells; Cellular biology; DNA Binding; Defect; Deposition; Devices; Engineering; Family; Gene Expression; Gene Silencing; Gene Targeting; Genes; Goals; Gold; Growth; Healed; Image; In Situ; In Vitro; Infiltration; Innate Bone Remodeling; Luciferases; MAPK14 gene; Manufactured Materials; Measures; Mitogen-Activated Protein Kinases; Modality; Molecular; Molecular Probes; Monitor; Nutrient; Outcome; Oxygen; Patients; Perfusion; Phosphorylation; Procedures; Proteins; Public Health; Pulsatile Flow; RNA Interference; Rate; Repair Material; Reporter; Reporter Genes; Research Personnel; Research Project Grants; Role; Sales; Signal Pathway; Signal Transduction; Site; Small Interfering RNA; Source; Standards of Weights and Measures; Stem cells; Stimulus; System; Technology; Testing; Tissue Engineering; Tissues; Transactivation; Transcription Factor AP-1; Translations; Transplantation; Treatment Protocols; Validation; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors; X-Ray Computed Tomography; bone; bone morphogenetic protein 2; bone morphogenetic protein 7; design; fluid flow; gene induction; healing; implantation; in vivo; innovation; insight; molecular imaging; novel; reconstruction; repaired; response; scaffold; size; stem

DESCRIPTION (provided by applicant): Successful healing of critical-sized bone defects requires the implantation of a bioactive material that is capable of stimulating vascular infiltration, tissue integration, and normal bone remodeling. To date, engineered tissues consisting of progenitor cells cultured within porous scaffolds have not been as effective as pharmacologic agents for the repair of bone defects, and we postulate that this stems from an insufficient deposition of bioactive factors during in vitro culture. We propose that in vitro perfusion culture of osteoprogenitor cells remains a promising means for achieving clinically effective materials, but that culture strategies conducive to the deposition of osteogenic and angiogenic factors must be identified. Recently, we have found that expression of the osteogenic factor bone morphogenetic protein (BMP)-2 and the angiogenic factor vascular endothelial growth factor (VEGF)-A are induced by perfusion, and that BMP-2 expression in particular is sensitive to pulsatile perfusion. This indicates that mechanotransductive signaling regulates induction of this important bioactive factor, and points to a need to understand the underlying signaling mechanisms, which then may be harnessed to produce bioactive materials. Therefore, the goals of this project are 1) to probe the mechanisms by which pulsatile flow induces expression of BMPs and VEGF-A, and 2) to implement a non-destructive imaging modality to monitor expression of BMP-2 in perfused porous scaffolds. We emphasize that this project will focus on the induction of BMP-2, 4, and 7 and VEGF-A by pulsatile flow. The specific aims of this two-year project are: 1) Determine the effect of pulsatile flow regimens on the induction of BMPs and VEGF, and the activation of discrete signaling pathways. 2) Determine the role of molecular signaling through p38 on the induction of BMPs. 3) Implement bioluminescence computed tomography to image BMP-2 expression in perfused scaffolds. This multi-disciplinary research project integrates tissue engineering, molecular cell biology, and imaging both to advance our fundamental understanding of mechanotransductive signaling pathways, and to develop an enabling technology for tissue engineering. These goals are applied to bone tissue engineering, but have broad applicability to all areas of tissue engineering. The innovative components of this project include planar and 3D perfusion devices to activate mechanotransductive signaling, siRNA technology to probe signaling pathways, and bioluminescence computed tomography to monitor gene induction. PUBLIC HEALTH RELEVANCE Autologous bone graft transplanted from one site in the patient to another is the gold standard material for repair of critical-sized defects, but limited tissue availability and concerns of donor-site complications drive a growing demand for bone substitutes for reconstructive procedures. Sales of bone substitutes were estimated to total $900 million worldwide in 2005, with an annual grows rate of 10% [1]. Recently, orthobiologic materials have emerged as a promising alternative to conventional synthetics, and have a projected growth rate of 74% annually. These materials consist of bioactive proteins that stimulate integration, vascular infiltration, and tissue remodeling embedded within conventional biomaterials (e.g., Infuse Bone Graft, OP-1 Putty [2, 3]). We have extensive evidence that a tissue engineering approach involving culturing of osteoprogenitor cells in porous scaffolds under dynamic perfusion can be used to create a bioactive material (containing osteogenic and angiogenic factors) that may be a tractable alternative to current orthobiologics. The goals of this project are to probe the underlying molecular mechanisms by which perfusion regulates the synthesis of this bioactive matrix, and to develop a non-destructive molecular imaging modality to monitor this synthesis. 1. Artimplant. http://www.artimplant.se/investors/annual_reports. 2005. 2. http://www.fda.gov/cdrh/MDA/DOCS/h020008.html. OP-1 Putty - H020008. 2004. 3. http://www.fda.gov/cdrh/mda/docs/p000058.html. InFUSE" Bone Graft/LT-CAGE" Lumbar Tapered Fusion Device - P000058. 2002.

描述（由申请人提供）：成功愈合临界骨缺陷需要植入能够刺激血管浸润，组织整合和正常骨重塑的生物活性材料。迄今为止，由在多孔支架中培养的祖细胞组成的工程组织不如药物修复骨缺损的药理剂那样有效，我们假设这源于体外培养过程中生物活性因子的沉积不足。我们建议，在临床上有效的材料中，在体外灌注培养物仍然是一种有希望的手段，但是必须确定有利于沉积成骨和血管生成因子的培养策略。最近，我们发现成骨因子骨形态发生蛋白（BMP）-2和血管生成因子血管内皮生长因子（VEGF）-a的表达是由灌注诱导的，并且BMP-2的表达尤其对脉冲灌注敏感。这表明机械转移信号传导调节了这种重要的生物活性因子的诱导，并指出需要了解潜在的信号传导机制，然后可以利用这些信号机制来产生生物活性材料。因此，该项目的目标是1）探测脉动流动诱导BMP和VEGF-A表达的机制，以及2）实施非破坏性成像模态以监测BMP-2在灌注多孔脚手架中的表达。我们强调，该项目将集中在脉冲流量的诱导BMP-2、4和7和VEGF-A上。这个为期两年的项目的具体目的是： 1）确定脉冲流方案对BMP和VEGF诱导的影响，以及离散信号通路的激活。 2）确定分子信号通过p38在诱导BMP中的作用。 3）实施生物发光计算机断层扫描以在灌注脚手架中成像BMP-2的表达。 这个多学科研究项目整合了组织工程，分子细胞生物学和成像，以促进我们对机械转移信号通路的基本理解，并为组织工程开发启用技术。这些目标适用于骨组织工程，但对组织工程的所有领域都有广泛的适用性。该项目的创新组件包括平面和3D灌注设备，以激活机械转移信号传导，siRNA技术探测信号传导途径以及生物发光计算机断层扫描以监测基因诱导。 公共卫生相关性自体骨移植物从患者的一个部位移植到另一个部位是修复关键尺寸缺陷的金标准材料，但组织可用性有限，并且对供体现场并发症的担忧促使对重建程序的骨骼替代品的需求不断增长。骨骼替代品的销售额估计为2005年全球9亿美元，年增长率为10％[1]。最近，原生物学材料已成为常规合成材料的有希望的替代品，预计的增长率每年为74％。这些材料由刺激整合，血管浸润和组织重塑的生物活性蛋白组成，这些蛋白质嵌入了常规生物材料中（例如，输注骨移植物，OP-1 Putty [2，3]）。我们有广泛的证据表明，在动态灌注下涉及多孔支架中的骨源细胞培养的组织工程方法可用于创建生物活性材料（含有成骨和血管生成因子），这可能是当前正直生物学的易于替代品。该项目的目标是探测灌注调节该生物活性基质合成的潜在分子机制，并开发出一种非破坏性分子成像方式来监测该合成。 1。载液。 http://www.artimplant.se/investors/annual_reports。 2005。2。http：//www.fda.gov/cdrh/mda/docs/h020008.html。 OP -1 PUTTY -H020008。 2004。3。http：//www.fda.gov/cdrh/mda/docs/p000058.html。注入“骨移植/lt盘”腰部锥形融合装置-P000058。 2002。