Bone Scaffolds for Heat Shock Protein Induced Regeneration and Healing

Pi：Rylander，Nicole Proposal编号：1067654项目摘要：与癌症、损伤、发育异常和退行性疾病相关的骨骼疾病极大地降低了数百万人的健康和生活质量。这些疾病可通过丧失骨骼或其功能而导致严重残疾，从而需要骨替换(每年进行300多万次矫形手术)或有效的再生策略。使用热应力和张应力的调节可以上调ECM的产生、细胞增殖和称为热休克蛋白(HSPs)的分子伴侣。研究表明，上调的热休克蛋白与细胞外基质形成所需的细胞增殖和胶原生物合成增强之间存在联系。最终目标是通过应力调节和热休克蛋白的传递，开发出一种具有变革性的、优越的骨支架，具有促进体内伤口愈合和骨再生的能力。理想的应激调节策略和外源性HSP传递方案将被确定以创造更多的功能骨支架，这些支架促进啮齿动物颅面缺损模型愈合的有效性将被测试。研究的目标是：1)构建一种新型的微生物反应器系统，以施加组合(热+拉伸)应力并创建能够外源性HSP输送和创面愈合的支架；2)利用该微生物反应器系统对骨支架单独施加热应力和拉伸应力，并联合应用HSP输送，以确定促进骨形成的理想条件；以及3)评价经热+拉伸应力和HSP输送预处理的骨支架修复大鼠颅面骨缺损的效果。智力价值：这将是第一个集中于利用基于热休克蛋白的骨再生的潜力的研究，通过组合应力调节和外源性热休克蛋白传递来开发功能性骨支架。另一个新的方面将是结合使用热应力和张应力来促进骨支架内的细胞增殖和骨ECM的形成，并在活体颅面骨缺损模型中进行。将创建并利用第一个此类微生物反应器系统来结合施加热应力和拉应力，以确定促进骨形成的最佳应力调节方案。我们试图创造一种具有变革性的骨支架，这是因为使用了新的制造方法，包括共电纺聚合体和集成的HSP释放微球，通过热+拉应力进行调节，以及将微球表面包裹以将HSP从支架释放到周围组织。能够控制热休克蛋白在支架内和周围伤口部位的时空传递的支架将提供一种独特的途径来促进骨愈合，并促进支架在有损伤或病变组织的患者的现有骨中成功整合。更广泛的影响：这项研究将建立一种促进骨生长和再生的新方法，以开发更可行的骨替代材料和刺激患者骨再生的策略。从这项研究中获得的知识将直接转化为恢复骨组织的功能和消除与骨相关损伤相关的现有残疾。最终，应激调节策略和热休克蛋白传递方法可用于开发广泛的工程化组织替代材料，如韧带、肌腱、肌肉和神经，以允许刺激患者任何类型的受伤或患病组织的愈合。这项研究将使学生在研究生、本科生和高中阶段获得组织工程、生物运输、成像和细胞生物学方面的经验。两名代表性不足的研究生将得到资助。少数民族本科生将融入研究的各个方面，以促进建立一种机制，让学生认识到他们的教育与研究的相关性，从而激励他们在学习中脱颖而出，促进研究生的追求。残疾高中生将体验与该项目相关的第一手研究技术，如支架和微球的制造、使用Instron测试材料特性、调节支架和测量支架响应。这个机会将使学生对生物医学工程产生兴趣，并鼓励学生们相信，尽管他们面临挑战，但研究的未来是可以实现的。

PI: Rylander, NicoleProposal Number: 1067654Project Summary: Bone related disorders associated with cancer, injury, abnormal development, and degenerative conditions dramatically diminish the health and quality of life of millions of people. These disorders can cause significant disability through loss of bone or its functionality, creating a need for bone replacements (over 3 million orthopaedic procedures performed annually) or effective regenerative strategies. Conditioning using thermal and tensile stress can up-regulate ECM production, cell proliferation, and molecular chaperones called heat shock proteins (HSPs). A link has been shown between up-regulated HSPs and enhanced cell proliferation and collagen biosynthesis needed for ECM formation. The ultimate goal is to develop a transformative, superior bone scaffold through stress conditioning and HSP delivery with the capability to enhance wound healing and bone regeneration in vivo. Ideal stress conditioning strategies and exogenous HSP delivery protocols will be identified to create more functional bone scaffolds and the efficacy of these scaffolds to promote healing in a rodent craniofacial defect model will be tested. Study objectives are to 1) Construct a novel microbioreactor system to apply combinatorial (thermal+tensile) stress and create a scaffold capable of exogenous HSP delivery and wound healing, 2) Apply combinatorial thermal and tensile stress alone and in combination with HSP delivery to bone scaffolds using the microbioreactor system and determine ideal conditions for enhancing bone formation, and 3) Evaluate effectiveness of bone scaffolds preconditioned with thermal+tensile stress and HSP delivery to heal bone defects in a rat craniofacial defect model. Intellectual Merit: This will be the first study focused on harnessing the potential of HSP based bone regeneration through combinatorial stress conditioning and exogenous HSP delivery in development of functional bone scaffolds. Another novel aspect will be the combined use of thermal and tensile stress to enhance cell proliferation and bone ECM formation within bone scaffolds and in an in vivo craniofacial bone defect model. A first-of-its-kind microbioreactor system will be created and utilized to apply thermal and tensile stress in combination to allow determination of optimal stress conditioning protocols to promote bone formation. We seek to create a superior bone scaffold which is transformative due to the use of novel fabrication methods comprised of co-electrospinning polymers coupled with integrated HSP releasing microspheres, conditioning with thermal+tensile stress, and surface encapsulation of microspheres for HSP release from the scaffold to the surrounding tissue. Scaffolds capable of controlled HSP delivery spatially and temporally within the scaffold and to the surrounding wound site will provide a unique avenue to stimulate bone healing and promote successful integration of the scaffold within existing bone in patients with injured or diseased tissue. Broader Impacts: This research will establish a new methodology for enhancing bone growth and regeneration for development of more viable bone replacements and strategies for stimulating bone regeneration in patients. Knowledge gained from this study will directly translate to restoring functionality of bone tissue and eliminating the existing disabilities associated with bone-related impairments. Ultimately, stress conditioning strategies and HSP delivery methods can be utilized for development of a wide array of engineered tissue replacements such as ligaments, tendons, muscles, and nerves to permit stimulation of healing of any type of injured or diseased tissue in patients. This research will enable students to gain experience in tissue engineering, biotransport, imaging, and cell biology at the graduate, undergraduate, and high school level. Two underrepresented graduate students will be supported. Minority undergraduate students will be integrated into every aspect of the research to facilitate a mechanism for students to perceive the relevance of their education to research thereby inspiring them to excel in their studies and promote pursuance of graduate school. High school students with disabilities will experience first-hand research techniques related to this project such as fabrication of scaffolds and microspheres, testing of material properties using the Instron, conditioning scaffolds, and measuring scaffold response. This opportunity will create fascination with biomedical engineering and encourage students that despite their challenges a future in research is attainable.