Project 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.
