Injectable, High Porosity Bone Scaffolds by Emulsion Templating

描述（由申请人提供）：控制细胞过程、生物降解和生物材料支架的机械性能对组织工程设备的发展至关重要。人们普遍认为，特别是支架结构，可以深刻地影响构建的成功。骨组织工程策略的进步很大程度上依赖于高孔隙率支架的发展，这些支架可以承受严格的体内载荷。提出的研究利用乳液模板来产生新的微细胞聚合物作为可注射的，可生物降解的骨再生支架。乳液模板是制备高孔支架的一种较新的方法，涉及高内相乳液（HIPEs）的模板聚合。乳液模板对支架结构的控制使聚乙烯材料成为组织工程支架的有吸引力的候选材料。此外，HIPEs可以在没有溶剂的情况下制成，具有乳液粘度，允许注射，并在体温或体温附近固化。我们建议调整乳液组装过程，以产生具有改进的机械性能和目标降解轮廓的polyHIPE结构。我们假设这些支架的高孔隙度和互联性将通过促进细胞生长、营养物质的流入和废物在整个支架中的运输来增强组织再生。具体目标是：1)开发和表征具有相互关联孔隙度的可注射polyHIPE支架库。2)评价Aim 1中开发的polyHIPE支架作为骨导电性组织工程支架。这些目标的成功完成将产生既可生物降解又可注射的高孔隙度支架。高度多孔支架可注射并在原位固化到合适的机械强度，这是骨科组织工程的重大进步。这种创新的制造设计还提供了对结构的卓越控制，可用于探索组织再生中的关键关系。虽然这些研究主要集中在骨修复上，但乳液模板可以用于产生各种各样的功能移植物。

DESCRIPTION (provided by applicant): Control of cellular processes, biodegradation and mechanical properties of biomaterial scaffolds is critical in the development of tissue engineering devices. It is widely recognized that scaffold architecture, in particular, can profoundly influence the success of the construct. The advancement of bone tissue engineering strategies is strongly dependent on the development of high-porosity scaffolds that can withstand rigorous in vivo loading. The proposed research utilizes emulsion templating to generate novel microcellular polymers as injectable, biodegradable scaffolds for bone regeneration. Emulsion templating is a relatively new method for the production of highly porous scaffolds and involves the template polymerization of high internal phase emulsions (HIPEs). The control of scaffold architecture afforded by emulsion templating makes polyHIPE materials attractive candidates for tissue engineering scaffolds. In addition, HIPEs can be made without solvent, have an emulsion viscosity that permits injectability, and cure at or around body temperature. We propose to tune the emulsion assembly processes to generate polyHIPE architectures with improved mechanical properties and target degradation profiles. We hypothesize that the high porosity and interconnectivity of these scaffolds will augment tissue regeneration by facilitating cellular in-growth, the influx of nutrients and the transport of waste throughout the scaffold. The Specific Aims are: 1) Develop and characterize a library of injectable polyHIPE scaffolds with interconnected porosity. 2) Evaluate polyHIPE scaffolds developed in Aim 1 as osteoconductive tissue engineering scaffolds. Successful completion of these Aims will generate high porosity scaffolds that are both biodegradable and injectable. A highly porous scaffold that is injectable and cures in situ to suitable mechanical strength represents a significant advancement in orthopaedic tissue engineering. This innovative fabrication design also provides exceptional control over the architecture which can be utilized to probe key relationships in tissue regeneration. Although these studies are focused on bone repair, emulsion templating can be utilized to generate a wide variety of functional grafts. PUBLIC HEALTH RELEVANCE: Nationwide Inpatient Statistics show that over 1.1 million surgical procedures involving the partial excision of bone, bone grafting, and inpatient fracture repair were performed in 2004 alone, with an estimated total cost of over $5 billion. Engineered tissue grafts have the potential to repair damaged tissues when traditional transplants are unavailable or fail. The proposed research utilizes emulsion templating to generate injectable, biodegradable scaffolds for the repair of bone defects.