CAREER: Engineered Affinity-Based Biomaterials for Harnessing the Stem Cell Secretome

干细胞由于具有修复损伤和病变组织的潜力，在再生医学领域具有巨大的前景。然而，干细胞的前景尚未得到充分实现，因为大多数干细胞在损伤后移植入体内，在移植后迅速死亡。尽管它们的命运如此，这些干细胞仍然经常设法对它们被移植的受损组织产生一些小的积极影响。这种愈合反应部分是由于干细胞分泌的蛋白质进入周围的损伤环境，可以减少炎症，使环境更适合宿主细胞的浸润，使损伤组织再生。然而，蛋白质通常也不会在损伤部位停留很长时间，这使得它们的作用很短暂。这项CAREER提案的目标是开发生物材料来捕获和浓缩这些有效的细胞分泌蛋白，以增强和延长其治疗效果，超出干细胞生存的初始阶段。这些生物材料将被设计成只从细胞分泌蛋白质的复杂混合物中捕获感兴趣的特定蛋白质，从而使它们充当筛子——在不捕获无效蛋白质的情况下富集治疗性蛋白质。从广泛的社会影响来看，从复杂的混合物中选择性地富集再生蛋白的能力可能会改变干细胞移植的治疗潜力，对治疗许多疾病和损伤有影响，包括肌肉骨骼损伤、心血管疾病和脊髓损伤。这个高度跨学科的项目需要对生物工程、化学、生物学和人体生理学感兴趣的学生参与，并将吸引俄勒冈大学多个部门的学生参与生物工程研究和教育。将开发一个包容性的生物工程教育课程，为来自不同学科的学生提供必要的技能，以发展可持续的生物工程外展活动，这些活动反过来可用于促进在科学，技术，工程和数学（STEM）中代表性不足的K-12学生的生物工程途径。通过在多个层次（K-12，本科生和研究生）增加生物工程课程的机会，提议的工作将使有技能和愿望从事跨学科生物工程研究的有才华的科学家和工程师多样化。技术摘要间充质干细胞（mesenchymal stem/stromal cells, MSCs）分泌的蛋白质可以介导对损伤的免疫反应并刺激组织修复。然而，移植的间充质干细胞生存能力差会限制长期的治疗效果。通过干细胞分泌的蛋白质（即“分泌组”）来利用干细胞的再生潜力代表了组织工程领域最近的一个范式转变。生物材料可用于隔离和延长分泌蛋白的呈现，超过细胞存活的初始时期。然而，目前的生物材料在从复杂蛋白质混合物中选择性隔离特定靶蛋白的能力有限。本CAREER提案的目标是开发一个基于亲和力的生物材料库，可以选择性地隔离和呈现由MSCs分泌的治疗性蛋白质。本文将采用几个关键的创新，包括使用定向进化来识别目标蛋白质和材料之间的高特异性亲和相互作用，以及使用生物运输模型来预测蛋白质-材料亲和相互作用和蛋白质分泌率对整体蛋白质封存的影响，从而优化用于蛋白质封存的生物材料。这个高度跨学科的项目需要对生物工程、化学、生物学和人体生理学感兴趣的学员参与，并将吸引俄勒冈大学多个部门的学生参与生物工程研究和教育。将开发一个包容性的生物工程教育课程，以增加获得生物工程课程的机会，并为来自不同学科的学生提供专业和教学技能，以开发可持续的生物工程外展活动，这些活动反过来可用于促进在STEM中代表性不足的K-12学生的生物工程途径。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical AbstractStem cells hold tremendous promise for the field of regenerative medicine due to their potential to repair injured and diseased tissues. However, the promise of stem cells has not been fully realized, as the majority of stem cells transplanted into the body after injury die rapidly after transplantation. Despite their fate, these stem cells still often manage to have a small positive impact on the damaged tissues into which they are transplanted. This healing response is partly due to the proteins secreted by the stem cells into the surrounding injury environment, which can reduce inflammation and make the environment more hospitable for the infiltration of host cells to regenerate the injured tissue. However, proteins typically also do not remain within the injury site for long periods of time, making their effects short-lived. The goal of this CAREER proposal is to develop biomaterials to capture and concentrate these potent cell-secreted proteins to enhance and prolong their therapeutic effects beyond the initial period of stem cell survival. These biomaterials will be engineered to only capture specific proteins of interest from a complex mixture of cell-secreted proteins, thereby allowing them to act as sieves – enriching therapeutic proteins without trapping ineffective proteins. Toward broad societal impact, the ability to selectively enrich regenerative proteins from complex mixtures could transform the therapeutic potential of stem cell transplantation with implications for treating many diseases and injuries, including musculoskeletal injuries, cardiovascular disease, and spinal cord injury. This highly interdisciplinary project requires participation by students interested in bioengineering, chemistry, biology, and human physiology, and will engage students across multiple departments at the University of Oregon in both bioengineering research and education. An inclusive bioengineering education course will be developed to give students from a variety of disciplines the skills necessary to develop sustainable bioengineering outreach activities that can, in turn, be used to promote pathways to bioengineering for K-12 students underrepresented in science, technology, engineering, and math (STEM). By increasing access to bioengineering curriculum at multiple levels (K-12, undergraduate, and graduate students), the proposed work will diversify the pool of talented scientists and engineers with the skills and desire to engage in interdisciplinary bioengineering research.Technical AbstractMesenchymal stem/stromal cells (MSCs) secrete proteins that can mediate the immune response to injury and stimulate tissue repair. However, poor viability of transplanted MSCs can limit long-term therapeutic effects. Harnessing the regenerative potential of stem cells through the proteins they secrete (i.e., the “secretome”) represents a recent paradigm shift in the field of tissue engineering. Biomaterials can be used to sequester and prolong the presentation of secreted proteins beyond the initial period of cell survival. Yet, current biomaterials have a limited ability to selectively sequester specific target proteins from complex protein mixtures. The goal of this CAREER proposal is to develop a library of affinity-based biomaterials that can selectively sequester and present therapeutic proteins secreted by MSCs. Several key innovations will be employed herein, including the use of directed evolution to identify high-specificity affinity interactions between target proteins and materials, and the use of bio-transport modeling to predict the effects of protein-material affinity interactions and protein secretion rates on overall protein sequestration, thereby enabling the optimization of biomaterials for protein sequestration. This highly interdisciplinary project requires participation by trainees interested in bioengineering, chemistry, biology, and human physiology, and will engage students across multiple departments at the University of Oregon in both bioengineering research and education. An inclusive bioengineering education course will be developed to increase access to bioengineering curriculum and give students from a variety of disciplines the professional and pedagogical skills to develop sustainable bioengineering outreach activities that can, in turn, be used to promote pathways to bioengineering for K-12 students underrepresented in STEM.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.