UNS: Collaborative Research: Stem Cell-inspired Nanotherapeutics for Regenerative Repair of Elastic Matrix

PI: Ramamurthi, Anand/ Rao， Raj R提案号：1508642 / 1509377由于成年细胞构建新的弹性纤维的能力很差，因此将结构性受损的柔软弹性组织恢复到健康状态是很困难的，而弹性纤维可以使组织拉伸和后坐力。在这个项目中，研究人员提出了干细胞再生和修复弹性纤维组装和结构的因子的鉴定和表征。此外，研究的目的是使用可降解的聚合物颗粒以持续的方式传递因子，这些颗粒本身经过化学修饰，以刺激新的弹性纤维形成并防止其分解。然后，研究人员将测试这些颗粒治疗腹主动脉瘤的有效性。腹主动脉瘤是一种以主要弹性血管（主动脉）结构破坏为特征的疾病。在未来，该平台技术可以扩展到治疗其他需要结构修复的非血管弹性组织类型（如肺组织）。该提案旨在开发创新的新方法，以实现原位，仿生弹性基质再生修复的柔软，弹性组织结构受损的蛋白水解损伤。提出的方法旨在克服固有的不良的自我再生修复破坏弹性基质稳定的成人细胞类型。研究人员最近发现骨髓间充质干细胞（BM-MSC）衍生的平滑肌细胞（BM-SMCs），而不是未分化的BM-MSCs，比成年血管SMCs（健康的和患病的）具有更强的弹性，它们的分泌物可以刺激患病的、基质组装受损表型的SMCs进行弹性基质再生修复。由于干细胞的物理输送面临着一些挑战，本项目提出设计和测试一种受干细胞启发，但无细胞再生的原位ECM再生修复方法。该方法基于持续的局部递送BM-SMC分泌组成分，这些成分被认为是来自新型聚合物纳米载体的促弹性蛋白再生刺激的必要和充分条件，这些聚合物纳米载体本身具有促弹性和抗蛋白水解特性。通过旨在解决三个特定目标的实验，研究人员将验证以下假设：a)人类BM-MSCs （hBM-MSCs）可以有效地分化为表现出不同的弹性决定表型状态的SMCs (hBM-SMCs)；b) hBM-SMCs对腹主动脉瘤的促弹性作用是由其分泌的营养因子（secretome）介导的；c) hBM-SMC分泌组的关键成分单独或联合对促弹性和抗蛋白水解作用是必要和充分的；d)将关键hBM-SMC分泌组因子的持续递送与纳米载体相结合，将增加再生弹性基质修复在ecm中断的三维组织空间中的数量和质量。这个项目的广泛研究影响是基于它的潜力，一种新的纳米治疗方法可能使再生弹性基质修复，再现SC分泌物的再生作用。通过这个项目，研究人员将a)为不同教育水平的学生开发教育模块，以更好地了解干细胞和组织工程，b)为克利夫兰诊所和弗吉尼亚联邦大学的学生提供独特的机构间合作培训机会。通过在这些机构建立良好的暑期实习和推广项目，研究人员将开发出有利于高中生、本科生和公众的教育模块。本提案由化学、生物工程、环境和运输系统部门的生物医学工程项目和材料研究部门的生物材料项目共同资助。

PI: Ramamurthi, Anand/ Rao, Raj R Proposal Number: 1508642 / 1509377 Restoring structurally damaged soft, elastic tissues to a healthy state is difficult since adult cells are poorly capable of building new elastic fibers, which allow tissues to stretch and recoil. In this project, the investigators propose identification and characterization of factors derived from stem cells towards regenerating and repairing elastic fiber assembly and structure. Further, the studies aim to deliver factors in a sustained manner using degradable polymeric particles which are themselves chemically modified to stimulate new elastic fiber formation and prevent its breakdown. The investigators will then test the effectiveness of the particles in treating abdominal aortic aneurysms, a disorder characterized by breakdown of the structure of the major elastic blood vessel (aorta). In the future, this platform technology can be extended to treat other non-vascular elastic tissue types (e.g., lung tissue) in need of structural repair. This proposal aims to develop innovative, new approaches to enable in situ, biomimetic elastic matrix regenerative repair in soft, elastic tissues structurally compromised by proteolytic injury. The proposed approach seeks to overcome intrinsically-poor auto-regenerative repair of disrupted elastic matrix by stable adult cell types. The investigators have recently shown bone marrow mesenchymal stem cell (BM-MSC)-derived smooth muscle cells (BM-SMCs), but not undifferentiated BM-MSCs, to be significantly more elastogenic than adult vascular SMCs (healthy, diseased), and their secretions to stimulate elastic matrix regenerative repair by SMCs of a diseased, matrix assembly-impaired phenotype. As physical delivery of stem cells faces several challenges, this project proposes to design and test a stem cell-inspired, but cell-free regenerative approach to in situ ECM regenerative repair. The approach is based on sustained, local delivery of BM-SMC secretome components identified to be necessary and sufficient for pro-elastin regenerative stimulus from novel polymer nanocarriers that themselves exhibit pro-elastogenic and anti-proteolytic properties. Through experiments designed to address three specific aims, the investigators will test hypotheses that a) human BM-MSCs (hBM-MSCs) can be efficiently differentiated into SMCs (hBM-SMCs) exhibiting distinct, elastogenicity-determining phenotypic states; b) pro-elastogenic effects of hBM-SMCs on abdominal aortic aneurysm SMCs are mediated by their secreted trophic factors (secretome); c) key components of hBM-SMC secretome individually or in combination are necessary and sufficient for pro-elastogenic and anti-proteolytic effect; and d) integrating sustained delivery of key hBM-SMC secretome factor(s) with nanocarriers will augment quantity & quality of regenerative elastic matrix repair in an ECM-disrupted, 3-D tissue space. The broad research impact of this project is based on its potential that a novel nanotherapeutic approach may enable regenerative elastic matrix repair that recapitulates regenerative effects of SC secretions. Through this project, the investigators will a) develop educational modules for students at several educational levels to better understand stem cell- and tissue engineering, and b) provide unique inter-institutional collaborative training opportunities for students at Cleveland Clinic and Virginia Commonwealth University. By working through well-established summer internship and outreach programs at these institutions, the investigators will develop educational modules that will benefit high school students, undergraduate students and the general public. This proposal is co-funded by the Biomedical Engineering Program in the Chemical, Bioengineering, Environmental and Transport Systems Division, and by the Biomaterials Program in the Division of Materials Research.