Cell Derived Extracellular Matrix BIofiber Engineering

摘要：纤维是一种高度通用的几何形状，可以使用纺织工业开发和常规使用的制造方法制造成一系列植入几何形状（网格、管状、绳状）。不幸的是，合成纤维被人体识别为外来物质，这使得它们难以用作医疗植入物。作为合成纤维的替代品，该项目的总体研究目标是开发一种利用活细胞分泌的胶原蛋白等分子构建的纤维。这些全天然生物纤维将避免人体对合成聚合物材料的外来物质反应，但仍然可以与目前可用的纺织制造技术一起使用，以制造各种医疗产品。更广泛地说，拟议的研究可以帮助建立材料供应，帮助缓解捐赠人体组织的短缺，并解决与使用合成纤维的医疗植入物相关的并发症。为了制造这些生物纤维，研究人员将开发创新的方法来培育细胞群体在实验室生长过程中分泌的分子。具体来说，研究人员将使用关键的人类细胞创建一个细胞衍生生物纤维工具箱，然后探索将这些人类细胞衍生生物纤维制造成有益的医疗植入物的方法。为了增强本研究的广泛影响，本研究将在本科和K-12学术水平的教育项目中得到补充。重点包括创建农村生物医学工程中学暑期课程，将纤维项目纳入大学课程，以及通过参与现有的大学课程让本科生参与进来。技术摘要：研究人员将开发由细胞分泌的细胞外基质（ECM）分子构建的生物材料纤维。为此，研究小组将探索培养细胞群在培养过程中分泌的ECM的方法。虽然从细胞中收集分离分子的方法已经存在了一段时间，但大规模收集细胞分泌的ECM蛋白来制造散装生物材料是独一无二的。总体目标是使用ECM作为合成聚合物纤维的替代品来制造编织生物医学植入物。为了收集细胞分泌的ECM，研究人员将使用溶剂可降解的中空纤维膜（HFM）。当细胞被植入HFM并在培养中生长时，它们分泌大量的ECM分子，这些分子在管腔内积累。创新的一步是，HFM可以使用水混溶溶剂彻底溶解，剥离合成成分，留下积累的ECM纤维。结果是完全由细胞分泌的ECM形成的生物纤维。拟议的研究计划将研究使用临床相关细胞类型（心脏、肌肉、血管）合成下一代人类ECM生物纤维；优化合成方法，模拟前胶原合成方案对ECM生物纤维性能的影响，确定最佳产率和力学性能的组合；基因工程生产细胞具有专门的ECM生产能力，并检查使用它们合成的ECM生物纤维的特性；表征体内宿主对植入ECM生物纤维的反应，特别注意炎症和纤维化组织的形成；最后，创建规模化的生物纤维制造方案，并利用纺织品生产方案来创建编织生物纤维结构。为了增强本研究的广泛影响，该研究将在阿肯色大学内部和作为教育推广的本科和K-12学术水平的综合教育项目中得到补充。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 Abstract:Fibers are a highly versatile geometry that can be fabricated into a range of implant geometries (meshes, tubes, ropes) using manufacturing methods developed and routinely used by the textile industry. Unfortunately, synthetic fibers are recognized by the human body as a foreign material which makes them challenging to use as medical implants. As an alternative to synthetic fibers, the overall research goal of this project is to develop a fiber built using the molecules, like collagen, that are secreted by living cells. These all-natural biofibers would avoid the foreign material response directed by the body against synthetic polymeric materials, but could still be used with currently available textile fabrication techniques in order to make various medical products. More broadly, the proposed research could help establish a supply of materials that would help alleviate the shortage of donated human tissues and address the complications associated with medical implants that use synthetic fibers. To create these biofibers, the investigators will develop innovative methods to farm the molecules that are secreted by populations of cells during growth in the lab. Specifically, the investigators will create a toolbox of cell derived biofibers using key human cells and then explore methods to fabricate these human cell derived biofibers into beneficial medical implants. To enhance the broader impact of this study the research will be complemented by educational projects at the undergraduate and K-12 academic levels. Highlights include the creation of a rural biomedical engineering middle school summer program, the integration of fiber projects into the university courses, and the involvement of undergraduate students through participation in existing University programs.Technical Abstract: The investigators will develop biomaterial fibers that are built from the extracellular matrix (ECM) molecules secreted by cells. To do so the team will explore methods to farm the ECM that is secreted by populations of cells during growth in culture. While methods to collect isolated molecules from cells have existed for some time, the wholesale collection of cell secreted ECM proteins to create bulk biomaterials is unique. The overall goal is to fabricate woven biomedical implants using ECM as an alternative to synthetic polymer fibers. To collect the ECM that cells secrete, the investigators will utilize a solvent degradable hollow fiber membrane (HFM). When cells are seeded into the HFM and grown in culture they secrete a multitude of ECM molecules that accumulate within the lumen. The innovative step is that the HFM can be thoroughly dissolved using a water miscible solvent, stripping away the synthetic component, and leaving behind the accumulated ECM fiber. The result is a biofiber formed entirely from the ECM secreted by cells. The proposed research program will investigate the synthesis of next generation human ECM biofibers using clinically relevant cell types (cardiac, muscle, vascular); optimize synthesis methods and model the influence of pro-collagen synthesis schemes on ECM biofiber properties and identify combinations that optimize yield and mechanics; genetically engineer producer cells with specialized ECM production capabilities and examine the properties of ECM biofibers synthesized using them; characterize the in-vivo host response to implanted ECM biofibers, with particular attention given to inflammation and fibrotic tissue formation; and lastly create scaled-up biofiber manufacturing schemes and utilize textile production schemes to create woven biofiber constructs. To enhance the broader impact of this study the research will be complemented by integrated educational projects at the undergraduate and K-12 academic levels, both within the University of Arkansas and as educational outreach.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.