Improving Endoderm Specification with Hybrid Materials and Growth Factors

利用混合材料和生长因子改善内胚层规格

• 批准号: 8063863
• 负责人: Adam J Engler
• 金额: $ 17.15万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2013-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8063863
• 关键词: 3-Dimensional; Address; Adult; Affect; American; Biochemical; Biocompatible Materials; Cells; Chronic; Commit; Complex; Confocal Microscopy; Controlled Environment; Coupled; Cues; Development; Endoderm; Environment; Extracellular Matrix; Feedback; Fibronectins; Functional disorder; Future; Gastrointestinal tract structure; Growth Factor; Hyaluronic Acid; Hybrids; Hydrogels; Implant; Integrins; Intestines; Kidney; Liver; Maps; Mass Spectrum Analysis; Measures; Monitor; Myoblasts; Organ; Organ Donor; Osteoblasts; Pattern; Polymers; Process; Production; Property; Proteins; Relative (related person); Science; Screening procedure; Signal Transduction; Spectrum Analysis; Stem cells; Stimulus; Structure; Sulfhydryl Compounds; Techniques; Therapeutic; Time; Tissue Engineering; Tissues; Variant; base; cell type; cellular engineering; crosslink; design; embryonic stem cell; improved; insight; next generation; novel; poly(ethylene glycol)diacrylate; public health relevance; regenerative therapy; scaffold; spatiotemporal; stem cell biology; stem cell differentiation; stem cell fate; success

DESCRIPTION (provided by applicant): Over the past decade, the unique intersection of the fields of stem cell biology and material science have produced a number of key observations about the interaction between stem cells and their surrounding niche. In addition to well-studied growth factors, specific intrinsic properties of the extracellular matrix appear to be sufficient to initiate stem cell differentiation, e.g. more rigid substrates produce myoblast- and osteoblasts-like cell types. However, these materials typically display only a single intrinsic matrix property or they lack the appropriate fibrillar structure, combination with growth factors, or spatiotemporal variations found in matrix during development. As a result, the utility of engineered tissues using these synthetic materials have been somewhat limited. Given the relative spatial and temporal complexity of definitive endoderm-derived tissues, e.g. digestive tract, liver, etc., a more prudent initial approach may be to better mimic the niche via the intrinsic matrix properties that are most germane to the production of definitive endoderm. Using physiologically-relevant combinations of growth factor signals and matrix properties, embryonic stem cells (ESCs) will be monitored for endoderm specification to determine which set of these cues or "design criteria" is most effective. We will then integrate our understanding of these criteria into two "smart," natural-synthetic hybrid biomaterials: 1) a thiolated hyaluronic acid and fibronectin matrix coupled to time-sensitive crosslinking from poly(ethylene glycol)-diacrylate to yield temporal variations of these intrinsic properties and 2) an interpenetrating polymer- fibronectin network to create spatial gradients and features having specific intrinsic matrix properties. Both materials will create dramatically more complex microenvironments compared to current biomaterials as well as better mimic the endoderm niche, which may improve ESC-to-endoderm differentiation. Novel techniques, such as force mapping spectroscopy, will aid in our characterization of these materials' biophysical and biochemical properties and will feedback into material design to create natural-synthetic hybrid substrates that are best-suited for ESCs. These insights will provide both a first set of clear-cut design criteria for the scaffolds as well as develop a process to create future therapeutic biomaterials. PUBLIC HEALTH RELEVANCE: Over 30 million Americans suffer from some form of chronic dysfunction of a definitive endoderm-derived organ, e.g. digestive tract, kidney, liver, etc., and given a lack of donor organs, the need to develop long-term organ replacement strategies is vital. Engineered tissues have been proposed as a means of dealing with this crisis, where embryonic stem cells would be grown into a tissue and subsequently implanted in the body to alleviate the dysfunction. Previous attempts, however, have had limited success in developing such tissues, likely since they do not address the intrinsic properties of the surrounding environment, which are known to direct stem cells into specific types of adult tissues.

描述（由申请人提供）：在过去的十年中，干细胞生物学和材料科学领域的独特交叉产生了许多关于干细胞与其周围生态位之间相互作用的关键观察结果。除了经过充分研究的生长因子外，细胞外基质的特定内在特性似乎足以启动干细胞分化，例如细胞分化。更坚硬的基质产生成肌细胞和成骨细胞样细胞类型。然而，这些材料通常仅表现出单一的内在基质特性，或者它们缺乏适当的纤维结构、与生长因子的组合或在开发过程中在基质中发现的时空变化。因此，使用这些合成材料的工程组织的效用受到了一定程度的限制。 鉴于定形内胚层衍生组织的相对空间和时间复杂性，例如消化道、肝脏等，更谨慎的初始方法可能是通过与定形内胚层的产生最密切相关的内在基质特性来更好地模拟生态位。使用生长因子信号和基质特性的生理相关组合，将监测胚胎干细胞（ESC）的内胚层规格，以确定哪一组线索或“设计标准”最有效。然后，我们将对这些标准的理解整合到两种“智能”天然合成混合生物材料中：1）硫醇化透明质酸和纤连蛋白基质与聚（乙二醇）二丙烯酸酯的时间敏感交联耦合，以产生这些内在特性的时间变化；2）互穿聚合物-纤连蛋白网络以创建 具有特定内在矩阵属性的空间梯度和特征。与目前的生物材料相比，这两种材料都将创造出更加复杂的微环境，并更好地模拟内胚层生态位，这可能会改善 ESC 向内胚层的分化。力图谱等新技术将有助于我们表征这些材料的生物物理和生化特性，并将反馈到材料设计中，以创建最适合ESC的天然合成混合基材。这些见解将为支架提供第一套明确的设计标准，并开发创建未来治疗性生物材料的工艺。 公共卫生相关性：超过 3000 万美国人患有某种形式的定形内胚层衍生器官的慢性功能障碍，例如：消化道、肾脏、肝脏等，鉴于供体器官的缺乏，制定长期的器官替代策略至关重要。工程组织已被提议作为应对这一危机的一种手段，其中胚胎干细胞将生长成组织，然后植入体内以缓解功能障碍。然而，之前的尝试在开发此类组织方面取得的成功有限，可能是因为它们没有解决周围环境的内在特性，而众所周知，周围环境可以将干细胞引导到特定类型的成体组织中。