Interactions of ES Cells with 3D Biomaterials

描述（由申请人提供）：随着基于干细胞的组织工程概念的出现，以及可移植祖细胞在治疗各种复杂疾病方面的前景越来越大，涉及胚胎干细胞（ES）高效和受控分化的研究变得越来越重要。基于胚胎干细胞的治疗方法的最终临床适用性依赖于对这些细胞在各种培养环境下的基本生物学的基本理解。我们的初步结果表明，生物材料和动态培养条件对胚胎干细胞的生长和分化有显著影响，特别是对造血谱系。在这里，我们提出了一个详细和系统的研究如何基本的物理和化学性质的三维微环境和不同的培养条件改变胚胎干细胞分化和影响造血。我们的方法是了解静态和动态条件下3D生物材料支架中ES细胞的行为和造血分化。我们假设3D支架和基于生物反应器的培养将提供更多的细胞-细胞和细胞-基质相互作用，允许更好的细胞外基质（ECM）的产生，并为HPCs的产生提供更天然的环境，允许最佳的生长和增殖以及高效分化为功能性树突状细胞。我们进一步假设，生物材料特性（物理和化学）、支架结构、培养条件以及基质细胞的存在，即干细胞的直接微环境，将对分化的胚胎干细胞的分化和基因表达谱产生深远的影响。因此，我们建议在不同的培养条件下使用通路特异性功能基因组研究来了解参与ES细胞分化的信号转导机制。本研究的结果不仅有助于我们进一步了解干细胞分化的基本生物学，而且还使我们能够开发出高效生产功能性组织特异性细胞的新技术，用于按需细胞移植治疗。

DESCRIPTION (provided by applicant): With the emergence of stem cell based tissue engineering concepts, and increasing promise of transplantable progenitor cells in treating a variety of complex disorders, studies involving highly efficient and controlled differentiation of embryonic stem (ES) cells are becoming increasingly relevant. The ultimate clinical applicability of ES cell based therapeutics relies on the fundamental understanding of the basic biology of these cells under various culture environments. Our preliminary results indicate that biomaterials and dynamic culture conditions have significant effects on the growth and differentiation of embryonic stem cells specifically to the hematopoietic lineage. Here we propose a detailed and systematic investigation on how basic physical and chemical properties of the three-dimensional microenvironment and various culture conditions alter ES cell differentiation and influence hematopoiesis. Our approach is to understand ES cell behavior and hematopoietic differentiation in 3D biomaterial scaffolds under both static and dynamic conditions. We hypothesize that 3D scaffolds and bioreactor-based cultures would provide increased cell-cell and cell-matrix interactions, allow better extracellular matrix (ECM) production and provide a more native environment for generation of HPCs, allowing optimal growth and proliferation and efficient differentiation into functional dendritic cells. We further hypothesize that biomaterial properties (physical and chemical), scaffold architecture, culture conditions as well as stromal cell presence i.e. the immediate microenvironment of stem cells, will have profound effects on the differentiation and gene expression profile of differentiating ES cells. Therefore we propose to use pathway-specific functional genomic studies under varying culture conditions to understand the signal transduction mechanisms involved in ES cell differentiation. The results obtained herein will not only help us further understand the basic biology of stem cell differentiation, but also allow us to develop novel techniques for highly efficient production of functional, tissue-specific cells for on-demand cell-transplantation therapies.