• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Engineering spatial patterns of gene expression: Fundamental studies of guided cellular processes and applications to tissue regeneration .
【24h】

Engineering spatial patterns of gene expression: Fundamental studies of guided cellular processes and applications to tissue regeneration .

机译：基因表达的工程空间模式：指导性细胞过程及其在组织再生中的应用的基础研究。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Natural tissues can have complex architectures characterized by the organization of multiple cells into structures, such as branching networks of the vascular or nervous systems. This cellular organization arises, in part, from spatial patterns in the expression of soluble factors, which create concentration gradients that direct cellular processes during morphogenesis. Regenerative strategies for damaged tissue must recreate these cellular architectures to restore function. Biomaterials serve a central role in the engineering of functional tissue replacements, and are designed to present a combination of insoluble and soluble signals that direct tissue formation. Gradients of insoluble signals have been created at biomaterial surfaces; however, generation of gradients of soluble signals has proven more difficult. By combining non-viral gene delivery strategies with soft lithography, I have developed methods to spatially pattern gene expression. Using DNA encoding for soluble growth factors, transfection leads to localized and sustained secretion thereby creating concentration gradients as the factors diffuse. In this thesis, the systems are utilized to investigate fundamental questions in neurite guidance and are applied to the rational design of tissue engineering scaffolds. Spatial patterns of gene expression within a cluster of cells were established and the gradients formed by diffusion were mathematically modeled. Neuronal responses to NGF gradients formed by patterned expression were experimentally determined using an in vitro co-culture model, and the width of the pattern governed neuronal response. Patterns 100-250 mum in width confined neuron survival and neurite extension to the region of localized expression. Patterns of 500-1000 mum in width guided neurite extension up the NGF gradient, with guidance dependent on the amount of NGF on the surface and the distance a neuron was cultured from the pattern. Spatial patterns of gene expression were next established within single cells, by altering the extent of transgene expression and transfection efficiency. The gene expression patterns were combined with topographically patterned scaffolds to determine the design parameters necessary for directed neurite extension during nerve regeneration strategies. Neurite guidance was governed by the topographical pattern width and the extent of transgene expression by transfected cells. Photopolymerizable hydrogels were developed to extend spatially patterned gene expression to three-dimensional systems. Hydrogels were characterized in terms of mechanical properties, DNA vector release, and in vivo cell migration and transfection. These studies demonstrate the capacity of patterned gene expression to create concentration gradients of soluble factors that can locally organize tissue formation. The systems developed in this thesis provide a platform with which to investigate concentration gradients in tissue formation, and may be applied for the engineering of functional tissue replacements.
机译：天然组织可以具有复杂的结构，其特征在于将多个细胞组织成结构，例如血管或神经系统的分支网络。这种细胞组织部分地源于可溶性因子表达的空间模式，该空间模式产生了在形态发生过程中指导细胞过程的浓度梯度。受损组织的再生策略必须重建这些细胞结构以恢复功能。生物材料在功能性组织置换的工程设计中起着核心作用，并被设计为呈现指导组织形成的不溶和可溶信号的组合。在生物材料表面产生了不溶信号的梯度。然而，事实证明，生成可溶信号的梯度更加困难。通过将非病毒基因递送策略与软光刻技术相结合，我已经开发出了空间表达基因表达的方法。使用编码可溶性生长因子的DNA，转染导致局部和持续分泌，从而随着因子扩散而产生浓度梯度。在本文中，该系统用于研究神经突引导中的基本问题，并应用于组织工程支架的合理设计。建立了细胞簇内基因表达的空间模式，并通过数学方法建模了通过扩散形成的梯度。使用体外共培养模型，通过实验确定了通过模式表达形成的对NGF梯度的神经元反应，并且模式的宽度决定了神经元反应。宽度为100-250毫米的模式将神经元生存和神经突延伸限制在局部表达区域。宽度为500-1000微米的引导神经突向NGF梯度延伸的模式，其指导取决于表面上NGF的量以及神经元从模式中培养的距离。接下来，通过改变转基因表达的程度和转染效率，在单个细胞内建立基因表达的空间模式。将基因表达模式与地形图模式的支架相结合，以确定神经再生策略中定向神经突延伸所需的设计参数。神经突的指导受地形图宽度和转染细胞转基因表达程度的控制。开发了可光聚合的水凝胶，以将空间模式化的基因表达扩展到三维系统。根据机械性能，DNA载体释放以及体内细胞迁移和转染来表征水凝胶。这些研究证明了模式化基因表达产生可局部组织组织形成的可溶性因子浓度梯度的能力。本文开发的系统提供了一个平台，可用来研究组织形成中的浓度梯度，并可用于功能性组织置换的工程设计。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号