• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Tissue-engineered mitral valve chordae using directed collagen gel shrinkage.
【24h】

Tissue-engineered mitral valve chordae using directed collagen gel shrinkage.

机译：组织工程化的二尖瓣腱索，使用定向胶原蛋白凝胶收缩。

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

The increase in mitral valve repair has stimulated an interest in developing alternative materials for artificial chordae. We have turned to collagen-based tissue engineering technologies. The principle of directed collagen gel shrinkage involves combining cells and reconstituted type I collagen. However, inappropriate mechanical properties have been one of the main limitations of most collagen-based tissue equivalents.;To improve the strength of chordae equivalents, the parameters that regulate gel contraction and collagen synthesis need to be better understood. I have demonstrated that mechanical properties of the constructs were improved by optimizing cell seeding density, initial collagen concentration, cell passage, serum concentration and culture time. Since the microstructure of tissue components determines their mechanical behavior, I also thoroughly characterized the collagen constructs. The collagen constructs contained a dense collagen core and an outer elastin sheath similar to native chordae, even though only collagen was in the original mixture. I have demonstrated that cells migrated to the surface, where there is less tension, proliferated to multiple layers, and remained in the synthetic phenotype. These cells therefore continued to synthesize elastin, until a continuous sheath eventually developed.;I designed a motorized dynamic loading system to stretch the constructs during culture to improve the mechanical properties further. Data analysis showed that dynamically cultured constructs have better mechanical properties than statically cultured constructs after 8 weeks of culture (P 0.05). Cyclic strain increased their failure strength (from 1.2 to 3.2 MPa), modulus (from 6.5 to 18 MPa), and cell number (by 155%). However, the modulus and failure stress are still at least an order of magnitude less than those of normal human chordae (from adult). Transmission electron microscopy revealed an elastin sheath around the collagen core and the presence of proteoglycan filaments associated with collagen fibrils. In dynamically loaded constructs, collagen fibrils were longer and more aligned and compacted. Dynamic strain produced replacement tissue-engineered materials with good mechanical properties and ultrastructure.;This project has demonstrated that directed collagen gel shrinkage can be used to fabricate mitral valve chordae in vitro.
机译：二尖瓣修复的增加激发了对开发用于人工腱索的替代材料的兴趣。我们已经转向基于胶原的组织工程技术。定向胶原蛋白凝胶收缩的原理包括将细胞与重构的I型胶原蛋白结合。但是，不适当的机械性能一直是大多数胶原基组织等效物的主要局限性之一。为了提高腱索等效物的强度，需要更好地理解调节凝胶收缩和胶原蛋白合成的参数。我已经证明，通过优化细胞接种密度，初始胶原蛋白浓度，细胞传代，血清浓度和培养时间可以改善构建体的机械性能。由于组织成分的微观结构决定了它们的机械行为，因此我也对胶原蛋白结构进行了彻底的表征。即使原始混合物中只有胶原蛋白，胶原蛋白构建物也包含密集的胶原蛋白核心和类似于天然腱索的外部弹性蛋白鞘。我已经证明细胞迁移到表面张力较小的表面，增殖为多层并保留在合成表型中。因此，这些细胞继续合成弹性蛋白，直到最终形成连续的鞘。我设计了一个电动动态加载系统，以在培养过程中拉伸构建体以进一步改善机械性能。数据分析表明，培养8周后，动态培养的结构物比静态培养的结构物具有更好的机械性能（P <0.05）。循环应变增加了它们的破坏强度（从1.2到3.2 MPa），模量（从6.5到18 MPa）和单元数（增加了155％）。但是，模量和破坏应力仍比正常人的腱索（成年）低至少一个数量级。透射电子显微镜显示胶原蛋白核心周围的弹性蛋白鞘和与胶原蛋白原纤维相关的蛋白聚糖丝的存在。在动态加载的结构中，胶原蛋白原纤维更长，排列更紧密。动态应变产生了具有良好机械性能和超微结构的替代组织工程材料。该项目证明了定向胶原凝胶收缩可用于体外制备二尖瓣腱索。

著录项

  • 作者

    Shi, Yaling.;

  • 作者单位

    Cleveland State University.;

  • 授予单位 Cleveland State University.;
  • 学科 Engineering Biomedical.
  • 学位 D.Eng.
  • 年度 2003
  • 页码 190 p.
  • 总页数 190
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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