Micro-Thickness Collagen Membranes in Tissue Engineering

组织工程中的微厚胶原膜

• 批准号: 7142308
• 负责人: ROBERT B VERNON
• 金额: $ 27.45万
• 依托单位: BENAROYA RESEARCH INST AT VIRGINIA MASON
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7142308
• 关键词: artery; blood vessels; collagen; coronary artery; culture; density; elastin; human; muscle cells; orientation; sectioning; tissue engineering

DESCRIPTION (provided by applicant): A major problem in coronary bypass treatment for arteriosclerosis is the lack of suitable autogenous replacement vessels in many patients. This proposal explores new technologies to create tissue-engineered blood vessels (TEBVs) that can serve as readily available replacements for coronary arteries. The bulk of the thickness of an artery wall (the media) is comprised of vascular smooth muscle cells (VSMCs) arranged in concentric layers that provide mechanical strength and contractility. In Aim 1, we will construct TEBV media that incorporate a novel, biocompatible, collagen membrane (CM) scaffold that we developed recently. The CMs' high intrinsic strength and capacity to prealign VSMCs in vitro (via microgrooving) could dramatically shorten TEBV fabrication times to a matter of days, rather than the weeks or months required by other methods. CMs populated with confluent, aligned human coronary artery SMCs (HCASMCs) will be wrapped around a mandrel to form a multilamellar tube. Following removal of the mandrel, the TEBV lumen will be seeded with human coronary artery endothelial cells and the TEBV subsequently grown in a bath of nutrient fluid with nutrient fluid also circulated through the TEBV lumen. After specific intervals of culture, the TEBVs will be evaluated for: (i) deposition of extracellular matrix (ECM) by the VSMCs, (ii) structural changes in the CM scaffolds, (iii) survival, orientation and state of differentiation of the VSMCs, (iv) functional endothelialization of the lumen, and (v) mechanical (burst) strength. The resilient protein elastin is abundant in normal artery walls and its absence in most TEBVs results in a lack of elasticity and excessive proliferation of VSMCs which narrows the TEBV lumen. Ultimately, it would be desirable to use the patient's own VSMCs to limit graft rejection. Unfortunately, adult VSMCs synthesize little or no elastin. To address this problem, Aim 2 evaluates ECM deposition, cell survival and orientation, and mechanical properties (burst-strength, stress/strain response) of TEBVs that incorporate adult rat aortic SMCs that produce elevated levels of elastin as a consequence of expression (via viral transduction) of the proteoglycan versican 3. This proposal seeks to develop new approaches and technologies and apply them to an important problem in human health (coronary artery disease). Moreover, data from this work will serve as a foundation for further development of TEBVs. Accordingly, this application is well suited to the purpose of the R21 mechanism.

描述（由申请人提供）：动脉硬化冠状动脉搭桥治疗的一个主要问题是许多患者缺乏合适的自体替代血管。该提案探索了创建组织工程血管（TEBV）的新技术，该血管可以作为冠状动脉的现成替代品。动脉壁（中膜）的大部分厚度由排列成同心层的血管平滑肌细胞（VSMC）组成，提供机械强度和收缩性。在目标 1 中，我们将构建 TEBV 介质，其中包含我们最近开发的新型生物相容性胶原膜 (CM) 支架。 CM 的高内在强度和体外预对准 VSMC（通过微槽）的能力可以将 TEBV 制造时间大大缩短到几天，而不是其他方法所需的几周或几个月。填充有汇合、对齐的人冠状动脉 SMC (HCASMC) 的 CM 将缠绕在心轴上，形成多层管。移除心轴后，TEBV 管腔将接种人冠状动脉内皮细胞，随后 TEBV 在营养液浴中生长，营养液也通过 TEBV 管腔循环。经过特定的培养间隔后，将评估 TEBV 的以下方面：(i) VSMC 的细胞外基质 (ECM) 沉积，(ii) CM 支架的结构变化，(iii) VSMC 的存活、方向和分化状态，（iv）管腔的功能性内皮化，和（v）机械（破裂）强度。正常动脉壁中富含有弹性的弹性蛋白，而大多数 TEBV 中缺乏弹性蛋白会导致 VSMC 缺乏弹性和过度增殖，从而使 TEBV 管腔变窄。最终，希望使用患者自身的 VSMC 来限制移植物排斥。不幸的是，成人 VSMC 合成很少或不合成弹性蛋白。为了解决这个问题，Aim 2 评估了 TEBV 的 ECM 沉积、细胞存活和定向以及机械特性（破裂强度、应力/应变响应），该 TEBV 包含成年大鼠主动脉 SMC，由于表达而产生高水平的弹性蛋白（通过多功能蛋白聚糖 3 的病毒转导）。该提案旨在开发新的方法和技术，并将其应用于人类健康的一个重要问题（冠状动脉疾病）。此外，这项工作的数据将作为 TEBV 进一步开发的基础。因此，该应用非常适合 R21 机构的目的。