Artificial Stem Cells for Vascular Tissue Engineering

用于血管组织工程的人工干细胞

基本信息

批准号：
9175164
负责人：
David Alan Vorp
金额：
$ 37.54万
依托单位：
UNIVERSITY OF PITTSBURGH AT PITTSBURGH
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-07-01 至 2020-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9175164
关键词：
Address Animals Arteries Autologous Biological Biomedical Engineering Blood Vessels Bypass Caliber Cardiac Cardiovascular Diseases Cattle Cell Culture Techniques Cell Line Cell Proliferation Cells Clinic Clinical Conditioned Culture Media Data Dialysis procedure Effectiveness Elderly Encapsulated Endothelial Cells Engineering Evaluation Exhibits Failure Family Goals Harvest Human Implant In Vitro Innovative Therapy Lower Extremity Measurement Measures Mechanics Mesenchymal Stem Cells Microspheres Modeling Monitor Nature Operative Surgical Procedures Patients Performance Population Procedures Process Property Rattus Residencies Risk Seeds Serum Smooth Muscle Myocytes Stem cells System Technology Testing Time Tissue Engineering Translations Vascular Graft Work antiangiogenesis therapy base cardiovascular risk factor cell motility cell type cost diabetic diabetic patient high risk in vivo individual patient innovation metaplastic cell transformation monocyte non-diabetic novel paracrine prevent release factor scaffold stem success tissue culture treatment strategy vascular tissue engineering

项目摘要

SUMMARY Vascular grafts that are currently used in small-diameter arterial bypass or in AV access for dialysis are not ideal and have significant failure rates. Tissue-engineered vascular grafts (TEVGs) using autologous mesenchymal stem cells (MSCs) show promise, but have two main limitations that may prevent their clinical translation. First, patients at high risk for cardiovascular disease - such as the elderly and diabetics - have dysfunctional MSCs which may not be able to yield a viable TEVG. Second, the use of any cell type that requires extended culture expansion – including MSCs – opens the door to the risk of cellular contamination or transformation, as well as high costs and a substantial waiting time before a TEVG can be fabricated. The overall goal of the proposed work is to develop a novel, clinically-viable, rapidly-fabricated, cell-free TEVG. The overarching hypothesis of this proposal is that secreted factors from human MSCs can be harvested, packaged, and delivered by “artificial MSCs” (artMSCs) that can then replace the paracrine activity of the MSCs in our TEVG. Three specific aims will address our hypotheses: Aim 1: Develop “artificial stem cells” comprised of families of degradable and tunable microspheres loaded with conditioned media from human MSCs. The goal of the artMSCs is to replace the need for cells in our TEVG, but maintain their critical secreted factors. We expect that we can encapsulate and time-release the soluble factors from biologically active human MSC using PLGA microspheres. We will validate this by using the released factors to drive vascular cell migration and proliferation. Aim 2: Tune the artMSCs in order to most optimally replace the time course of MSC secretory activity and residency within an implanted TEVG. This aim will have two parts: A) An in-vivo time course evaluation of MSC-based TEVGs in a rat model, monitoring presence of implanted MSCs and timing of host SMC and endothelial cell recruitment and remodeling. B) Utilize this timing information to fabricate discrete families of artMSCs that will each release their cargo at different times. We expect the net effect of our artMSC families to approximate the paracrine activity of actively secreting MSC present within the remodeling TEVG. Aim 3: Test the in vivo efficacy of a TEVG comprised of our artMSCs. For this aim, we will seed the families of artMSCs into biodegradable scaffolds and evaluate them as a TEVG in a rat model. We expect that a microsphere-loaded, acellular scaffold will be at least as effective as a TEVG as a scaffold loaded with MSCs. The TEVGs will be assessed by metrics of success including patency and an artery-like composition. An innovative therapy based on secreted factors from standardized human MSC cell lines (i.e., from healthy patients) would offer a uniform treatment strategy from patient to patient than an inherently variable autologous cell-based strategy. The cell-free nature of our approach is more easily translatable to the clinic, and the cost and time spent harvesting cells from individual patients would be eliminated.

概括目前在小直径动脉旁路或AV进入透析的血管移植物不是理想并且具有明显的故障率。使用自体的组织工程血管移植（TEVG）间充质干细胞（MSC）表现出希望，但有两个主要局限性，可以阻止其临床翻译。首先，患心血管疾病风险高的患者（例如，糖尿病患者）患有功能失调的MSC可能无法产生可行的TEVG。第二，使用任何单元格需要扩展的培养膨胀（包括MSC）为蜂窝污染的风险打开了大门转型，高成本和大量的等待时间，然后才能制造出Tevg。拟议的工作的总体目标是开发一种新颖的，临床可行的，快速制作的，无细胞的TEVG。这该提议的总体假设是可以收获人类MSC的分泌因素，包装，并由“人造MSC”（ARTMSC）交付，然后可以替换我们的tevg中的MSC。三个具体目标将解决我们的假设：目标1：开发可降解和可调微球系列的“人造干细胞” 来自人类MSC的条件媒体。 ARTMSC的目的是取代我们的单元格需求 tevg，但要保持其关键的分泌因素。我们希望我们可以封装并释放时间使用PLGA微球从生物活性人类MSC中的可溶性因子。我们将通过使用驱动血管细胞迁移和增殖的释放因素。目标2：调整ARTMSC，以最佳地替换MSC分泌活动的时间过程和居住在植入的Tevg中。此目标将有两个部分：a）体内时间课程评估大鼠模型中基于MSC的TEVG，监测植入的MSC的存在以及宿主SMC和内皮细胞募集和重塑。 b）利用这些定时信息来构建离散家庭 ARTMSC将在不同时间释放其货物。我们希望我们的ArtMSC家庭的净效应能够近似在重塑TEVG中主动分泌MSC的旁分泌活性。 AIM 3：测试我们ARTMSC的TEVG完成的体内效率。为此，我们将看到家人将ARTMSC纳入可生物降解的脚手架中，并将其作为大鼠模型中的TEVG评估。我们期望负载的微球支架至少与装有MSC的支架一样有效。 TEVG将通过成功指标进行评估，包括通畅和类似动脉的组成。一种基于标准化人类MSC细胞系的分泌因素的创新疗法（即健康的患者）将提供从患者到患者的统一治疗策略，而不是固有的可变基于自动细胞的策略。我们方法的无细胞性质更容易翻译成诊所从单个患者那里收集细胞所花费的成本和时间将被消除。