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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：
9276786
负责人：
David Alan Vorp
金额：
$ 38.05万
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/9276786
关键词：
Address Alpha Cell Animal Sources Arteries Autologous Biological Biological Factors Biomedical Engineering Biomimetics Blood Vessels Bypass Caliber Cardiac Cattle Cell Line Cell Proliferation Cell Survival Cells Clinic Clinical 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 Mesenchymal Stem Cells Microspheres Modeling Monitor Nature Operative Surgical Procedures Pathologic Patient risk Patients Performance Periodicity Procedures Process Rattus Recruitment Activity Residencies Risk Secretory Cell Seeds Serum Smooth Muscle Myocytes Standardization Stem cells System Technology Testing Time Tissue Engineering Tissue Viability Vascular Graft Work angiogenesis base cardiovascular disorder risk cardiovascular risk factor cell motility cell type clinical translation cost diabetic diabetic patient high risk high risk population in vivo individual patient innovation mechanical properties 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.

概括目前用于小直径动脉旁路或透析 AV 通路的血管移植物不属于理想且具有显着的故障率。使用自体血管移植物进行组织工程（TEVG）间充质干细胞（MSC）显示出前景，但有两个主要局限性可能会阻碍其临床应用翻译。首先，心血管疾病高危患者——例如老年人和糖尿病患者—— 功能失调的 MSC 可能无法产生可行的 TEVG。其次，使用任何细胞类型需要扩展培养物扩增——包括间充质干细胞——打开了细胞污染风险的大门，或者转型，以及制造 TEVG 之前的高成本和大量等待时间。这拟议工作的总体目标是开发一种新颖的、临床上可行的、快速制造的无细胞 TEVG。这该提案的总体假设是可以收获人类 MSC 的分泌因子，由“人工 MSC”（artMSC）包装和递送，然后可以取代 MSC 的旁分泌活性我们的 TEVG 中的 MSC。三个具体目标将解决我们的假设：目标 1：开发由可降解和可调节微球家族组成的“人工干细胞” 使用来自人类 MSC 的条件培养基。 artMSC 的目标是替代我们对细胞的需求 TEVG，但保持其关键的分泌因子。我们期望能够封装并及时释放使用 PLGA 微球从具有生物活性的人 MSC 中提取可溶性因子。我们将通过使用来验证这一点释放的因子驱动血管细胞迁移和增殖。目标 2：调整 artMSC，以最优化地替代 MSC 分泌活动的时间过程和在植入的 TEVG 内居住。该目标将分为两个部分：A) 体内时间过程评估大鼠模型中基于 MSC 的 TEVG，监测植入 MSC 的存在以及宿主 SMC 和的时间内皮细胞募集和重塑。 B) 利用该时序信息来制造离散系列 artMSC 将在不同时间释放其货物。我们预计 artMSC 系列的净效应近似重塑 TEVG 中存在的主动分泌 MSC 的旁分泌活性。目标 3：测试由我们的 artMSC 组成的 TEVG 的体内功效。为了这个目标，我们将为家庭播种将 artMSC 转化为可生物降解的支架，并在大鼠模型中将其作为 TEVG 进行评估。我们期望一个装载微球的无细胞支架至少与装载 MSC 的 TEVG 一样有效。 TEVG 将通过成功指标进行评估，包括通畅性和动脉样成分。一种基于标准化人类 MSC 细胞系（即来自健康的患者）将为患者提供统一的治疗策略，而不是固有的变量基于自体细胞的策略。我们方法的无细胞性质更容易转化为临床，从个体患者身上采集细胞所花费的成本和时间也将被消除。