Bio-printing stem cell based and oxygen releasing grafts for myocardial repair

描述（由申请人提供）：估计有80，000，000名美国成年人（三分之一）患有一种或多种心血管疾病（CVD）; 7，900，000人有心肌梗死病史（美国心脏协会）。干细胞治疗是一种很有前途的心肌梗死修复方法，利用干细胞修复受损心脏是当前心脏研究的主流。不幸的是，迄今为止，将干细胞直接注射到梗塞心脏的纤维化区域中的成功有限，这可能是由于干细胞在坏死区域中的低保留和存活，以及所递送的细胞在宿主心脏组织内的有限的心源性分化和功能整合。为了解决这些问题，最近提出了一种组织工程支架方法，涉及使用合成组织支架，其中干细胞接种并随后嵌入生物工程移植框架内。然而，由于合成支架与干细胞结合的经验不足，以及对如何改善支架的几何形状和组成以有利于血管再生和改善移植物微环境以增强干细胞的活力、生长和分化的知识有限，因此取得了有限的成功。我们的建议解决了这些限制与一个新的策略，结合使用可生物降解的弹性体和释氧支架间充质干细胞治疗。为此，我们将使用聚合物静电纺丝和微喷射细胞打印的混合生物打印技术来制造耐用的基于干细胞的多层3D心脏贴片。在这种生物工程构建体中，支架作为有效的干细胞载体和用于肌细胞生长和机电耦合的3-D弹性物理结构。在我们的支架中包含过氧化钙氧释放纳米颗粒改善了微环境，以增强干细胞的存活及其与受损心脏组织的整合。因此，我们提出了四个具体目标：1。制备和表征用于心脏补片的支架材料。2.优化氧气释放颗粒与支架的结合，以获得最大的氧气输送和最小的毒性。3.利用混合制造生物技术制造复合心脏补片。4.对生物工程心脏补片进行体外评价。总的来说，拟议的项目将通过为细胞提供稳定的递送载体和顺从的局部环境来改善目前用于心肌梗死的干细胞治疗，所述细胞增强和调节其增殖和分化以用于基于细胞的组织再生和修复。此外，这一努力有望通过生物打印关键信号肽和其他分子用于修复软组织损伤的支架来改善未来的方法。 公共卫生相关性：估计有80，000，000名美国成年人（三分之一）患有一种或多种心血管疾病（CVD）; 7，900，000人有心肌梗死病史（美国心脏协会）。干细胞治疗是一种很有前途的心肌梗死修复方法，利用干细胞修复受损心脏是当前心脏研究的主流。拟议的项目将改善目前的干细胞治疗心肌梗死提供细胞与稳定的运载工具和一个顺从的局部环境，增强和调节其增殖和分化的细胞为基础的组织再生和修复。

DESCRIPTION (provided by applicant): An estimated 80,000,000 American adults (one in three) have one or more types of cardiovascular disease (CVD); 7,900,000 have a history of myocardial infarction (American Heart Association). Stem cell therapy is a promising approach for myocardial infarction repair, and the use of stem cells to repair a damaged heart is now mainstream in current cardiac research. Unfortunately, thus far direct injection of stem cells into the fibrotic area of infarcted hearts has met with limited success, probably due to the low retention and survival of stem cells in the necrotic areas, together with the limited cardiogenic differentiation and functional integration of delivered cells within the host heart tissue. To solve these problems, a tissue engineered scaffolding method has recently been proposed, involving the use of synthetic tissue scaffoldings with stem cells seeded and subsequently embedded within the bioengineered graft framework. However, limited success has been achieved due to inadequate experience in combining synthetic scaffolds with stem cells and limited knowledge of how to improve the geometry and composition of scaffolding to favor revascularization and improve the graft microenvironment for enhanced viability, growth, and differentiation of stem cells. Our proposal addresses these limitations with a new strategy that combines use of biodegradable elastomeric and oxygen-releasing scaffoldings for mesenchymal stem cell therapy. To this aim, we will use our hybrid bio-printing technology of polymer electrospinning and microjet cell printing to fabricate a durable stem cell based multilayered 3-D cardiac patch. In this bioengineered construct, the scaffold serves as an efficient stem cell carrier and 3-D elastomeric physical structure for myocyte growth and electro-mechanical coupling. The inclusion of calcium peroxide oxygen-releasing nanoparticles in our scaffoldings improves the microenvironment for enhanced survival of stem cells and their integration with the injured cardiac tissue. Therefore, we propose 4 Specific Aims: 1. Prepare and characterize scaffold materials for a cardiac patch. 2. Optimize incorporation of oxygen releasing particles into scaffolds for maximum oxygen delivery and minimal toxicity. 3. Fabricate a composite cardiac patch by using the hybrid fabrication biotechnology. 4. Conduct in vitro evaluation of the bio- engineered cardiac patch. Taken together, the proposed project will improve current stem cell therapy for myocardial infarct by providing cells with a stable delivery vehicle and an amenable local environment that enhances and regulates their proliferation and differentiation for cell-based tissue regeneration and repair. In addition, this effort promises future methodological improvements by bio-printing critical signaling peptides and other molecules for use in scaffolds designed to repair soft tissue injuries. PUBLIC HEALTH RELEVANCE: An estimated 80,000,000 American adults (one in three) have one or more types of cardiovascular disease (CVD); 7,900,000 have a history of myocardial infarction (American Heart Association). Stem cell therapy is a promising approach for myocardial infarction repair, and the use of stem cells to repair a damaged heart is now mainstream in current cardiac research. The proposed project will improve current stem cell therapy for myocardial infarct by providing cells with a stable delivery vehicle and an amenable local environment that enhances and regulates their proliferation and differentiation for cell-based tissue regeneration and repair.