TISSUE ENGINEERING OF A CARDIAC PATCH

描述(由申请人提供)： 尽管心血管疾病在过去15年里急剧下降，但在西方世界，心血管疾病仍然是导致死亡和残疾的主要原因。危害心脏功能的成人发病过程包括梗塞、缺血性心脏病、心肌炎和各种特发性心肌病。由于先天性缺陷或疾病过程而导致的肌肉组织局灶性丢失，改变了心脏独特的结构安排，损害了它的功能。人工心肌的工程化片段(心脏补片)可能为重建手术提供几乎无限的材料来源。在我们实验室的初步实验中，我们成功地构建了胎儿和新生儿心肌细胞的小型多层培养，呈现出组织样的组织模式。这些多层培养是由具有细长的杆状细胞形状的肌细胞组成的，但需要进一步培养才能适合移植。这项建议利用了PL在心脏发育、在各种ECM成分上体外培养心肌细胞、培养细胞的体外机械刺激、组织形态特征、概念验证研究方面的经验，并与生物工程同事建立了合作关系。这一建议的具体目的是：1)使用特制的胶原底物和一系列生物反应器来生产适合移植的组织型心肌细胞培养。2)利用形态计量学、生物化学和分子生物学技术对人工心肌和完整心脏进行表征和比较。3)将人造心肌移植到体内可使组织血管化的位置。移植的培养物将通过形态计量学、生化和分子技术与完整心脏的结构和功能进行比较。这些研究的数据将确定产生心脏补片三维组织所需的机械和化学参数。这些培养物将为修复局部心肌损伤提供潜在的生物材料来源。

DESCRIPTION (provided by applicant): Despite a dramatic decline over the past 15 years, cardiovascular disease remains the leading cause of death and disability in the Western world. The adult onset disease processes that compromise cardiac function include, infarction, ischemic heart disease, myocarditis, and a variety of idiopathic cardiomyopathies. The focal loss of muscular tissue, as a result of a congenital defect or a disease process, alters the unique architectural arrangement of the heart and impairs its function. An engineered segment of artificial myocardium (cardiac patch) potentially offers a nearly unlimited source of material for reconstructive surgery. In preliminary experiments from our lab we have successfully constructed small, multilayered cultures of fetal and neonatal cardiac myocytes that exhibit a tissue-like pattern of organization. These multilayered cultures are composed of myocytes that have an elongated, rod-like cell shape, but require further development before they would be suitable for transplantation. This proposal takes advantage of the Pl's experience in cardiac development, in vitro cultivation of cardiac myocytes on various ECM components, in vitro mechanical stimulation of cells in culture, morphological characterization of tissues, proof of concept studies, and established collaborations with bioengineering colleagues. The Specific Aims of this proposal are: 1) To use specially fabricated collagen substrates and a series of bioreactors to produce histotypic cultures of cardiac cells suitable for transplantation. 2) Characterize and compare the artificial myocardium to the intact heart by morphometric, biochemical and molecular techniques. 3) Transplant the artificial myocardium to in vivo locations that will allow vascularization of the tissue. The transplanted cultures will be compared by morphometric, biochemical, and molecular techniques to the structure and function of the intact heart. Data from these studies will identify the mechanical and chemical parameters necessary to produce the three-dimensional organization of the heart patches. These cultures will provide a potential source of biological material for repairing focal damage to the myocardium.