Noninvasive Monitoring of In Situ Oxygenation and Cell Therapy in Infarct Heart

描述（由申请人提供）：心脏病是美国的主要死因。心脏移植是治疗终末期心力衰竭的唯一有效的临床治疗方法，但它只适用于少数患者。将未成熟细胞（如干细胞或成肌细胞）移植到心脏梗死区域，即细胞疗法，似乎是一种有前途的替代策略。成肌细胞来源于腿部骨骼肌组织，可以增殖和分化为功能细胞，从而改善心脏功能。然而，移植的成肌细胞的存活/增殖的概率通常小于1%。严重缺氧（低氧水平）被假设为导致细胞治疗不良结果的因素。因此，迫切需要精确地评估作为心脏组织再生的函数的移植成肌细胞中的氧浓度，特别是细胞内氧合。因此，本研究的目标是开发创新的探针和方法，用于无创监测心肌再生过程中细胞氧合的变化。我们已经开发了一类新的自旋探针，可以直接检测的电子顺磁共振（EPR）光谱/成像具有显着更高的检测灵敏度。探针由锂化萘大环配体的中性自由基堆叠而成。此外，探头可以报告组织氧浓度的绝对值，具有显著的氧灵敏度（优于0.1 Torr）。它们可以在几个月的时间内在封闭的胸部中精确，准确和重复测量心肌氧合。探针可以有效地内化到细胞中以研究细胞增殖和迁移。本提案的目的是利用这些新的探针的存活和增殖的心肌梗死区域的移植细胞的非侵入性监测。该提案具体旨在研究：1。最佳内化程序的建立和自旋探针在成肌细胞中用于细胞追踪和细胞内氧浓度测定的表征; 2.非侵入性监测梗死心脏中移植干细胞的植入、迁移和植入部位的原位氧合; 3.评价缺氧培养或间歇性缺氧/复氧处理的成肌干细胞移植到梗死心脏后的存活、保留、整合和原位氧合的功效。这些创新的探针和技术的可用性将提高我们监测细胞治疗的能力，并为人类心脏病的治疗开辟新的途径。

DESCRIPTION (provided by applicant): Heart disease is the leading cause of death in the United States. Heart transplantation is the only clinically effective therapy for end-stage heart failure, but it is available to only a few patients. Transplantation of immature cells, such as stem cells or myoblasts, in the infarct area of the heart, known as cell therapy, appears to be a promising alternative strategy. The myoblasts, derived from leg skeletal muscle tissue, can proliferate and differentiate into functional cells and thereby improve heart function. However, the probability of survival/proliferation of the transplanted myoblasts is often less than 1%. Severe hypoxia (low oxygen levels) is hypothesized as a factor responsible for the poor outcome of cell therapy. Thus, there is a pressing need to precisely evaluate the oxygen concentration, particularly intracellular oxygenation, in the transplanted myoblasts as a function of cardiac tissue regeneration. Therefore, the goal of the present study is to develop innovative probes and methods for noninvasive monitoring of the changes in the cellular oxygenation during myocardial regeneration. We have developed a new class of spin probes that can be directly detected by electron paramagnetic resonance (EPR) spectroscopy/imaging with markedly higher sensitivity for detection. The probes are composed of stacks of neutral radicals of lithiated naphthalocyanine macrocyclic ligands. In addition, the probes can report absolute values of tissue oxygen concentration with remarkable oxygen sensitivity (better than 0.1 Torr). They enable precise, accurate and repeated measurements of myocardial oxygenation over a period of several months in closed chests. The probes can be efficiently internalized into cells to study cell proliferation and migration. The objective of this proposal is to utilize these novel probes for noninvasive monitoring of the survival and proliferation of the transplanted cells in the infarct area of the myocardium. The proposal specifically seeks to study: 1. Establishment of optimal internalization procedures and characterization of the spin probe in myoblasts for cell-tracking and determination of intracellular oxygen concentration; 2. Noninvasive monitoring of in situ oxygenation at the site of implant, migration, and engraftment of transplanted stem cells in infarcted hearts; 3. Evaluation of the efficacy of myoblast stem cells subjected to hypoxic culture or intermittent hypoxia/reoxygenation on the survival, retention, integration, and in situ oxygenation after their transplantation in the infarcted heart. The availability of these innovative probes and technologies will enhance our ability to monitor cell therapy and should open new avenues in the treatment of heart disease in humans.