Development of spin probes for cell-tagging and oximetry

描述（由申请人提供）：氧是生物系统中最重要的分子之一，因为它作为反应物或产物参与了大量的生化过程。这种元素存在于大多数生物分子中，对生物体至关重要，在细胞呼吸和活细胞线粒体的电子传递链中起着至关重要的作用。由于氧气供应或利用的改变，任何氧水平的不平衡都可能影响代谢稳态并导致病理生理。因此，一种评估和跟踪组织氧水平变化的方法对于我们理解发病机制和制定有效的策略来纠正这种不平衡的能力至关重要。这将需要能够量化组织氧合水平的方法，具有良好的空间和时间分辨率。理想情况下，这些测量应通过微创或非侵入性手段获得。因此，本提案的总体目标是开发安全的、可植入的氧传感探针（OxyChips），用于电子顺磁共振（EPR）血氧测量，可用于临床应用。探针将被设计为植入感兴趣的组织中，允许通过非侵入性手段从同一部位重复测量组织氧合。这种新型EPR探针将基于氧敏感颗粒探针嵌入可透氧生物相容性底物聚二甲基硅氧烷（PDMS）。使用这种方法，各种形状、大小和尺寸的OxyChip植入物将被制造和表征。还将测试探针的健壮性，以确保它们按预期执行。然后将在几种与临床相关的人类疾病动物模型中进行生物相容性测试和探针适用性的验证。提出了以下具体目标：1)颗粒EPR探针的封装和OxyChips的制备；2)胶囊化EPR颗粒的生物稳定性和生物相容性评价；3)氧晶片的毒性、免疫反应和安全性评价；4)氧晶片的体内植入和在临床相关疾病动物模型中的测试。从这些设备中获得的信息将更好地了解各种代谢和疾病状态（例如癌症和周围血管疾病），并有助于制定有关治疗和治疗的有效临床决策。本提案的长期目标是开发可植入的氧传感探针，用于临床电子顺磁共振（EPR）血氧测定。氧存在于大多数生物分子中，这些生物分子对生物体至关重要，在正常和改变的生理过程中都起着重要作用。一旦植入，新的探针将允许重复，无创测量组织中的氧浓度。该探针可用于跟踪肿瘤组织的生长和/或死亡、外周动脉疾病和肌肉萎缩的进展以及伤口愈合反应。

DESCRIPTION (provided by applicant): Oxygen is one of the most important molecules in biological systems since it is involved as either a reactant or a product in a vast number of biochemical processes. The element is found in most biomolecules that are essential to living organisms, and plays a crucial role in cellular respiration and the electron transport chain in the mitochondria of living cells. Any imbalance in oxygen levels, which can occur due to altered supply or utilization of oxygen, may affect metabolic homeostasis and lead to pathophysiology. Thus, a means by which to evaluate and track changes in tissue oxygen levels will be of paramount importance in our ability to understand the mechanisms of pathogenesis and to develop effective strategies to correct the imbalance. This would require methods capable of quantifying the levels of tissue oxygenation with good spatial and temporal resolution. Ideally, these measurements should be obtained through minimally invasive or noninvasive means. Thus, the overall objective of this proposal is to develop safe, implantable oxygen-sensing probes (OxyChips) for electron paramagnetic resonance (EPR) oximetry that can be used in clinical applications. The probes will be designed to be implanted in the tissue of interest, permitting repeated measurements of tissue oxygenation from the same site by noninvasive means. This new class of EPR probes will be based on oxygen-sensitive particulate probes embedded in an oxygen-permeable biocompatible substrate, polydimethylsiloxane (PDMS). Using this approach, OxyChip implants of various shapes, sizes, and dimensions will be fabricated and characterized. The robustness of the probes will also be tested to ensure that they will perform as expected. Biocompatibility testing and validation of the probe applicability will then be performed in several clinically-relevant animal models of human disease. The following specific aims are proposed: 1) Encapsulation of particulate EPR probes and fabrication of OxyChips; 2) Biostability and biocompatibility evaluation of encapsulated EPR particulates; 3) Toxicity, immunological response, and safety evaluation of OxyChips, and 4) In vivo implantation and testing of OxyChips in clinically-relevant animal models of disease. The information gained from these devices will provide a better understanding of various metabolic and disease states (e.g. cancer and peripheral vascular disease) and help in making effective clinical decisions regarding treatment and therapy. The long-term objective of this proposal is to develop implantable, oxygen-sensing probes for use in clinical electron paramagnetic resonance (EPR) oximetry. Oxygen is found in most biomolecules that are essential to living organisms, and plays a role in a number of processes in both normal and altered physiology. Once implanted, the new probes will permit repeated, noninvasive measurement of oxygen concentration in tissues. The probes could be used to track growth and/or death of tumor tissues, progression of peripheral arterial disease and muscular atrophy, and wound healing response.