In vivo imaging and spectroscopy of pH and thiols status

描述（由申请人提供）： 该提案将为PI提供新的培训和职业方向的重大转变。从基础物理和有机化学领域到应用生物医学成像和光谱学。研究将在OSU生物医学光谱和成像中心进行，这是一个独特的培训环境，具有新兴的最先进的技术，并在实验生理学和细胞生物学方面提供额外的学习机会，以确保P.I.的独立性。总体实验计划将为一组pH和巯基（SH）敏感的氮氧化合物开发新的生物医学成像和光谱应用，这些氮氧化合物先前由P.I.和同事。目前用于活组织和生物体中的pH和SH的空间和时间检测的方法要么具有显著的局限性，要么不存在。因此，这些新方法可能代表了在各种环境中生理监测的突破。实验将侧重于与心脏缺血和缺血再灌注损伤相关的应用。具体目标是：（SA 1）严格评价现有和新合成的pH和SH敏感性氮氧自由基作为体内电子顺磁共振（EPR）应用的功能探针。将研究功能敏感性、生物组织中还原的稳定性和体内/细胞分布能力。还将测试一系列专门设计用于增强这些探头属性的新探头。(SA2)开发基于EPR的功能光谱和成像技术，用于研究活组织中时间和空间分辨的pH和SH含量。初步研究将优化探针管理技术，最大限度地提高空间和强度分辨率，并将毒性降至最低。实验计划使用这些技术来评估一个新的假设：即，pH值诱导的心肌缓冲能力的变化，在预处理过程中开发的，是重要的功能保护心脏在随后的长时间缺血。初步实验证明了这种相对未知的机制的潜在重要性。(SA3)获得成像和医学科学的必要工具和技能，以弥合物理化学，应用生物医学科学和成像技术之间的接口。该项目的成功可能会对生物成像在医学上的未来应用产生重大影响。

DESCRIPTION (provided by applicant): This proposal will provide new training and a significant shift in career direction for the P.I. from fields of fundamental physical and organic chemistry to applied biomedical imaging and spectroscopy. Studies will be performed at the OSU Biomedical Spectroscopy and Imaging Center, a unique training environment with emerging state-of-the art techniques and with additional learning opportunities in experimental physiology and cell biology that will ensure progress toward independence of the P.I. The overall experimental plan will develop new biomedical imaging and spectroscopy applications for a group of pH- and thiol (SH)-sensitive nitroxides, previously synthesized by the P.I. and colleagues. Current methods for spatial and temporal detection of pH and SH in living tissues and organisms either have significant limitations or do not exist. Therefore, these new approaches could represent a breakthrough in physiologic monitoring in a variety of settings. Experiments will focus on applications related to cardiac ischemia and ischemia-reperfusion injury. The specific aims are: (SA1) To critically evaluate existing and newly synthesized pH- and SH-sensitive nitroxides as functional probes for in vivo electron paramagnetic resonance (EPR) applications. Functional sensitivity, stability towards reduction in biological tissues and capacity for in vivo/cellular distribution will be studied. A series of new probes will also be tested which are specifically designed to enhance these probe attributes. (SA2) To develop functional EPR-based spectroscopy and imaging for the investigation of time and spatially-resolved pH and SH content in living tissues. Initial studies will optimize techniques for probe administration, maximization of spatial and intensity resolution and minimization of toxicity. The experiments are planned using these techniques to evaluate a new hypothesis: namely, that pH-induced changes in myocardial buffering capacity, developed during preconditioning, are important in functional protection of the heart during subsequent prolonged ischemia. Preliminary experiments demonstrate the potential importance of this relatively unknown mechanism. (SA3) To obtain the necessary tools and skills in imaging and in medical science to bridge the interface between physical chemistry, applied biomedical sciences and imaging technology. The success of this project may have a significant impact on the future of bioimaging applications to medicine.