Development of high-resolution molecular imaging of endogenous chromophores with

描述（由申请人提供）：在这里，我们建议开发一种高分辨率光学分子成像系统，能够直接对大量内源生物分子种类进行成像，而这些内源生物分子种类目前无法进行高分辨率体积成像。我们计划在之前将泵浦探针吸收光谱与光学相干断层扫描相结合的成功基础上，开发泵浦探针光学相干显微镜（PPOCM）。由此产生的成像系统将具有亚细胞分辨率，灵敏度为 105 dB，并且假设反射器为 -40 dB，相应的细胞色素 c 的最小可检测浓度为 1 µM。我们预计组织穿透深度与标准光学相干显微镜相当，在 850 nm 波长下口腔上皮的组织穿透深度 >350 µm。除了分子图像之外，系统还将同时获取描绘组织超微结构的光学相干显微镜图像。我们将首先针对普遍存在的血红素蛋白，它在许多生理过程中发挥着重要作用，包括氧运输（血红蛋白、肌红蛋白）、细胞代谢（细胞色素 c）和药物代谢（细胞色素 P450）。许多血红素蛋白（包括列出的那些）以足够的局部浓度存在，以便能够用 PPOCM 进行检测。此外，它们丰富的吸收光谱在氧化形式和还原形式之间变化显着。这将能够测量相对浓度（氧化物/红色），从而直接测量血氧饱和度、细胞代谢和药物代谢。 公共健康相关性：我们相信这里提出的技术进步将为在体内测量细胞和小动物中具有亚细胞分辨率的生化浓度和动态提供宝贵的工具。利用已开发的工具进行进一步的研究和开发可能会促进对人类疾病的起源和治疗的理解以及人类无创和微创诊断的发展。由于所提出的技术不需要对目标分子进行化学或基因标记，因此它具有显着扩大光学分子成像在临床和研究环境中的影响的巨大潜力。

DESCRIPTION (provided by applicant): Here we propose to develop a high-resolution optical molecular imaging system capable of directly imaging a large pool of endogenous biomolecular species, which are currently inaccessible to high-resolution volumetric imaging. We plan to build on our previous success in integrating pump-probe absorption spectroscopy with optical coherence tomography to develop pump-probe optical coherence microscopy (PPOCM). The resulting imaging system will have subcellular resolution with a sensitivity of 105 dB and a corresponding minimum detectable concentration of 1 ¿M of cytochrome c assuming a -40 dB reflector. We expect the tissue penetration depth to be comparable to standard optical coherence microscopy, which is >350 ¿m in oral epithelium at 850 nm. In addition to the molecular image the system will simultaneously acquire the optical coherence microscopy image depicting tissue ultrastructure. We will initially target the ubiquitous heme proteins, which play an important role in numerous physiological processes including oxygen transport (hemoglobin, myoglobin), cellular metabolism (cytochrome c) and drug metabolism (cytochrome P450). Many of the heme proteins (including those listed) exist in sufficient local concentrations to enable detection with PPOCM. In addition, their rich absorption spectra change significantly between oxidized and reduced forms. This will enable the measurement of relative concentrations (oxid/red) leading to direct measures of blood oxygen saturation, cellular metabolism, and drug metabolism. PUBLIC HEALTH RELEVANCE: We believe the technological advances proposed here will provide an invaluable tool for the in vivo measure of biochemical concentration and dynamics in cells and small animals with subcellular resolution. Further research and development utilizing the developed tools may lead to advances in the understanding of the origins and treatment of human disease as well the development of noninvasive and minimally invasive diagnostics in humans. Since the proposed technique does not require tagging of target molecules either chemically or genetically it has a strong potential for dramatically extending the impact of optical molecular imaging in both the clinical and research environment.