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，能够直接成像大量内源性生物分子物种，这些物种目前无法进行高分辨率体积成像。我们计划在先前成功的基础上，将泵浦探针吸收光谱与光学相干层析相结合，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，假设反射器为-40 dB，相应的最低可检测浓度为1¿M细胞色素c。我们期望组织穿透深度与标准光学相干显微镜相当，在850 nm的口腔上皮中，组织穿透深度为50 ~ 350 μ m。除了分子图像外，该系统还将同时获得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，它们在许多生理过程中发挥重要作用，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）存在足够的局部浓度，可以用PPOCM检测。此外，它们的富吸收光谱在氧化态和还原态之间变化显著。这将能够测量相对浓度（氧化/红），从而直接测量血氧饱和度、细胞代谢和药物代谢。

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.