Development of high-resolution molecular imaging of endogenous chromophores with

描述(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物种进行成像，目前高分辨率体积成像无法获得这些生物分子物种。我们计划将泵浦-探测吸收光谱与光学相干层析技术相结合，以发展泵浦-探测光学相干显微镜(PPOCM)。由此产生的成像系统将具有亚细胞分辨率，灵敏度为105分贝，相应的最小可检测浓度为1？M的细胞色素c，假设反射镜为-40分贝。我们预计组织穿透深度将与标准光学相干显微镜相当，后者在口腔上皮中的波长为350m，波长为850 nm。除了分子图像外，该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，它们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)在当地有足够的浓度，可以用PPOCM进行检测。此外，它们的丰富吸收光谱在氧化和还原形式之间发生了显著的变化。这将使测量相对浓度(氧化物/红色)成为可能，从而直接测量血氧饱和度、细胞代谢和药物代谢。 与公共健康相关：我们相信，这里提出的技术进步将为以亚细胞分辨率在体内测量细胞和小动物中的生化浓度和动力学提供宝贵的工具。利用所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起源和治疗的理解，以及对人类非侵入性和微创性诊断的发展。由于所提出的技术不需要在化学或遗传上标记目标分子，因此它具有极大地扩展光学分子成像在临床和研究环境中的影响的强大潜力。

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.