Tissue protein imaging via second harmonic generaton

描述（由申请人提供）： 组织蛋白质结构，如胶原蛋白和肌动球蛋白产生强烈的二次谐波产生（SHG），并产生对比度产生高分辨率的图像上的激光扫描SHG显微镜活组织。描述SHG的物理学表明，二级和高级蛋白质结构的信息可以从这些蛋白质与特定偏振的光的相互作用中推导出来。激光扫描图像的小型化技术发展迅速。因此，如果有必要的话，一项专门的工程努力很快就可以让医生分析活体患者肌肉和结缔组织的微观和亚微观结构。然而，现在的关键问题是：i）是否可以从SHG图像导出医学上有价值的信息，ii）哪些组织和医学状况最容易分析，iii）用于收集每个组织中的SHG图像的最佳和最简单的手段是什么，iv）SHG的哪些物理性质可能导致对天然蛋白质结构的医学上重要的见解，以及v）精细结构分析所需的光学器件是否适用于活组织的情况。这些问题确定了两条基本路径。首先是表征来自各种组织（包括发育和患病状态）的SHG图像轮廓，以及优化用于从每种蛋白质/组织类型生成SHG对比度图像的参数。第二是从组织蛋白质阵列中分析SHG的分子和物理基础，并测试SHG偏振分析的预测功率以探测组织中蛋白质组装体的亚微观结构。我们的具体目标遵循每一条有希望的道路，并将寻求两者之间的趋同。这些目标是i）测试SHG成像作为诊断模式的效用，以揭示特定组织的组织学/病理学：骨骼肌和心肌、皮肤、软骨、骨和由疾病引起的斑块沉积。ii）使用详细的偏振分析和超分辨率技术来表征组织中SHG的分子源，这些分子的结构状态是这种光学活性的基础，以及它们的光学特性对分子结构变化的响应。iii）确定用于体内组织的SHG成像的理想光学参数。

DESCRIPTION (provided by applicant): Tissue protein structures such as collagen and actomyosin give rise to intense second harmonic generation (SHG), and the resulting contrast yields high-resolution images of live tissues on a laser-scanning SHG microscope. The physics describing SHG indicates that information on secondary and higher-order protein structure may be deduced from the interactions of these proteins with specific polarizations of light. Miniaturized technology to acquire laser-scanning images is developing quickly. Therefore, if warranted, a dedicated engineering effort could soon permit physicians to analyze microscopic and submicroscopic structure in muscle and connective tissues of live patients. However, the key questions now are: i) whether medically valuable information can be derived from SHG images, ii) which tissues and medical conditions are most readily analyzed, iii) what the most optimal and simplest means will be for collecting SHG images in each tissue, iv) which of the physical properties of SHG might lead to medically-important insights into native protein structure, and v) whether the optics required for fine structural analysis will apply in the context of live tissues. These questions define two basic paths. First is characterization of SHG image profiles from various tissues (including developmental and diseased states), and optimization of parameters for generating SHG contrast images from each protein/tissue type. Second is analysis of the molecular and physical basis of SHG from tissue protein arrays, and testing of the predicted power of SHG polarization analysis to probe sub-microscopic structure of protein assemblies in tissues. Our specific aims follow each of these promising paths, and will seek convergence between the two. These aims are i) Test the utility of SHG imaging as a diagnostic modality to reveal histology/pathology of specific tissues: skeletal and cardiac muscle, skin, cartilage, bone, and plaque deposits caused by disease. ii) Use detailed polarization analysis and super-resolution techniques to characterize the molecular sources of SHG in tissues, the structural states of these molecules that underlie this optical activity, and the response of their optical properties to changes in molecular structure. iii) Determine ideal optical parameters for SHG imaging of tissues in vivo.