COMBINED TWO PHOTON OPTICAL COHERENCE MICROSCOPY FOR INTRAVITAL FUNCT IMAGING

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。所列机构为中心机构，不一定为研究者机构。该项目涉及一种新型高分辨率功能成像设备的开发。它将双光子显微镜（TPM）和光学相干断层扫描（OCT）结合到一个平台中。这些方法都利用超短脉冲近红外激光技术，并需要光束扫描形成图像。然而，OCT中的信息内容来源于散射光，而TPM信号来源于荧光的非线性电子激发。它们共同构成了活体显微镜中的相衬和荧光叠加图像。但是使用TPM/OCT，可以在组织中0.5-1 mm的深度处形成断层图像。最近，一个法国小组首次证明，设计一个结合这两种方法的系统是可能的。我们建议通过结合关键的光学设计元素来进一步开展这项工作，这些元素将优化我们对癌症相关过程的敏感性。我们的活体功能成像仪将能够同时成像新生血管结构，血流方向/速度，细胞外基质结构（胶原蛋白/弹性蛋白纤维）和细胞氧化还原状态（例如氧化应激）。这些图像将由内在信号形成，即干涉图和双光子激发的自发荧光，而不添加外源染料/探针。然而，该系统也可以与添加的发色团如荧光染料和基因表达探针（GFP等）一起使用。图像将以真实的时间呈现;因此，只需将受试者置于成像台上，即可在模型肿瘤系统中进行活体动物模型研究。此外，该仪器将被构造成可以在体内进行人类皮肤病变的研究，目的是开发一种提供与组织病理学相当的信息的技术。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This project involves the development of a new type of high-resolution functional imaging device. It combines 2-photon microscopy (TPM) and optical coherence tomography (OCT) into a single platform. These methods both utilize ultrashort-pulse near-infrared laser technologies and require beam scanning to form images. However, the information content in OCT is derived from scattered light, whereas TPM signals originate from non-linear electronic excitation of fluorescence. Together, they constitute the intravital microscope equivalent of a phase contrast and fluorescence overlay image in a single cell. But with TPM/OCT, tomographic images can be formed at depths of 0.5-1 mm in tissue. Recently, a French group demonstrated, for the first time, that it is possible to design a system that combines the 2 approaches. We propose to take this work several steps further by incorporating key optical design elements that will optimize our sensitivity to cancer relevant pro cess es. Our intravital functional imager will be capable of simultaneously imaging neovascular structure, blood flow direction/velocity, extracellular matrix structure (collagen/elastin fibers), and cellular redox state (e.g. oxidative stress). These images will be formed from intrinsic signals, i.e. interferograms and 2-photon excited autofluorescence, without the addition of exogenous dyes/probes. However the system can also be used with added chromophores such as fluorescent dyes and gene expression probes (GFP, etc). Images will be rendered in real time; so live animal model studies can be conducted in model tumor systems simply by placing the subject on an imaging stage. In addition, the instrument will be constructed so that studies of human skin lesions can be performed in vivo, with the goal of developing a technique that provides information comparable to histopathology.