A Wireless Laser Speckle and Fluorescence Imager for In vivo Brain Tumor Imaging

描述(申请人提供)：恶性脑肿瘤的异常血管是决定其血流灌注、氧合和治疗反应的关键因素。因此，对临床前脑肿瘤模型的早期微血管结构和功能变化的评估可以为指导新疗法的剂量/时间安排以及提供患者复发和复发的早期可测量迹象提供宝贵的信息。然而，这需要一种活体成像技术，能够评估肿瘤整个生命周期中微血管(~10？m)形态和血流灌注的变化。激光散斑对比成像(LSCI)是一种满足这些要求的光学成像技术，不需要使用外源荧光染料或造影剂。因此，我们建议建立一个最先进的无线头盔LSCI系统来评估体内微血管结构和血流的变化，并结合一个荧光模块来成像转基因脑瘤模型中缺氧诱导的绿色荧光蛋白(GFP)的表达(即9L-HRE-GFP)。我们希望这张头盔图像能够量化脑肿瘤微血管异常的生理后果，如肿瘤血流量减少/间歇性和缺氧增加。由于某些治疗药物(如抗血管内皮生长因子药物、地塞米松等)已经证明可以使肿瘤血管的结构/功能“正常化”并增强药物输送，我们将测试我们的头盔成像仪检测这些变化的能力。作为一个测试案例，我们建议表征临床使用的皮质类固醇，地塞米松，对9L-HRE-GFP脑瘤的‘正常化’作用。我们预计LSCI将显示微血管系统向更正常的结构转变，并伴随着改善的灌注，以及荧光成像显示由于地塞米松导致的血管正常化后缺氧的缓解(即可诱导的GFP表达的减少)。最后，我们期望在这项建议中开发的多模式(即LSCI和荧光)成像和可诱导细胞系(例如9L-HRE-GFP)的创新组合适用于其他涉及病理性血管系统的疾病。总的来说，建议的研究结果将促进对脑肿瘤生物学的基本了解，并为临床前测试建立一个新的平台。 针对人脑肿瘤的新疗法。

DESCRIPTION (provided by applicant): The abnormal vasculature of malignant brain tumors is a critical determinant of their perfusion, oxygenation, and response to therapy. Therefore, the assessment of early structural and functional changes in the microvasculature of pre-clinical brain tumor models can provide invaluable information for directing the dosing/scheduling of new therapies and providing early measurable signs of relapse and recurrence in patients. However, this requires an in vivo imaging technique capable of assessing changes in microvascular (~10¿m) morphology and perfusion over the entire life-cycle of a tumor. Laser speckle contrast imaging (LSCI) is an optical imaging technique that meets these requirements and does not require the administration of exogenous fluorescent dyes or contrast agents. Therefore, we are proposing to build a state-of-the-art wireless, head-mounted LSCI system for assessing in vivo changes in microvascular architecture and perfusion combined with a fluorescence module for imaging hypoxia-induced green fluorescent protein (GFP) expression in a transgenic brain tumor model (i.e. 9L-HRE-GFP). We expect this head-mounted image to enable quantification of the physiological consequences of abnormal brain tumor microvasculature, such as decreased/intermittent tumor blood flow and elevated hypoxia. Since certain therapeutics (e.g. anti-VEGF agents, dexamethasone etc.) have been shown to 'normalize' the structure/function of tumor vessels and enhance drug delivery, we will test the ability of our head-mounted imager to detect these changes. As a test case, we propose to characterize the 'normalizing' effects of the clinically used corticosteroid, dexamethasone, on 9L-HRE-GFP brain tumors. We expect LSCI to reveal a shift in the microvasculature towards a more 'normal' architecture accompanied by improved perfusion, and fluorescence imaging to reveal alleviation of hypoxia (i.e. a reduction in inducible GFP expression) following 'vascular normalization' due to dexamethasone. Finally, we expect the innovative combination of multi-modal (i.e. LSCI and fluorescence) imaging and inducible cell lines (e.g. 9L-HRE-GFP) developed in this proposal to be applicable to other diseases involving the pathological vasculature. Collectively, the results of the proposed studies will promote a fundamental understanding of brain tumor biology and establish a novel platform for the pre-clinical testing of new therapies against human brain tumors.