Time-Resolved Wide-Field Molecular Optical Tomography

 描述(申请人提供)：尽管在实验室环境下的新疗法取得了令人印象深刻的结果，但将其转化到临床的一个主要障碍是它们在体内的表现不佳，这主要是由于在实际情况下药物输送效率低下。优化药物传递的一个主要挑战是非侵入性地量化药物在活体受试者体内的积累/内化和/或监测受体二聚体。通过高灵敏度的光学全身成像、压缩传感和近红外(NIR)荧光寿命FRET，可以通过定量Förster共振能量转移(FRET)成像在体内系统地监测受体的二聚化。我们建议的成像策略将结合这些尖端方法来以断层扫描的方式描述体内蛋白质-蛋白质的相互作用。在我们目前的R21支持下，基于伦斯勒理工学院(RPI)和奥尔巴尼医学院(AMC)之间强大的学术合作伙伴关系，我们在过去两年里一直在开发用于活体FRET成像的最先进的广域光学层析成像仪器和算法。我们已经证明了基于近红外荧光团对和寿命传感的定量成像FRET的可行性。为了支持新型受体靶向治疗的发展，R01的总体目标是开发和集成时间分辨广域分子光学断层扫描的关键技术，并展示其在活体小动物模型中量化受体二聚的转化能力。随着灵敏度提高100倍，分辨率和量化提高，体内成像速度加快(&lt；5分钟/帧)，我们提议的全身FRET成像工作承诺建立一种新的分析工具，具有重要和即时的药物开发应用和更广泛的应用。这一提议协同集成了体内FRET成像的独特和强大的创新，特别是解决了时间分辨广域分子光学断层成像在实际实施中长期存在的问题。利用时间门数据集，基于尖端压缩传感的重建算法将获得高空间分辨率和定量精度。基于稀疏时态数据模式的新协议将实现快速捕获。转铁蛋白(TFN)近红外FRET分析将用于荷人乳腺癌移植瘤的小鼠模型，以建立基于寿命的FRET，以量化受体的二聚化和内在化。此外，基于寿命的FRET将被用来非侵入性地识别具有最佳细胞驻留的TFN系统，以改善药物传递。项目完成后，我们将展示一种突破性的受体二聚化断层成像方法，从而直接成像小动物肿瘤中受体介导的细胞内化，提供独特的强大洞察力和指导，将为药物开发特别是整个医疗保健产生巨大好处。

 DESCRIPTION (provided by applicant): Despite impressive results with new therapies in laboratory settings, a major hurdle to their translation into the clinic is their suboptimal performances in vivo largely due to inefficient drug delivery in practical scenarios. A main challenge in optimizing drug delivery is to non-invasively quantify drug accumulation/internalization and/or monitor receptor dimerization within live subjects. Receptor dimerization can be systematically monitored in vivo with quantitative Förster Resonance Energy Transfer (FRET) imaging, enabled by highly-sensitive optical whole body imaging, compressive sensing and near-infrared (NIR) fluorescence lifetime FRET. Our proposed imaging strategy will combine these cutting-edge methodologies to tomographically depict protein-protein interactions in vivo. Under our current R21 support and based on strong academic partnership between the Rensselaer Polytechnic Institute (RPI) and the Albany Medical College (AMC), we have been developing state-of-the-art wide-field optical tomography instrumentation and algorithms for in vivo FRET imaging over the past 2 years. We have demonstrated the feasibility of quantitatively imaging FRET based on NIR fluorophore pair and lifetime sensing. To support the development of novel receptor-targeted therapy, the overall goal of this R01 is to develop and integrate key technologies for time-resolved wide-field molecular optical tomography and demonstrate its transformative ability to quantify receptor dimerization in live small animal models. With a hundred fold increase in sensitivity, improved resolution and quantification as well as accelerated in vivo imaging speed (<5minutes/frames), our proposed whole-body FRET imaging work promises to establish a new analytical tool with important and immediate drug development applications and beyond. This proposal synergistically integrates unique and powerful innovations for in vivo FRET imaging, specifically addressing the longstanding problems of practical implementation for time-resolved wide-field molecular optical tomography. High-spatial resolution and quantitative accuracy will be achieved with cutting-edge compressive sensing based reconstruction algorithms harnessing time-gate datasets. Fast acquisition will be attained in new protocols based on sparse temporal data patterns. Transferrin (Tfn) NIR FRET assays will be employed in a murine model bearing human breast cancer xenografts to establish lifetime-based FRET to quantify receptor dimerization and internalization. Moreover, lifetime-based FRET will be employed to identify non-invasively the Tfn-system with best cellular residency for improved drug delivery. Upon completion of the project, we will have demonstrated a breakthrough methodology for tomographic imaging of receptor dimerization, and hence direct imaging of receptor-mediated cellular internalization in tumors in small animals, offering unique powerful insight and guidance that would generate huge benefits for drug development in particular and healthcare at large.