Time-Resolved Wide-Field Molecular Optical Tomography

 描述（由申请人提供）：尽管新疗法在实验室环境中取得了令人印象深刻的结果，但将其转化为临床的主要障碍是其在体内的次优性能，这主要是由于在实际情况中药物递送效率低下。优化药物递送的主要挑战是非侵入性地定量药物累积/内化和/或监测活体受试者内的受体二聚化。受体二聚化可以通过定量Förster共振能量转移（FRET）成像在体内系统地监测，该成像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来实现。我们提出的成像策略将联合收割机结合这些尖端的方法来断层成像描绘蛋白质-蛋白质相互作用在体内。在我们目前的R21支持和伦斯勒理工学院（RPI）和奥尔巴尼医学院（AMC）之间强大的学术合作伙伴关系的基础上，我们一直在开发国家的最先进的宽场光学层析成像仪器和算法在体内FRET成像在过去的2年。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开发，R 01的总体目标是开发和整合时间分辨宽场分子光学断层扫描的关键技术，并证明其在活体小动物模型中量化受体二聚化的变革能力。随着灵敏度的百倍提高，分辨率和定量的提高以及体内成像速度的加快（<5分钟/帧），我们提出的全身FRET成像工作有望建立一个新的分析工具，具有重要和直接的药物开发应用和超越。该提案协同集成了独特的和强大的创新，在体内FRET成像，特别是解决长期存在的问题，实际实施的时间分辨宽场分子光学断层扫描。高空间分辨率和定量精度将通过利用时间门数据集的基于压缩传感的重建算法来实现。在基于稀疏时间数据模式的新协议中将实现快速采集。将在携带人乳腺癌异种移植物的鼠模型中采用转铁蛋白（Tfn）NIR FRET测定，以建立基于寿命的FRET，从而定量受体二聚化和内化。此外，基于寿命的FRET将用于非侵入性地鉴定具有最佳细胞驻留的Tfn系统以改善药物递送。该项目完成后，我们将展示一种突破性的方法，用于受体二聚化的断层成像，从而直接成像小动物肿瘤中受体介导的细胞内化，提供独特的强大见解和指导，特别是为药物开发和医疗保健带来巨大利益。

 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.