Fluorescence lifetime tomography of tumor physiology in small animals

摘要：本提案的目标是推进光学成像系统， 使用荧光寿命的纵向高通量小动物癌症成像 对比度我们将专门推进和验证一种新的时域（TD）寿命- 基于断层扫描技术的两个重要和相关的全身成像 肿瘤转移和血管生成。我们将首先使整个 使用可见光谱中的荧光蛋白（FP）的转移的动物成像 （450nm - 650nm）。FP的终身成像将被应用于跟踪小肿瘤中的转移。 人乳腺癌动物模型。这将允许纵向量化 在活体小鼠中的转移灶的早期阶段比目前可能的其他非- 侵入性技术我们接下来将采用近红外（NIR）（650 nm-850 nm） 具有不同寿命的荧光团，用于研究血管生成和药物递送， 疗法光学成像可以实现整个组织的快速、深层组织（> 1 cm）成像。 具有mm级分辨率的肿瘤体积，可以允许全局定量读出 治疗干预下的肿瘤生理学。光学成像还允许独特的 同时跟踪肿瘤体积内的多个过程的机会， 具有不同寿命的多个荧光团（寿命“多路复用”）。我们将验证 寿命多路复用，以同时跟踪血管生成和药物递送到肿瘤。在 为了实现这一点，我们将使用靶向脉管系统的NIR荧光团和 具有不同寿命的第二NIR荧光团，其标记到赫赛汀上。赫赛汀是一种 靶向人表皮生长因子的抗血管生成和治疗剂 受体2（HER 2/neu），其在人类乳腺癌中过度表达。此外，本发明的目的是， 固有组织光学对比度的NIR光谱将揭示肿瘤血液的变化 体积和氧合，由于治疗和FP表达癌细胞将揭示 肿瘤生长通过同时监测多个生理标志物， 肿瘤的整个体积，这项技术将提供新的见解， 在赫赛汀治疗过程中血管生成和药物递送之间的关系， 开发癌症药物的验证和优化。

ABSTRACT: The goal of this proposal is to advance an optical imaging system for longitudinal, high throughput small animal cancer imaging using fluorescence lifetime contrast. We will specifically advance and validate a novel time domain (TD) lifetime- based tomography technique for whole-body imaging of two important and related phenomena, namely tumor metastasis and angiogenesis. We will first enable whole animal imaging of metastasis using fluorescent proteins (FPs) in the visible spectrum (450nm - 650nm). Lifetime imaging of FPs will be applied to track metastasis in a small animal model of human breast cancer. This will allow longitudinal quantification of metastatic foci in living mice at earlier stages than currently possible with other non- invasive techniques. We will next employ near infra-red (NIR) (650nm - 850nm) fluorophores with distinct lifetimes to study angiogenesis and drug delivery during therapy. Optical imaging can enable rapid, deep tissue (> 1 cm) imaging of the entire tumor volume with mm-scale resolution, which can allow global quantitative readouts of tumor physiology under therapeutic intervention. Optical imaging also allows a unique opportunity for simultaneously tracking multiple processes within the tumor volume using multiple fluorophores with distinct lifetimes (lifetime "multiplexing"). We will validate lifetime multiplexing to track angiogenesis and drug delivery to tumors simultaneously. In order to achieve this, we will use a NIR fluorophore that targets vasculature and a second NIR fluorophore with distinct lifetime that is tagged to herceptin. Herceptin is an anti-angiogenic and therapeutic agent that targets the human epidermal growth factor receptor 2 (HER2/neu), which is over-expressed in human breast cancers. Additionally, NIR spectroscopy of intrinsic tissue optical contrast will reveal changes in tumor blood volume and oxygenation due to therapy, and FP expressing cancer cells will reveal tumor growth. By enabling simultaneous monitoring of multiple physiological markers in the entire volume of tumor, this technology will provide new insights into the interplay between angiogenesis and drug delivery during herceptin treatment, and will allow the validation and optimization of developmental cancer drugs.