Superior Near-IR Dyes for Bioimaging

光学成像是对凝胶、传感器和微阵列等生物技术产品进行成像的先进技术。它也越来越多地被用于监测动物的特定分子途径。后一种技术使用的荧光染料可以吸收和发射近红外(NIR)辐射(650-900 nm)，这是一个吸收血红蛋白和水最小的光谱窗口，因此允许光子穿透组织几厘米。这一提议建立在我们最近的发现之上，即方酸轮烷(SRS)是世界上最明亮和最稳定的荧光近红外染料之一。然而，由于它们在水条件下的溶解性很差，它们在生物应用中的有效性仍然是一个挑战，从而限制了它们的商业吸引力。因此，我们的计划是通过在分子结构中引入可溶于水的磺酸盐或膦酸基来改善染料性能。随着进一步的发展，它们很可能成为流行的花菁(Cy5)染料的优秀替代品，并成为非常有用的体外和体内成像应用的探针。第一阶段的总体目标是制备新型的水溶性SR染料，并比较已标记SR或Cy5的各种生物偶联物的性质。本建议的两个具体目的是：1)在MTTI进行SA1-合成含有多个磺酸盐或磷酸基团的新型水溶性SR NHS酯，并与3种不同类型的生物分子、抗体、蛋白质和维生素结合，以与Cy5类似物进行比较。第一个目标是生产含磺酸基或膦酸基的水溶性方酸轮烷探针。随后将方酸轮烷探针以及作为对照探针的Cy5与免疫球蛋白G蛋白、链霉亲和素和叶酸衍生物偶联。2)将在UND进行SA2-体外和体内生物结合物的评价。MTTI开发的SR和Cy5荧光免疫球蛋白和链霉亲和素生物偶联物的体外分子识别性能将使用标准凝胶电泳法和链霉亲和素/生物素方案进行表征。在体外和体内，荧光SR和Cy5叶酸结合物的分子识别性能将通过表达高水平叶酸受体的培养细胞和小鼠异种移植瘤模型的整体动物成像研究来确定。目的是展示在3个不同的体系中使用SR染料标记的分子探针与Cy染料相比的优势。PA-08-050

Optical imaging is an advanced technique to image biotechnology products like gels, sensors, and micro arrays. It is also used increasingly to monitor specific molecular pathways in animals. This latter technique uses fluorescent dyes that absorb and emit near-infrared (NIR) radiation (650-900 nm) a spectral window where hemoglobin and water absorb minimally and therefore allow photons to penetrate several centimeters through tissue. This proposal builds on our recent discovery that squaraine rotaxanes (SRs) are among the world's brightest and most stable fluorescent NIR dyes. However due to their poor solubility under aqueous conditions, their usefulness in biological applications remains a challenge thus limiting their commercial appeal. Our plan is therefore to improve dye performance by introducing water solublizing sulfonate or phosphonic acid groups into the molecular structure. With further development, they are likely to become superior replacements for the popular cyanine (Cy5) dyes and become extremely useful probes for both in vitro and in vivo imaging applications. The overall goal for Phase I is to prepare novel water soluble SR dyes and compare the properties of various bioconjugates that have been labeled with SR or Cy5. The two Specific Aims of the present proposal are: 1) SA1 to be performed at MTTI - Synthesize novel water soluble SR NHS esters incorporating multiple sulfonate or phosphonic acid groups and conjugate to 3 different types of biomolecules, an antibody, a protein and a vitamin for comparison with Cy5 analogues. The first goal is to produce water soluble squaraine rotaxane probes having sulfonate or phosphonic acid groups. This will be followed by conjugation of the squaraine rotaxane probes as well as Cy5 as control probe to IgG protein, streptavidin and a folic acid derivative. 2) SA2 to be perfomed at UND - In vitro and in vivo evaluation of bioconjugates. In vitro molecular recognition performance of the SR and Cy5 fluorescent IgG and streptavidin bioconjugates developed at MTTI will be characterized using standard gel electrophoresis and streptavidin/biotin protocols. In vitro and In vivo molecular recognition performance of fluorescent SR and Cy5 folate conjugates will be determined using cultured cells that express high levels of the folate receptor and in whole animal imaging studies of murine xenograft tumor models. The goal is to demonstrate the advantage of using molecular probes labeled with SR dyes in 3 different systems compared with Cy dyes. PA-08-050