SPECTRAL AND LIFETIME SHIFTS OF NIR DIAGNOSTIC IMAGING DYES

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目及 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 用于临床使用的探针的选择主要是有机荧光团，因为它们有利的毒性和药代动力学性质。 此外，有机染料可以很容易地与肽或其他官能团结合，这些官能团将与癌细胞受体结合。 有机荧光团也可以用对所讨论的特定细胞具有高亲和力的递送载体标记。 这些荧光探针的开发促进了诊断分子成像，并且通过设计最佳的化学、物理和疾病特异性特性来调节这些荧光团在体内的特异性和长期摄取。 因此，当荧光染料与生物实体缀合时，该染料的生物物理性质可以改变。 因此，这些NIR有机染料构建体的开发始于小动物注射和临床转化之前的体外诊断。 方法 NIR荧光团通常具有彼此重叠或与体内发现的各种发色团重叠的光谱。NIR中的自体荧光有助于增加背景噪声和减少目标到背景测量。因此，在设计荧光探针时，选择具有最佳光谱特性的荧光探针是重要的。 高分辨率光谱系统将用于（i）测量光谱并比较相似的有机染料以选择最佳荧光团，（ii）区分细胞上的标记物质以测量结合机制，以及（iii）检查双标记的荧光物质以进行多波长分子成像。 此外，相敏流动系统将用于（i）测量荧光构建体结合到细胞表面时的寿命，以与未结合的探针进行比较，（ii）检测相敏NIR荧光并将其与荧光团结合细胞上的细胞自发荧光区分开，以及（iii）比较表现出相似发射光谱的竞争性细胞结合荧光团的寿命。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The choice of probes for clinical use is primarily organic fluorophores because of their favorable toxicity and pharmacokinetic properties. Additionally, organic dyes can be easily conjugated to peptides or other functional groups that will bind to cancer cell receptors. Organic fluorophores may also be tagged with a delivery vehicle that has high affinity to a particular cell in question. The development of these fluorescent probes facilitates diagnostic molecular imaging, and the specific and prolonged uptake of these fluorophores in the body is modulated by designing optimum chemical, physical and thus disease-specific properties. Accordingly, when a fluorescent dye is conjugated to a biological entity the photophysical properties of that dye may change. Therefore the development of these NIR organic dye constructs begins with in vitro diagnostics prior to small animal injection and clinical translation. Approach NIR fluorophores often have overlapping spectra either with each other or with various chromophores found in vivo. Autofluorescence in the NIR contributes to increased background noise and reduced target-to-background measurements. When designing a fluorescent probe it is thus important to select one with optimum spectral properties. The high-resolution spectral system will be used to (i) measure spectra and compare similar organic dyes to select the optimum fluorophore, (ii) distinguish between labeled species on the cell for measuring binding mechanisms, and (iii) examine fluorescent species that are dual-labeled for multi-wavelength molecular imaging. Additionally, the phase-sensitive flow system will be used to (i) measure the lifetime of fluorescent constructs when bound to cell surfaces for comparison to the un-bound probe, (ii) detect phase-sensitive NIR fluorescence and discriminate that from cellular autofluorescence on fluorophore bound cells, and (iii) compare the lifetimes of competitive cell-bound fluophores exhibiting similar emission spectra.