Introduction

Inflammation is an important risk-associated component of many diseases and can be diagnosed by molecular imaging of specific molecules. The aim of this study was to evaluate the possibility of targeting adhesion molecules on inflammation-activated endothelial cells and macrophages using an innovative multimodal polyvinyl alcohol-based microbubble (MB) contrast agent developed for diagnostic use in ultrasound, magnetic resonance, and nuclear imaging.

Methods

We assessed the binding efficiency of antibody-conjugated multimodal contrast to inflamed murine or human endothelial cells (ECs), and to peritoneal macrophages isolated from rats with peritonitis, utilizing the fluorescence characteristics of the MBs. Single-photon emission tomography (SPECT) was used to illustrate ^99mTc-labeled MB targeting and distribution in an experimental in vivo model of inflammation.

Results

Flow cytometry and confocal microscopy showed that binding of antibody-targeted MBs to the adhesion molecules ICAM-1, VCAM-1, or E-selectin, expressed on cytokine-stimulated ECs, was up to sixfold higher for human and 12-fold higher for mouse ECs, compared with that of non-targeted MBs. Under flow conditions, both VCAM-1- and E-selectin-targeted MBs adhered more firmly to stimulated human ECs than to untreated cells, while VCAM-1-targeted MBs adhered best to stimulated murine ECs. SPECT imaging showed an approximate doubling of signal intensity from the abdomen of rats with peritonitis, compared with healthy controls, after injection of anti-ICAM-1-MBs.

Conclusions

This novel multilayer contrast agent can specifically target adhesion molecules expressed as a result of inflammatory stimuli in vitro, and has potential for use in disease-specific multimodal diagnostics in vivo using antibodies against targets of interest.

中文翻译：

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用于粘附分子靶向的新型多模态微泡的分子成像。

介绍

炎症是许多疾病的重要风险相关成分，可以通过特定分子的分子成像来诊断。本研究的目的是评估使用一种创新的多模式聚乙烯醇基微泡 (MB) 造影剂靶向炎症激活的内皮细胞和巨噬细胞上的粘附分子的可能性，该造影剂开发用于超声、磁共振和核成像的诊断用途。

方法

我们利用 MBs 的荧光特性评估了抗体偶联多模式对比剂与发炎的小鼠或人内皮细胞 (ECs) 以及从患有腹膜炎的大鼠中分离出的腹腔巨噬细胞的结合效率。单光子发射断层扫描 (SPECT) 用于说明^99m Tc 标记的 MB 在炎症实验体内模型中的靶向和分布。

结果

流式细胞术和共聚焦显微镜显示，靶向抗体的 MBs 与在细胞因子刺激的 ECs 上表达的粘附分子 ICAM-1、VCAM-1 或 E-选择素的结合对于人类来说高出 6 倍，对于人类来说高出 12 倍。小鼠 ECs，与非靶向 MBs 相比。在流动条件下，靶向 VCAM-1 和 E-选择素的 MB 比未处理的细胞更牢固地粘附于受刺激的人类 EC，而靶向 VCAM-1 的 MB 最能粘附于受刺激的小鼠 EC。SPECT 成像显示，与健康对照组相比，在注射抗ICAM-1-MB后，腹膜炎大鼠腹部的信号强度大约增加了一倍。

结论

这种新型的多层造影剂可以特异性靶向由于炎症刺激而在体外表达的粘附分子，并且具有使用针对感兴趣靶标的抗体进行体内疾病特异性多模式诊断的潜力。