Department of Biomedical Engineering, School of Life Science and Technology, China Pharmaceutical University, Nanjing, China.
Contrast Media Mol Imaging. 2012 Jul-Aug;7(4):390-402. doi: 10.1002/cmmi.1464.
A fast clearing hydrophilic near-infrared (NIR) dye ICG-Der-02 was used to constitute tumor targeting contrast agents. Cell adhesion molecule integrin α(v)β(3) served as the target receptor because of its unique expression on almost all sprouting tumor vasculatures. The purpose of this study was to synthesize and compare the properties of integrin α(v)β(3)-targeted, fast clearing NIR probes both in vitro and in vivo for tumor diagnosis. ICG-Der-02 was covalently conjugated to three kinds of RGD peptide including linear, monoeric cyclic and dimeric RGD to form three RGD-based NIR probes. The integrin receptor specificities of these probes were evaluated in vitro by confocal microscopy. The dynamic bio-distribution and elimination ratse were in vivo real-time monitored by a near-infrared imaging system in normal mice. Further, the in vivo tumor targeting abilities of the RGD-based NIR probes were compared in α(v)β(3) -positive MDA-MB-231, U87MG and α(v)β(3)-negtive MCF-7 xenograft mice models. Three RGD-based NIR probes were successfully synthesized with good optical properties. In vitro cellular experiments indicated that the probes have a clear binding affinity to α(υ)β(3) -positive tumor cells, with a cyclic dimeric RGD probe owing the highest integrin affinity. Dynamic bio-distributions of these probes showed a rapid clearing rate through the renal pathway. In vivo tumor targeting ability of the RGD-based porbes was demonstrated on MDA-MB-231 and U87MG tumor models. As expected, the c(RGDyK)(2)-ICG-Der-02 probe displayed the highest tumor-to-normal tissue contrast. The in vitro and in vivo block experiments confirmed the receptor binding specificity of the probes. The hydrophilic dye-labeled NIR probes exhibited a fast clearing rate and deep tissue penetration capability. Further, the α(υ)β(3) receptor affinity of the three RGD-based NIR probes followed the order of dimer cyclic > monomer cyclic > linear. The results demonstrate potent fast clearing probes for in vivo early tumor diagnosis.
一种快速清除的亲水性近红外（NIR）染料 ICG-Der-02 被用作肿瘤靶向对比剂。细胞黏附分子整合素 α(v)β(3) 作为靶受体，因为它在几乎所有新生肿瘤血管中都有独特的表达。本研究旨在合成并比较三种整合素 α(v)β(3)靶向、快速清除的近红外探针的性质，用于肿瘤诊断。ICG-Der-02 通过共价键与三种 RGD 肽（线性、单环和双环）结合，形成三种基于 RGD 的近红外探针。通过共焦显微镜评估这些探针的整合素受体特异性。在正常小鼠体内，通过近红外成像系统实时监测动态生物分布和消除率。此外，还比较了基于 RGD 的近红外探针在整合素 α(v)β(3)阳性 MDA-MB-231、U87MG 和整合素 α(v)β(3)阴性 MCF-7 异种移植小鼠模型中的体内肿瘤靶向能力。成功合成了三种基于 RGD 的近红外探针，具有良好的光学性能。体外细胞实验表明，探针与α(υ)β(3)阳性肿瘤细胞具有明确的结合亲和力，其中双环二聚体 RGD 探针具有最高的整合素亲和力。这些探针的动态生物分布显示出通过肾脏途径快速清除的速率。在 MDA-MB-231 和 U87MG 肿瘤模型上验证了基于 RGD 的探针的肿瘤靶向能力。正如预期的那样，c(RGDyK)(2)-ICG-Der-02 探针显示出最高的肿瘤与正常组织对比。体外和体内阻断实验证实了探针的受体结合特异性。亲水性染料标记的近红外探针具有快速清除率和深组织穿透能力。此外，三种基于 RGD 的近红外探针的整合素 α(v)β(3)受体亲和力顺序为双环二聚体>单环>线性。结果表明，这些快速清除的探针具有用于体内早期肿瘤诊断的潜力。
