Imaging epidermal growth factor receptor expression in vivo:: Pharmacokinetic and biodistribution characterization of a bioconjugated quantum dot nanoprobe
Imaging epidermal growth factor receptor expression in vivo:: Pharmacokinetic and biodistribution characterization of a bioconjugated quantum dot nanoprobe
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DOI：
10.1158/1078-0432.ccr-07-1958
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发表时间：
2008-02-01
影响因子：
11.5
通讯作者：
Krishnan, Sunil
中科院分区：
文献类型：
--
作者：
Diagaradjane, Parmeswaran;Orenstein-Cardona, Jacobo M.;Krishnan, Sunil
目的：为了开发和验证用于区分表皮生长因子（EGF）受体（EGFR）过表达肿瘤与周围正常组织的光学成像纳米探针，所述周围正常组织也表达EGFR.Experimental Design：近红外（NIR）量子点（QD）使用硫醇-马来酰亚胺缀合物与EGF偶联以产生EGF-QD纳米探针。在有和没有抗EGFR抗体预处理的情况下，在一组细胞系中评价这些纳米探针和未缀合的QD的体外结合亲和力。结果：EGF-QD与肿瘤细胞的EGFR特异性结合，并与肿瘤细胞的生长和增殖密切相关。体内成像显示EGF-QD纳米探针的三个不同阶段，肿瘤流入（类似于3分钟）、清除（类似于60分钟）和积累（1-6小时）。QD和EGF-QD表现出相当的非特异性快速肿瘤流入和清除，随后在60 min内达到明显的动态平衡。随后（1-6 h），而QD浓度逐渐降低，EGF-QD在肿瘤中逐渐积累。在24小时的延迟成像中，QD和EGF-QD的肿瘤荧光均降低至接近基线水平。离体全器官荧光、组织匀浆荧光和共聚焦显微镜分析证实了EGF-QD在4小时的肿瘤特异性积累。免疫荧光图像显示EGFR表达肿瘤实质内的EGF-QD荧光的弥散共定位与斑片状血管周围隔离的QD.Conclusion：这些结果代表了一个强大的EGFR成像纳米探针的第一个药代动力学特征。全身给予EGF-QD后4小时肿瘤的可测量对比度增强及其随后在24小时的正常化意味着这种纳米探针可以允许EGFR表达的可定量和重复成像。
Purpose: To develop and validate an optical imaging nanoprobe for the discrimination of epidermal growth factor (EGF) receptor (EGFR)-overexpressing tumors from surrounding normal tissues that also expresses EGFR.Experimental Design: Near-infrared (NIR) quantum dots (QD) were coupled to EGF using thiol-maleimide conjugation to create EGF-QD nanoprobes. In vitro binding affinity of these nanoprobes and unconjugated QDs was evaluated in a panel of cell lines, with and without anti-EGFR antibody pretreatment. Serial optical imaging of HCT116 xenograft tumors was done after systemic injection of QD and EGF-QD.Results: EGF-QD showed EGFR-specific binding in vitro. In vivo imaging showed three distinct phases, tumor influx (similar to 3 min), clearance (similar to 60 min), and accumulation (1-6 h), of EGF-QD nanoprobes. Both QD and EGF-QD showed comparable nonspecific rapid tumor influx and clearance followed by attainment of an apparent dynamic equilibrium at similar to 60 min. Subsequently (1-6 h), whereas QD concentration gradually decreased in tumors, EGF-QDs progressively accumulated in tumors. On delayed imaging at 24 h, tumor fluorescence decreased to near-baseline levels for both QD and EGF-QD. Ex vivo whole-organ fluorescence, tissue homogenate fluorescence, and confocal microscopic analyses confirmed tumor-specific accumulation of EGF-QD at 4 h. Immunofluorescence images showed diffuse colocalization of EGF-QD fluorescence within EGFR-expressing tumor parenchyma compared with patchy perivascular sequestration of QD.Conclusion: These results represent the first pharmacokinetic characterization of a robust EGFR imaging nanoprobe. The measurable contrast enhancement of tumors 4 h after systemic administration of EGF-QD and its subsequent normalization at 24 h imply that this nanoprobe may permit quantifiable and repetitive imaging of EGFR expression.