Capozza Martina, Blasi Francesco, Valbusa Giovanni, Oliva Paolo, Cabella Claudia, Buonsanti Federica, Cordaro Alessia, Pizzuto Lorena, Maiocchi Alessandro, Poggi Luisa
Università degli Studi di Torino, Dipartimento di Biotecnologie Molecolari e Scienze per la Salute, Via Nizza 52, 10126, Torino, Italy.
Bracco Imaging SpA, Centro Ricerche Bracco, Via Ribes 5, 10010, Colleretto Giacosa, Torino, Italy.
Photoacoustics. 2018 Aug 3;11:36-45. doi: 10.1016/j.pacs.2018.07.007. eCollection 2018 Sep.
PhotoAcoustic Imaging (PAI) is a biomedical imaging modality currently under evaluation in preclinical and clinical settings. In this work, ICG is coupled to an integrin binding vector (ICG-RGD) to combine the good photoacoustic properties of ICG and the favourable αβ-binding capabilities of a small RGD cyclic peptidomimetic. ICG-RGD is characterized in terms of physicochemical properties, biodistribution and imaging performance. Tumor uptake was assessed in subcutaneous xenograft mouse models of human glioblastoma (U-87MG, high αβ expression) and epidermoid carcinoma (A431, low αβ expression). ICG and ICG-RGD showed high PA signal in tumors already after 15 min post-injection. At later time points the signal of ICG rapidly decreased, while ICG-RGD showed sustained uptake in U-87MG but not in A431 tumors, likely due to the integrin-mediated retention of the probe. In conclusion, ICG-RGD is a novel targeted contrast agents for PAI with superior biodistribution, tumor uptake properties and diagnostic value compared to ICG.
光声成像（PAI）是一种目前正在临床前和临床环境中进行评估的生物医学成像模态。在这项工作中，吲哚菁绿（ICG）与整合素结合载体（ICG-RGD）偶联，以结合ICG良好的光声特性和小型RGD环肽模拟物有利的αβ结合能力。对ICG-RGD的物理化学性质、生物分布和成像性能进行了表征。在人胶质母细胞瘤（U-87MG，αβ高表达）和表皮样癌（A431，αβ低表达）的皮下异种移植小鼠模型中评估肿瘤摄取情况。注射后15分钟，ICG和ICG-RGD在肿瘤中就显示出高PA信号。在随后的时间点，ICG的信号迅速下降，而ICG-RGD在U-87MG肿瘤中显示出持续摄取，但在A431肿瘤中则没有，这可能是由于探针的整合素介导的滞留。总之，与ICG相比，ICG-RGD是一种新型的PAI靶向造影剂，具有优异的生物分布、肿瘤摄取特性和诊断价值。
