Preparation of near-infrared photoacoustic imaging and photothermal treatment agent for cancer using a modifiable acid-triggered molecular platform

• Published in: Analyst (London) 2024-05, Vol.149 (11), p.364-372
• Main Authors: Liu, Xiaoming, Xiang, Chunbai, Lv, Yalin, Xiang, Jingjing, Ma, Gongcheng, Li, Changzhong, Hu, Yan, Guo, Chunlei, Sun, Hua, Cai, Lintao, Gong, Ping
• Format: Article
• Language: English
• Subjects: Ablation; Animals; Cancer; Cell Line, Tumor; Continuous radiation; Diamines; Female; Fluorescence; Fluorescent Dyes - chemical synthesis; Fluorescent Dyes - chemistry; Fluorescent Dyes - radiation effects; Humans; Hydrogen-Ion Concentration; Infrared imaging; Infrared lasers; Infrared Rays; Medical imaging; Mice; Mice, Nude; Neoplasms - diagnostic imaging; Neoplasms - therapy; Optical Imaging - methods; Photoacoustic Techniques - methods; Photothermal Therapy - methods; Tumors
• ISSN: 0003-2654; 1364-5528
• DOI: 10.1039/d4an00189c

Ratiometric near-infrared fluorescent pH probes with various p K a values were innovatively designed and synthesized based on cyanine with a diamine moiety. The photochemical properties of these probes were thoroughly evaluated. Among the series, IR-PHA exhibited an optimal p K a value of approximately 6.40, closely matching the pH of cancerous tissues. This feature is particularly valuable for real-time pH monitoring in both living cells and living mice. Moreover, when administered intravenously to tumor-bearing mice, IR-PHA demonstrated rapid and significant enhancement of near-infrared fluorescence and photoacoustic signals within the tumor region. This outcome underscores the probe's exceptional capability for dual-modal cancer imaging utilizing near-infrared fluorescence (NIRF) and photoacoustic (PA) modalities. Concurrently, the application of a continuous-wave near-infrared laser efficiently ablated cancer cells in vivo , attributed to the photothermal effect induced by IR-PHA. The results strongly indicate that IR-PHA is well-suited for NIRF/PA dual-modality imaging and photothermal therapy of tumors. This makes it a promising candidate for theranostic applications involving small molecules. We report here a tunable proton platform for the tumor micro-acid environment that is used for tumor imaging and treatment.