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bioRxiv · 10.1101/2022.09.01.506234

Size-tunable ICG-based contrast agent platform for targeted near-infrared photoacoustic imaging

Singh, S.·Giammanco, G.·Hu, C.-H.·Bush, J.·Cordova, L. S.·Lawrence, D. J.·Moran, J. L.·Chitnis, P. V.·Veneziano, R.
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Abstract

Near-infrared photoacoustic imaging (NIR-PAI) combines the advantages of optical and ultrasound imaging to provide anatomical and functional information of tissues with high resolution. Although NIR-PAI is promising, its wide application is hindered by the limited availability of NIR contrast agents. J-aggregates (JA) made of indocyanine green dye (ICG) represents an attractive class of biocompatible contrast agents for PAI. Here, we present a facile synthesis method that combines ICG and ICG-azide dyes for producing contrast agent with tunable size down to 230 nm and direct functionalization with targeting moieties. The ICG-JA platform has a detectable PA signal in vitro that is two times stronger than whole blood and high photostability. The targeting ability of ICG-JA was measured in vitro using HeLa cells. The ICG-JA platform was then injected into mice and in vivo NIR-PAI showed enhanced visualization of liver and spleen for 90 minutes post-injection with a contrast-to-noise ratio of 2.42.

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Singh, S., Giammanco, G., Hu, C.-H., Bush, J., Cordova, L. S., Lawrence, D. J., Moran, J. L., Chitnis, P. V., Veneziano, R.. 2022-09-04. Size-tunable ICG-based contrast agent platform for targeted near-infrared photoacoustic imaging. https://doi.org/10.1101/2022.09.01.506234

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