Photoacoustic imaging is an emerging modality that allows for optical contrast at typically ultrasonic depths up to a few centimeters. Inherently a molecular imaging modality, photoacoustic imaging contrast is proportionate to optical absorption, dependent on molecular structure, of photoabsorbers within a tissue of interest. Furthermore, as photoacoustic imaging is an optical imaging modality, multiwavelength photoacoustic imaging allows for resolving of individual chromophores based on their associated absorption spectra. In living tissue, endogenous photoacoustic contrast is dominated by oxygenated and deoxygenated hemoglobin. Therefore, to examine other molecular targets, exogenous contrast agents are critically needed. Here, antibody-indocyanine green (ICG) conjugates are discussed for their ability to undergo near infrared shifts in optical absorption in vivo once bound to their cellular molecular targets and internalized. These shifts allow for highly sensitive and specific spectroscopic photoacoustic molecular imaging due to suppression of both endogenous hemoglobin signal and signal from freely circulating agent. Synthesis and characterization of antibody-ICG conjugates, in vitro analysis of optical absorption shifts, and an extensive, multi-control, in vivo study to differentiate breast carcinomas and ductal carcinomas in situ from normal mammary epithelium in a murine model of breast cancer development are described. Leveraging antibody-ICG contrast agents and their dynamic optical absorption spectra with photoacoustic imaging may allow for earlier detection of cancers in screening and intraoperative scenarios.

Dynamic optical absorption from antibody-indocyanine green conjugates for specific spectroscopic photoacoustic molecular imaging

Macromolecular Chemistry: The Second Century

[Author Benefits](https://scimeetings.acs.org/?utm_source=pubs_content_marketing&utm_medium=website&utm_campaign=0320_MCF_NPI_Launch_Spring_Homepage&ref=pubs_content_marketing)

[How to use SciMeetings](https://storage.googleapis.com/dl.morressier.com/acs/SciMeetings-ACSSpring2020-HowToGuide_M3020-Final.pdf)

[Frequently Asked Questions](https://storage.googleapis.com/dl.morressier.com/acs/SciMtng_ACSNMSp2020_FAQ_M3120_Final.pdf)

ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.