Abstract 4165: Influence of halogens in squaraine dye on optoacoustic signal

Abstract

Abstract Optoacoustic imaging has grown in clinical relevance due to inherent advantages in sensitivity, resolution, and contrast, compared to standard modalities, such as fluorescence. However, guiding principles for development of small molecule contrast agents specific for optoacoustic imaging is lacking. This study assesses the influence of specific structural features of small molecule dyes, specifically squaraine dyes, that result in optoacoustic activity. Through computational models, in vitro testing, and in vivo experimentation this study assesses the effects of halogens on small molecule squaraine dyes to increase optoacoustic signal. By using the aid of our computational model, we decorated the squaraine scaffold with heavy halogenation of squaraines increased optoacoustic activity (2.12 a.u. vs. 0.21 a.u., p<0.001). Density functional theory models suggest the origin of increased optoacoustic signal is due to increases in transition dipole moment which manifested experimentally as increased absorbance in the NIR wavelength range and decreased fluorescence quantum yield, respectively. This study provides an insight into the structure-function relationships that lead to guiding principles for designing optoacoustic-specific contrast agents. Further developments of squaraines and other types of optoacoustic agents will further increase relevance of optoacoustic imaging in a clinical setting. Citation Format: Kavita Belligund, William MacCuaig, Carly Wickizer, Yihan Shao, Lacey R. McNally. Influence of halogens in squaraine dye on optoacoustic signal [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4165.