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

  • Photoacoustics. 2022 Dec 11:29:100437. doi: 10.1016/j.pacs.2022.100437.
Shrishti Singh  1 ,  Giovanni Giammanco  1 ,  Chih-Hsiang Hu  1 ,  Joshua Bush  1 ,  Leandro Soto Cordova  1 ,  Dylan J Lawrence  2 ,  Jeffrey L Moran  1  3 ,  Parag V Chitnis  1  4 ,  Remi Veneziano  1  5
Affiliations
  • 1. Department of Bioengineering, George Mason University, Fairfax, VA 22030, USA.
  • 2. PhotoSound Technologies Inc., Houston, TX 77036, USA.
  • 3. Department of Mechanical Engineering, George Mason University, Fairfax, VA 22030, USA.
  • 4. Center for Adaptive Systems for Brain-body Interactions, George Mason University, Fairfax, VA 22030, USA.
  • 5. Institute for Advanced Biomedical Research, George Mason University, Manassas, VA 20110, USA.
PMID: 36570471 DOI: 10.1016/j.pacs.2022.100437
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 widespread use 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 agents 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 min post-injection with a contrast-to-noise ratio of 2.42.

Keywords
Contrast agent; Imaging probe; Indocyanine green (ICG); J-aggregates (JA); Photoacoustic imaging (PAI).
Products