%0 Journal Article %A Sheryl Roberts %A Eshita Khera %A Crystal Choi %A Tejas Navaratna %A Jan Grimm %A Greg M. Thurber %A Thomas Reiner %T Optoacoustic imaging of Glucagon-like Peptide 1 Receptor with a near-infrared exendin-4 analog %D 2020 %R 10.2967/jnumed.120.252262 %J Journal of Nuclear Medicine %P jnumed.120.252262 %X Limitations in current imaging tools have long challenged the imaging of small pancreatic islets in animal models. Here, we report the first development and in vivo validation testing of a broad spectrum and high absorbance near infrared optoacoustic contrast agent, E4x12-Cy7. Our near infrared tracer (E4x12-Cy7) is based on the amino acid sequence of exendin-4 and targets the glucagon-like peptide-1 receptor (GLP-1R). Cell assays confirmed that E4x12-Cy7 has a high binding affinity (IC50 = 4.6 ± 0.8 nM). Using the multi-spectral optoacoustic tomography (MSOT), we imaged E4x12-Cy7 and optoacoustically visualized β-cell insulinoma xenografts in vivo for the first time. In the future, similar optoacoustic tracers that are specific for β-cells and combines optoacoustic and fluorescence imaging modalities could prove to be important tools for monitoring the pancreas for the progression of diabetes. %U https://jnm.snmjournals.org/content/jnumed/early/2020/10/23/jnumed.120.252262.full.pdf