Novel multispectral optoacoustic tomography contrast agents for evaluation of early response to radiation therapy

Project Summary/Abstract Vascular perfusion is a useful biomarker for assessment of many pathological conditions. Our research will focus on development of superior contrast agents for use with Dynamic Contrast Enhanced (DCE) Multi- Spectral Optoacoustic Tomography (MSOT; also known as photoacoustic imaging (PAI)) to quantitatively measure changes in this parameter to measure early response of solid tumors to radiation therapy. This emerging imaging technology provides outstanding temporal resolution that is critical for estimating kinetic perfusion rates while also providing excellent spatial resolution. However, existing contrast agents for this imaging modality possess serious performance limitations. NIRvana Sciences, Inc. proposes to develop a new contrast agent with enhanced performance in DCE MSOT. This will include modification of existing hydrophobic designs to optimize their water solubility, biocompatibility, and biodistribution attributes for in vivo use. NIRvana’s agents possess sharp, narrow absorption bands in the near-infrared (NIR) spectral window and offer the first multi-color palette of spectrally resolvable narrow spectrum agents for multiplex imaging with MSOT with greater sensitivity. These contrast agents will provide outstanding innovations for evaluation of changes in tumor perfusion by DCE MSOT that can indicate an early response to radiation therapy.Project Narrative/Public Health Relevance NIRvana Sciences proposes to develop a new contrast agent for Dynamic Contrast Enhanced Multi-Spectral Optoacoustic Tomography (DCE MSOT). This new contrast agent will have a sharp, narrow absorption band that is suitable for multiplex imaging, and has greater sensitivity than the commonly used MSOT contrast agents. We will exploit the advantages of this new contrast agent to improve the measurements of tumor vascular perfusion by DCE MSOT, which can gauge the early response to radiation therapy and chemotherapeutic agents in xenograft tumor models, and eventually in patients with cancer.