Hailey, Tom and Beth's paper is accepted for publication in ACS Chemical Biology!

Photophysical tuning of N-oxide-based probes enables ratiometric photoacoustic imaging of tumor hypoxia

Hypoxia results when oxygen supply to rapidly growing tumors becomes inadequate to support various physiological processes. This plays a role in tumor metastasis and treatment resistance. Identifying tumor hypoxia can therefore guide treatment planning and predict patient responses. However, hypoxic volumes are heterogeneously dispersed throughout a tumor, making it a challenge to pinpoint them with any degree of accuracy. Herein, we report the development of ratiometric hypoxia probe 1 (rHyP-1), a hypoxia-responsive small-molecule probe designed for reliable hypoxia detection using photoacoustic imaging. Photoacoustic imaging utilizes NIR light to induce the production of ultrasound signals, enabling high-resolution image acquisition at centimeter depths. Together with the ratiometric capability of rHyP-1, reliable hypoxia detection with unprecedented spatial resolution is possible while minimizing error associated with concentration dependence and tissue heterogeneity.