Abstract: Hypoxia occurs when limited oxygen supply impairs physiological functions and is a pathological hallmark of many diseases including cancer and ischemia. Thus, detection of hypoxia can guide treatment planning and serve as a predictor of patient prognosis. Current methods suffer from invasiveness, poor resolution and low specificity. To address these limitations, various hypoxia-responsive probes (HyPs) for photoacoustic imaging are disclosed. The emerging modality converts safe, non-ionizing light to ultrasound waves, enabling acquisition of high-resolution 3D images in deep tissue. The HyPs feature an N-oxide trigger that is reduced in the absence of oxygen by haem proteins such as CYP450 enzymes. Reduction of HyPs produce a spectrally distinct product, facilitating identification via photoacoustic imaging. HyPs exhibit selectivity for hypoxic activation in vitro, in living cells and in multiple disease models in vivo.

Abstract: Hypoxia occurs when limited oxygen supply impairs physiological functions and is a pathological hallmark of many diseases including cancer and ischemia. Thus, detection of hypoxia can guide treatment planning and serve as a predictor of patient prognosis. Current methods suffer from invasiveness, poor resolution and low specificity. To address these limitations, various hypoxia-responsive probes (HyPs) for photoacoustic imaging are disclosed. The emerging modality converts safe, non-ionizing light to ultrasound waves, enabling acquisition of high-resolution 3D images in deep tissue. The HyPs feature an N-oxide trigger that is reduced in the absence of oxygen by haem proteins such as CYP450 enzymes. Reduction of HyPs produce a spectrally distinct product, facilitating identification via photoacoustic imaging. HyPs exhibit selectivity for hypoxic activation in vitro, in living cells and in multiple disease models in vivo.