Near-infrared luminescence high-contrast in vivo biomedical imaging

Luminescence imaging in biomedical research has allowed new insights into the architecture of pathological tissues, signalling networks and cell interactions, and is now turning into a powerful tool for diagnostics and image-guided surgery. Luminescence in the near-infrared (NIR) window (700–1,700 nm), in particular, exhibits less interaction of scattering and absorption photons with biological tissues than imaging in the visible range, resulting in deeper optical penetration depth and reduced autofluorescence interference, and thus enabling higher imaging contrast. Despite promising preclinical results, few NIR fluorophores have been clinically approved so far. In this Review, we discuss important engineering challenges that need to be addressed to enable successful clinical translation of NIR luminescence imaging, including enhancement of imaging contrast by optimizing fluorescent probe design, reducing tissue autofluorescence and improving local accumulation of the luminescent probes in the body. Luminescence imaging in the near-infrared (NIR) region enables non-radiative, fast-feedback, low-cost and high-contrast in vivo imaging of biological tissues. This Review discusses engineering challenges that need to be addressed to enable clinical translation of NIR luminescence imaging.