NIR-II bioluminescence for in vivo high contrast imaging and in situ ATP-mediated metastases tracing

Bioluminescence imaging has been widely used in life sciences and biomedical applications. However, conventional bioluminescence imaging usually operates in the visible region, which hampers the high-performance in vivo optical imaging due to the strong tissue absorption and scattering. To address this challenge, here we present bioluminescence probes (BPs) with emission in the second near infrared (NIR-II) region at 1029nm by employing bioluminescence resonance energy transfer (BRET) and two-step fluorescence resonance energy transfer (FRET) with a specially designed cyanine dye FD-1029. The biocompatible NIR-II-BPs are successfully applied to vessels and lymphatics imaging in mice, which gives similar to 5 times higher signal-to-noise ratios and similar to 1.5 times higher spatial resolution than those obtained by NIR-II fluorescence imaging and conventional bioluminescence imaging. Their capability of multiplexed imaging is also well displayed. Taking advantage of the ATP-responding character, the NIR-II-BPs are able to recognize tumor metastasis with a high tumor-to-normal tissue ratio at 83.4. Conventional bioluminescence imaging usually operates in the visible region and its performance is limited by strong tissue absorption and scattering. Here, the authors present bioluminescence probes (BPs) with emission in the second near infrared (NIR-II) region, and show the NIR-II-BPs could sensitively recognize tumor metastasis with a high tumor-to-normal tissue ratio.