Challenges and Opportunities for Intravital Near-Infrared Fluorescence Imaging Technology in the Second Transparency Window.

The past decade has witnessed rapid technological development on nanoscale probes and imaging optics in the second near-infrared transparency window (NIR-II, 1000-1700 nm). These methods hold great promise for biomedical applications due to their deep penetration through tissues and high fidelity of images. However, applications of these techniques in biomedical research and translational medicine will require a number of issues to be addressed. In this Perspective, we examine the technical challenges for intravital NIR-II fluorescence imaging technology and discuss where the development of this cutting-edge technique fits in the future.