Real-Time Pharmacokinetics and Biodistribution
NIR-II in vivo imaging allows drug developers to get higher-resolution real-time visualizations of their drug targets using commercially available NIR dyes.
The potential of NIR-II imaging
Small animal optical imaging has become a very important technique for drug screening in pharmacology and drug discovery research. In vivo NIR-II monitoring of pharmacokinetics and biodistribution in real-time enhances and replaces current methods used in the visible and NIR-I wavelengths. Optical imaging in the second biological window has many advantages, which are that it is non-invasive, safe, has a high spatial resolution, and is a low-cost method. It is currently being used in biomolecular detection imaging, drug distribution, metabolic monitoring, and assessing the effectiveness of therapeutic interventions.
Benefit from NIR-I dyes
Compared with traditional NIR-I imaging technology, NIR-II bioimaging technology not only has a deeper imaging depth but can also better avoid background interference, such as spontaneous fluorescence and photon scattering of tissue. Moreover, many commercially available NIR-I dyes can be used as we are learning that their spectral emission extends into the NIR-II region. Hence, already-approved NIR-I dyes can be used not only as biomedical contrast agents but also in the fields of photothermal and photodynamic drug delivery and tracking of the injected drugs.
For the future of targeted therapeutics and drug discovery
NIR-II imaging has the potential to fundamentally impact the development of targeted therapeutics and drug discovery with real-time pharmacokinetic imaging of over a thousand targets simultaneously in a single mouse. It is urgent to understand the pharmacokinetics, track the biodistribution, and study the toxicology of new activity-based sensors in small animals before their translation into clinical uses.