Repurposing organic semiconducting nanomaterials to accelerate clinical translation of NIR-II fluorescence imaging

Optical imaging possesses important implications for early disease diagnosis, timely disease treatment, and basic medical as well as biological research. Compared with the traditionary near-infrared (NIR-I) window (650–950 nm) optical imaging, the emerging second near-infrared (NIR-II) window optical imaging technology owns the great superiorities of non-invasiveness, nonionizing radiation, and real-time dynamic imaging with the low biological interference, can significantly improve the tissue penetration depth and detection sensitivity, thus expecting to achieve accurate and precise diagnosis of major diseases. Inspired by the conspicuous superiorities, an increasing number of versatile NIR-II fluorophores have been legitimately designed and engineered for precisely deep-tissue mapping-mediated theranostics of life-threatening diseases. Organic semiconducting nanomaterials (OSNs) are derived from organic conjugated molecules with π-electron delocalized skeletons, which show greatly preponderant prospects in the biomedicine field due to the excellent photoelectric property, tunable energy bands, and fine biocompatibility. In this review, the superiorities of NIR-II fluorescence imaging using OSNs for brilliant visualization various of diseases, including tongue cancer, ovarian cancer, osteosarcoma, bacteria or pathogens infection, kidney dysfunction, rheumatoid arthritis, liver injury, and cerebrovascular function, are emphatically summarized. Finally, the reasonable prospects and persistent efforts for repurposing OSNs to facilitate the clinical translation of NIR-II fluorescence phototheranostics are outlined.