NIR-II fluorescence imaging for diagnostics and therapy of non-cancer diseases

Non-cancerous diseases cover a wide range of medical conditions beyond cancer and are among the leading causes of death globally. Recent advancements in second near-infrared (NIR-II, typically 1000–1700 nm) fluorescence imaging have revolutionized biomedical diagnostics and therapeutics, offering superior tissue penetration, reduced autofluorescence, and high spatiotemporal resolution. This review comprehensively summarises the latest developments in NIR-II fluorescence imaging for the diagnosis and treatment of non-cancerous diseases, including bacterial infections, cardiovascular disorders, liver and kidney diseases, inflammatory conditions, neurodegenerative disorders, metabolic diseases, allograft rejection, hemorrhagic disease, cerebrovascular diseases, and viral infections. Herein, we discuss the design and mechanisms of advanced NIR-II fluorescence probes, such as "always-on", “turn on”, ratiometric, and multimodal imaging probes and their applications in real-time bioimaging and image-guided therapy. Furthermore, we highlight emerging trends in NIR-II-based theranostics and address current challenges related to probe biocompatibility, quantum yield, and clinical translation. In addition, future views, challenges, and potential clinical applications of this NIR-II fluorescence imaging in non-cancerous disorders are also discussed. This review article aims to promote interest in exploring enhanced NIR-II fluorescence imaging for biological and therapeutic applications in non-cancerous disease patients.