Near-infrared II nanomaterials for hypoxic TME diagnosis and therapy

Hypoxic tumor microenvironments (TME) drive cancer aggression and therapy resistance, necessitating precise diagnostic and therapeutic strategies. Near-Infrared II (NIR-II) nanomaterials have emerged as transformative tools for addressing hypoxic TME challenges, leveraging deeper tissue penetration, minimal scattering, and reduced autofluorescence. This review systematically summarizes the recent advancements in NIR-II nanomaterials, focusing on their applications in imaging and therapy for hypoxic tumors. NIR-II-based imaging techniques, including fluorescence, photoacoustic, and multimodal imaging, provide high sensitivity and resolution for detecting hypoxic regions, aiding in early diagnosis and personalized treatment planning. In therapeutic applications, NIR-II materials enhance the efficacy of photothermal therapy, photodynamic therapy, and photo-Fenton therapy, all of which overcome the limitations of traditional therapies in hypoxic areas. The combination of NIR-II materials with other treatment modalities holds promise for more effective cancer treatments. This review also discusses the challenges in the current research landscape, including the preparation, scalability, and clinical translation of NIR-II materials. It highlights the need for continued innovation to optimize these materials for broader clinical applications. Overall, NIR-II nanomaterials represent a significant step forward in addressing the challenges posed by hypoxic tumors, with the potential to revolutionize cancer diagnosis and therapy.