Organic fluorescent nanoprobes with NIR‐IIb characteristics for deep learning

Abstract

Illumination of biological events with near-infrared II sub-channel (NIR-IIb, 1500-1700 nm) enhances the transparency of biological tissues, which is very attractive for deep imaging. Due to the long-wavelength, which reduces optical damage, suppresses autofluorescence, and obviates light scattering, NIR-IIb nanoprobes afford deep tissue penetration with unprecedented spatiotemporal resolution. Hence, NIR-IIb imaging facilitates deep learning and decipherment of biological proceedings in living organisms with astounding high clarity. In comparison to its predecessors in the visible-nearinfrared spectrum, imaging in the NIR-IIb has shown great potential for tissue imaging and extrapolating imaging applications for clinical studies. However, the use of organic fluorescent nanoprobes (OFNPs) in the NIR-IIb region is still rare since it is in its early stages. Thus, herein we aim to survey the recent development of different organic fluorescent nanomaterials with NIR-IIb characteristics, their unique photophysical properties, and their utilization in deep imaging in animal models. Further, practical researches on organic fluorescent nanoprobes with NIR-IIb emission and their transition to clinical applications are highlighted.

Dual-Mode Tumor Imaging Using Probes That Are Responsive to Hypoxia-Induced Pathological Conditions

“… Integration of dual-mode diagnostic agents with therapeutic agents to detect and treat cancer simultaneously. New physical and chemical theories have been used in synthesizing activity-based sensing probes for tumor imaging and therapy [ 399 , 400 ]. This strategy has the potential to minimize patient exposure to chemicals and harmful radiation and increase the efficiency of clinical diagnosis and therapy of cancer, under the right circumstances.…”

Targeted Immunoimaging of Tumor‐Associated Macrophages in Orthotopic Glioblastoma by the NIR‐IIb Nanoprobes

“…A tiny blood vessel with a diameter of 0.77 mm was clearly observed by the NIR-II fluorescence imaging under 980 nm excitation (Figure 4d), illustrating the superior imaging performance achieved by EDB-8.4 NPs in the NIR-IIb window. [48,52,53] Then, the in vivo heating effects under 980 nm excitation were further investigated. As shown in the infrared thermal images of Figure 4b and the corresponding heating curves of Figure 4e, the temperature increment (3.7 °C) caused by 980 nm laser (40 mW cm -2 ) was smaller than that (5.5 °C) caused by 808 nm laser (260 mW cm -2 ) during 15 min irradiation.…”

Two-Photon Absorption: An Open Door to the NIR-II Biological Window?

“…Risks are also associated with the use of inorganic nano-systems including possible toxicity and lack of tissue specificity (Ding et al, 2018;Cao et al, 2019;Zhang et al, 2021a;Chen et al, 2021;Wang et al, 2021). The specific design of NIR-II-absorbing organic probes for bio-imaging has become a key challenge in the discipline, involving the multi-step synthesis of bulky water insoluble structures which often require complex purification (Sordillo et al, 2014a;Hong et al, 2017;Wanderi and Cui, 2022). On the other hand, a number of visible and NIR-Iabsorbing fluorophores exhibiting high quantum yields are commercially available, and have the ability to target a wide range of biological substrates (Carr et al, 2018b).…”