Theranostic Nanoprobes with Aggregation‐Induced NIR‐II Emission: from Molecular Design to Biomedical Application

Abstract

The development of fluorophores with other powerful features has received much attention for the diagnosis and treatment of diseases. Nanoprobes (NPs) with aggregation-induced emission (AIE) have demonstrated superior performance in deeper penetration depth with better resolution, higher signal-to-noise ratio, and lower side effects in the second near-infrared window (NIR-II, 1000-1700 nm) than in any other range. Herein, the latest advances in NIR-II AIE NPs in cancer theranostics are summarized. In particular, we focus on the design of multifunctional AIE agents with both strong NIR-II emission and effective photothermal conversion or reactive oxygen species (ROS) production, as well as their translational biomedical applications, including imaging diagnosis, image-guided surgery, and image-guided phototherapy, etc. At the end of this review, the opportunities and challenges of this field are also discussed.

Multifunctional agents based on 3‐dicycanovinylindan‐1‐one acceptor: Molecular design and phototheranostic application

“…Another method to improve IC is to further enhance its electronwithdrawing ability without modifying its ketone group, which could further redshift the excitation wavelength of the obtained agent. The longer excitation wavelengths could not only increase tissue penetration depth, but also improve maximum permissible exposure (MPE) within human body systems [42][43][44], thereby expanding maneuverability for phototherapy applications while enhancing therapeutic effects. To realize this idea, the general strategy is using the halogen atoms (such as F and Cl) with stronger electronegativities instead of the H atoms in IC (Figure 2a presented IC-2F as the example).…”

Thiophene π‐bridge‐based second near‐infrared luminogens with aggregation‐induced emission for biomedical applications

“…To construct NIR-II AIEgens, two crucial factors should be considered: lowering the HOMO (Highest Occupied Molecular Orbital)-LUMO (Lowest Unoccupied Molecular Orbital) bandgap to achieve NIR-II emission and twisting the molecular backbone to maintain AIE characteristics [15,[18][19][20]. Studies have repeatedly proven that thiophene π-bridge, which covalently connects electron donor (D) and electron acceptor (A), is an optimal candidate to design NIR-II AIEgens [21]. First, the electron-rich thiophene derivatives can work as the second D to strengthen the D-A effect.…”

Recent Advances in Photothermal Therapy at Near‐Infrared‐II Based on 2D MXenes

“…b) Scattering coefficient of different biological tissues as a function of the wavelength (400-1600 nm). Reproduced with permission [73]. Copyright 2023, Wiley-VCH.…”