Near-Infrared Afterglow Luminescent Aggregation-Induced Emission Dots with Ultrahigh Tumor-to-Liver Signal Ratio for Promoted Image-Guided Cancer Surgery

Abstract

Afterglow imaging through the collection of persistent luminescence after the stopping of light excitation holds enormous promise for advanced biomedical uses. However, efficient near-infrared (NIR)-emitting afterglow luminescent materials and probes (particularly the organic and polymeric ones) are still very limited, and their in-depth biomedical applications such as precise image-guided cancer surgery are rarely reported. Here, we design and synthesize a NIR afterglow luminescent nanoparticle with aggregation-induced emission (AIE) characteristics (named AGL AIE dots). It is demonstrated that the AGL AIE dots emit rather-high NIR afterglow luminescence persisting over 10 days after the stopping of a single excitation through a series of processes occurring in the AIE dots, including singlet oxygen production by AIE luminogens (AIEgens), Schaap’s dioxetane formation, chemiexcitation by dioxetane decomposition, and energy transfer to NIR-emitting AIEgens. The animal studies reveal that the AGL AIE dots have the innate property of fast afterglow signal quenching in normal tissues, including the liver, spleen, and kidney. After the intravenous injection of AGL AIE dots into peritoneal carcinomatosis bearing mice, the tumor-to-liver ratio of afterglow imaging is nearly 100-fold larger than that for fluorescence imaging. The ultrahigh tumor-to-liver signal ratio, together with low afterglow background noise, enables AGL AIE dots to give excellent performance in precise image-guided cancer surgery.

Aggregation‐Induced Emission Properties of Copper Iodide Clusters

“…In recenty ears, the great development of AIE compounds is relatedtomultiple potential applications, including luminescent probes for biomedical imaging and sensing applications, which are under intensive development. [9][10][11][12][13][14][15][16][17][18] Because of their twisted conformations, AIE-active organic molecules usually aggregate into al oosely( defective) packed solid state that facilitates their transformation between differ-ent molecular arrangements. This characteristicc onfers an enhanced sensitivity to externals timuli and, in particular, to mechanical forces onto thesec ompounds.…”

Persistent Chemiluminescent Glow of Phenoxy‐dioxetane Luminophore Enables Unique CRET‐Based Detection of Proteases

“…[61][62][63] Chemiluminescent CRET-based probesf or bioimaging, on the other hand, were not availableu ntil now.T he basic phenomenon of CRET has been utilized for many years, [64] and dioxetane-based bioimaging systems in which CRET takes place were previously reported by us and others. [65][66][67][68][69] However,i nt hese examples, energy transfer was merely used to enhance the signal and/orm odifyt he emission wavelength, while the status of CRET in the system remained unchanged. This work presentst he first dioxetane CRET-based sensor,i nw hich an alteration in the CRET status is responsible for the chemiluminescence readout.…”

In Situ Methylation Transforms Aggregation‐Caused Quenching into Aggregation‐Induced Emission: Functional Porous Silsesquioxane‐Based Composites with Enhanced Near‐Infrared Emission

“…In principle, this is much easier than conventional tailoring wherein one introduces an AIE functional fragment. [17] AIE active [2-(2,6-bis((E)-4-(di-ptolylamino)styryl)-4H-pyran-4-ylidene]malononitrile (M-TPA-DCM) offering NIR emissive properties was synthesized via Knoevenagel reaction allowing a "one-pot" strategy. M-TPA-DCM exhibits intensive emission in aggregated or solid-state due to the AIE effect and perhaps "σ-π" electron donating effects from methyl to TPA thereby promoting AIE and preferable emission of M-TPA-DCM.…”

“…[13] This feature is attributed to inhibition of intramolecular rotation, intermolecular dipole contacts and π-π interactions. [11,14] For example, the ACQ-active fluorophore, 2-[2.6-bis(-4-(diphenylamino)-stryryl-4H-pyranylidene]malono-nitrile (TPA-DCM) possesses a conjugated "D-π-A-π-D" configuration, dual intramolecular charge transfer (ICT) processes, and shows reduced NIR emission when aggregated. [15] To overcome these issues functional groups such as tetraphenylethene (TPE) can be introduced to transform ACQ to AIE.…”