A two-in-one Janus NIR-II AIEgen with balanced absorption and emission for image-guided precision surgery

Abstract

Fluorescence imaging in the near-infrared II (NIR-II, 1000–1700 nm) region opens up new avenues for biological systems due to suppressed scattering and low autofluorescence at longer-wavelength photons. Nonetheless, the development of organic NIR-II fluorophores is still limited mainly due to the shortage of efficient molecular design strategy. Herein, we propose an approach of designing Janus NIR-II fluorophores by introducing electronic donors with distinct properties into one molecule. As a proof-of-concept, fluorescent dye 2 TT- m, o C6B with both twisted and planar electronic donors displayed balanced absorption and emission which were absent in its parent compound. The key design strategy for Janus molecule is that it combines the merits of intense absorption from planar architecture and high fluorescence quantum yield from twisted motif. The resulting 2 TT- m, o C6B nanoparticles exhibit a high molar absorptivity of 1.12 ⨯10 4 M −1 cm −1 at 808 nm and a NIR-II quantum yield of 3.7%, displaying a typical aggregation-induced emission (AIE) attribute. The highly bright and stable 2 TT- m, o C6B nanoparticles assured NIR-II image-guided cancer surgery to resect submillimeter tumor nodules. The present study may inspire further development of molecular design philosophy for highly bright NIR-II fluorophores for biomedical applications.

Mitochondria-Targeting Chemodynamic Therapy Nanodrugs for Cancer Treatment

“…The PTFHD nanoplatforms lead to the local high temperature of mitochondria site under the irradiation of near-infrared laser (808 nm), which greatly promoted the rate of the Fenton reaction and damages the mitochondria. The second near-infrared (1,000–1,350 nm, NIR-II) has deeper tissue penetration and higher maximum allowable exposure than the first near-infrared (750–1,000 nm, NIR-I) light ( Wang et al, 2021e ; Liu et al, 2021 ; Zhang et al, 2021 ). Very recently, Li et al (2021c) developed mitochondria-targeted MoS 2 @PDA-Fe@PEG/TPP nanosheets (MPFPT NSs) for the combination therapy of NIR-II-activated PTT and CDT.…”

Aggregation‐Induced Emission Nanoprobes Working in the NIR‐II Region: From Material Design to Fluorescence Imaging and Phototherapy

“…One example using an AIE nanoprobe as a contrast agent to afford image‐guided surgery was reported by Liu et al. [ 127 ] The Janus molecule 2TT‐ m,o C6B (Figure 5c) was designed with strong absorption and emission (NIR‐II QY = 3.7%) that are much higher than those of ICG. To demonstrate the feasibility of the as‐prepared AIE nanoprobes in differentiating stubborn tumors, a peritoneal carcinomatosis‐bearing mouse model was utilized due to the presence of numerous tumor modules with different sizes in the peritoneal cavity.…”

Recent Progresses in NIR-I/II Fluorescence Imaging for Surgical Navigation

“…(G) Chemical structure of IR-BEMC6P and the conjugate plan of IR-BEMC6P@TATE. Adapted with permission from Liu et al (2021) . (H) H1 : NIR-II imaging of the IR-BEMC6P@TATE injection after being blocked by the TATE peptide only.…”

“…Guided by NIR-II imaging and white light, Chen et al conducted a tumor excision surgery using an NIR-II fluorophore (IR-BEMC6P, λ ex / λ em , 808 nm/1,025 nm) conjugating octreotate (TATE) peptide with outstanding optical and biological properties, such as high quantum yield (1.8%), rapid renal excretion, and minimal hepatic uptake ( Figure 11G ) ( Liu et al, 2021 ). The AR42J tumor mice injected with a blockage dose of the free IR-BEMC6P without conjugation of TATE showed a very low tumor fluorescence signal, proving the specific tumor-targeting ability of IR-BEMC6P@TATE ( Figure 11H1 ).…”

“…Tang et al synthesized the Janus NIR-II molecule 2TT-m, oC6B, further wrapped in the amphiphilic polymer DSPE-PEG 2000 affording 2TT-m, oC6B nanoparticles (λ ex /λ em , 777 nm/1,059 nm) for tumor NIR-II image-guided surgery ( Figure 12A ) ( Liu et al, 2021 ). For manifesting the feasibility of 2TT-m, oC6B NPs to distinguish the stubborn tumor, the peritoneal carcinomatosis–bearing murine model was used because of the presence of a lot of tumor modules of different scales in the peritoneal cavity.…”