Carbonic anhydrase inhibitor-decorated semiconducting oligomer nanoparticles for active-targeting NIR-II fluorescence tumor imaging

Abstract

Second near-infrared window (NIR-II) fluorescence imaging has shown great potential in the field of bioimaging. To achieve a better imaging effect, variety of NIR-II fluorescence probes have been designed and developed. Among them, semiconducting oligomers (SOs) have shown unique advantages including high photostability and quantum yield, making them promise in NIR-II fluorescence imaging. Herein, we design a semiconducting oligomer nanoparticle (ASONi) for NIR-II fluorescence imaging of tumor. ASONi is composed of an azido-functionalized semiconducting oligomer (ASO) as the NIR-II fluorescence emitter, and a benzene sulfonamide-ended DSPE-PEG (DSPE-PEG-CAi) as the stabilizer. Owing to the benzene sulfonamide groups on the surface, ASONi has the capability of targeting the carbonic anhydrase IX (CA IX) of MDA-MB-231 breast cancer cell. Compared with ASON without benzene sulfonamide groups on the surface, ASONi has a 1.4-fold higher uptake for MDA-MB-231 cells and 1.5-fold higher breast tumor accumulation after i.v. injection. The NIR-II fluorescence signal of ASONi can light the tumor up within 4 h, demonstrating its capability of active tumor targeting and NIR-II fluorescence imaging.

High-Affinity NIR-Fluorescent Inhibitors for Tumor Imaging via Carbonic Anhydrase IX

“…Since the discovery of CAIX as a hypoxic tumor biomarker, − numerous studies have used antibodies, small-molecule compounds, and nanoparticles conjugated to fluorescent or radioactive elements designed both for tumor imaging and cancer treatment. − ,,,− Several small-molecule probes have reached clinical trials. For instance, 18 F-VM4-037, a small-molecule radiotracer developed on the sulfonamide pharmacophore, a derivative of the CA ligand ethoxzolamide, failed to localize the ccRCC tumor as it had a high background in the kidney and liver .…”