Calcium-enriched carbon nanoparticles loaded with indocyanine green for near-infrared fluorescence imaging-guided synergistic calcium overload, photothermal therapy, and glutathione-depletion-enhanced photodynamic therapy.

Combining phototherapy with other treatments has significantly advanced cancer therapy. Here, we designed and fabricated calcium-enriched carbon nanoparticles (Ca-CNPs) that could effectively deplete glutathione (GSH) and release calcium ions in tumors, thereby enhancing the efficacy of photodynamic therapy (PDT) and the calcium overload effect that leads to mitochondrial dysfunction. Due to the electrostatic interaction, π-π stacking interaction, multiple hydrogen bonds, and microporous structures, indocyanine green (ICG) was loaded onto the surface of Ca-CNPs with a high loading efficiency of 44.7 wt%. The obtained Ca-CNPs@ICG can effectively improve the photostability of ICG while retaining its ability to generate singlet oxygen (1O2) and undergo photothermal conversion (Ca-CNPs@ICG vs. ICG, 45.1% vs. 39.5%). In vitro and in vivo experiments demonstrated that Ca-CNPs@ICG could be used for near-infrared fluorescence imaging-guided synergistic calcium overload, photothermal therapy, and GSH depletion-enhanced PDT. This study sheds light on the improvement of 1O2 utilization efficiency and calcium overload-induced mitochondrial membrane potential imbalance in tumor cells.

Boron Dipyrromethene-Based Phototheranostics for Near Infrared Fluorescent and Photoacoustic Imaging-Guided Synchronous Photodynamic and Photothermal Therapy of Cancer.

The regulation of photochemical properties of phototheranostics, especially the absorption, fluorescence, singlet oxygen (1O2) generation, and photothermal conversion efficiency, is a hot research topic. Here, we designed and synthesized four boron dipyrromethene (BODIPY) derivatives with high absorption coefficients and intense fluorescence in the near-infrared (NIR) region. The substituted electron-donating group significantly improved 1O2 generation and fluorescence of BODIPYs, whereas the electron-withdrawing group boosts photothermal conversion. These hydrophobic BODIPYs were further coated with DSPE-PEG-2000 to form water dispersible nanoparticles (NPs). Among these BODIPY NPs, the B-OMe-NPs with methoxyl substituted at the meso-position showed the highest 1O2 generation, a photothermal conversion efficiency of 66.5%, and an NIR fluorescence peak at 809 nm. In vitro and in vivo experiments demonstrated that B-OMe-NPs might be used for NIR fluorescent and photoacoustic imaging-guided photodynamic and photothermal therapy of cancer.

Tumor microenvironment-responsive S-NSs-TPZ-ICG intelligent nanoplatforms for synergistically enhanced tumor multimodal therapy.

Nanosheet carriers loaded with drugs and phototherapeutics are used for effective cancer therapy, but the process remains challenging. Here, we prepared sulfur nanosheets (S-NSs) and then loaded tirapazamine (TPZ) and indocyanine green (ICG) with a loading efficiency of 6.3% and 94%, respectively. The obtained S-NSs-TPZ-ICG exhibits near-infrared (NIR) fluorescence, high 1O2 generation and photothermal conversion capabilities, good biocompatibility, and tumor microenvironment responsiveness. In vivo and in vitro experiments reveal that S-NSs-TPZ-ICG can be selectively decomposed under acidic and H2O2 conditions to release TPZ and ICG, and significantly inhibit tumor growth under laser irradiation without obvious toxic side effects.

Design and Synthesis of Nanosensor Based on Unsaturated Double Bond Functional Carbon Dots for Phenylephrine Detection Using Bromine As a Bridge.

In recent years, carbon dots (CDs) have attracted great research interest in the field of nanochemosensors due to their fascinating optical properties. However, synthesis of CDs with novel recognition groups in a convenient method is still an area to be explored urgently. In this work, we reported a simple strategy to prepare fluorescent CDs with carbon-carbon double bonds (C═C) as the characteristic structure for phenylephrine (PHE) identification and detection. The itaconic acid and polyethylenimine (PEI) were selected as precursors to fabricate highly emissive CDs under the hydrothermal cross-linking and carbonization process. The fluorescence of designed CDs at 465 nm can be effectively quenched by bromine aqueous solution due to the electrophilic addition reaction with the double bonds. On the other hand, the presence of PHE can inhibit fluorescence quenching by bromine-consumption of a substitution reaction. Inspired by the novel findings, a convenient assay for PHE determination was established using the fluorescence of C═C bond functional CDs as an output signal and bromine as a bridge. The method demonstrated here provided a unique way to develop CD-based nanosensors.