Unique Double Intramolecular and Intermolecular Exciton Coupling in Ethene‐Bridged aza‐BODIPY Dimers for High‐Efficiency Near‐Infrared Photothermal Conversion and Therapy

Abstract

Spatial electronic communications of chromophores are both theoretically and practically fascinating. Despite intramolecular or intermolecular exciton coupling was observed in multichromophoric oligomers and J-aggregates, respectively, it is unusual that they both occur in the same molecule. Herein, ethene-bridged aza-BODIPY dimers with intramolecular exciton splitting have been developed. By encapsulating the dimer into F-127 polymer, J-type aggregated nanoparticles were produced, which showed obvious intermolecular exciton coupling and dramatically redshifted absorption and emission peaks at 936 and 1003 nm, respectively. The fabricated nanoagents have high photothermal conversion ability (η = 60.3 %) and are ultra-photostable, leading to complete tumor ablation with 915 nm laser irradiation. This phototherapeutic nanoplatform through modulating both intra-and intermolecular exciton couplings is a valuable paradigm for developing photothermal agents for tumor treatment.

Mechanochemistry toward Organic “Salt” via Integer‐Charge‐Transfer Cocrystal Strategy for Rapid, Efficient, and Scalable Near‐Infrared Photothermal Conversion

“…It's expected that weaker synergistic effect in D2b-F4TCNQ may have negative influence on its PTC performance. Similar synergistic effect are reported on the double intra-/intermolecular exciton coupling [28] or simultaneous intra-/intermolecular fluorescence quenching [14c] to increase the photothermal efficacy.…”

Long-Wavelength Photoconvertible Dimeric BODIPYs for Super-Resolution Single-Molecule Localization Imaging in Near-Infrared Emission

“…Boron dipyrromethene (BODIPY) , dyes, as powerful fluorescent imaging dyes, feature synthetic versatility and outstanding photophysical and electronic properties; however, they have been much less explored as photoactivatable probes since it is not easy to switch their fluorescence between on and off states. Several BODIPY photocages based on the photoinduced cleavage of a quencher or a chemical cargo from the BODIPY chromophore have been reported. , However, the photocaging mechanism usually complicates detection at the single-molecule level due to the background fluorescence, and it is also difficult to realize the selective photobleaching of the latter in the presence of the former because the former and latter generally absorb in the same spectral window.…”

Photothermal Nanomaterials: A Powerful Light-to-Heat Converter

“…Since silica-cored Au nanoshells served as the first photothermal nanomaterials for clinical use, more and more inorganic agents with strong absorption in the NIR region, high chemical stability, adjustable water solubility, and minimal cytotoxicity have entered clinical trials. , Clinical trials have also been underway for small organic molecules due to their good biodegradability, good repeatability, and simple preparation. , Nevertheless, the major challenges for the clinical implementation of photothermal nanomaterials are the complex metabolism and excretion behaviors . The representative works on PTT with diverse photothermal nanomaterials in recent years − are summarized in Table .…”