Stable
Organic Photosensitizer Nanoparticles with
Absorption Peak beyond 800 Nanometers and High Reactive Oxygen Species
Yield for Multimodality Phototheranostics
Effective
multimodality phototheranostics under deep-penetration
laser excitation is highly desired for tumor medicine, which is still
at a deadlock due to lack of versatile photosensitizers with absorption
located in the long-wavelength region. Herein, we demonstrate a stable
organic photosensitizer nanoparticle based on molecular engineering
of benzo[c]thiophene (BT)-based photoactivated molecules
with strong wavelength-tunable absorption in the near-infrared region. Via molecular design, the absorption and singlet oxygen
generation of BT molecules would be reliably tuned. Importantly, the
nanoparticles with a red-shifted absorption peak of 843 nm not only
show over 10-fold reactive oxygen species yield compared with indocyanine
green but also demonstrate a notable photothermal effect and photoacoustic
signal upon 808 nm excitation. The in vitro and in vivo experiments substantiate good multimodal anticancer
efficacy and imaging performance of BT theranostics. This work provides
an organic photosensitizer nanoparticle with long-wavelength excitation
and high photoenergy conversion efficiency for multimodality phototherapy.