Photosensitizer loaded PEG-MoS2–Au hybrids for CT/NIRF imaging-guided stepwise photothermal and photodynamic therapy

Abstract

In this study, we developed X-ray computed tomography (CT)/near-infrared fluorescence (NIRF) imaging for visually guiding the photothermal therapy (PTT)/photodynamic therapy (PDT) of antitumor nanocomposites (PEG-MoS₂–Au–Ce6), by adsorbing chlorin e6 (Ce6) to the gold nanoparticle (AuNPs)-decorated molybdenum disulfide (PEG-MoS₂) nanosheets. The NIR photosensitizer Ce6 was adsorbed onto the PEG-MoS₂–Au hybrids via π–π stacking and hydrophobic interactions, where Ce6 remained in its quenched state due to the surface plasmon resonance (SPR) capacity of AuNPs, as well as the coupling interaction with PEG-MoS₂ nanosheets. However, Ce6 was dequenched and boosted strong NIR fluorescence signals after being released from the surface of PEG-MoS₂–Au hybrids upon heat generation, thus producing the PDT effect for anti-tumor therapy. Moreover, the PEG-MoS₂ nanosheets and Ce6 in the PEG-MoS₂–Au–Ce6 nanocomposites could be further used for CT and NIRF dual-modal imaging, respectively. In vitro NIR-triggered drug release studies indicated that the PEG-MoS₂–Au–Ce6 nanocomposites rapidly release the drug around the tumor site under the photothermal effect. Therefore, this dual-modality nanosystem simultaneously enables precise cancer diagnosis and therapy.