NIRF/PA/CT multi-modality imaging guided combined photothermal and photodynamic therapy based on tumor microenvironment-responsive nanocomposites.

In this study, we developed a novel chitosan (CS)-controlled and aluminum phthalocyanine chloride (AlPc)-loaded molybdenum disulfide (MoS) nanocomposite as a single nanoplatform (AlPc-MoS@SiO-CS) for near-infrared fluorescence (NIRF), photoacoustic (PA), and X-ray computed tomography (CT) multi-modality imaging-guided photothermal and photodynamic combination therapy of tumors. The MoS nanodot was used as the PA/CT contrast as well as hyperthermal agent. The MoS@SiO nanoparticles prepared by a facile one-pot approach can serve as drug-delivery vehicles to transport the NIR absorbing photosensitizer AlPc within the mesoporous cavities. Meanwhile, a natural cationic polysaccharide, CS, was introduced as a gatekeeper to avoid the premature release of loaded AlPc. What's more, CS as a tumor microenvironment-responsive agent can control the release of loaded drugs to the acidic local environment in the tumor. The in vivo multimodal imaging uncovered that the AlPc-MoS@SiO-CS nanocomposites showed enhanced tumor uptake and diagnosis abilities after intravenous injection. More importantly, the nanocomposites exhibited an evident near-infrared induced photothermal effect in the in vitro and in vivo experiments, which remarkably improved the photodynamic therapy efficiency by accelerating the blood flow and subsequently increasing oxygen supply in the tumor. Taken together, our current work demonstrated a nanoplatform for multimodal imaging guided targeted dual-therapy, which revealed a potential strategy for tumor treatment.