Photosensitizer-conjugated redox-responsive dextran theranostic nanoparticles for near-infrared cancer imaging and photodynamic therapy

Photodynamic therapy (PDT) has emerged as an effective treatment for tumor with minimal nonspecific damage to adjacent healthy tissues. Herein, redox-responsive self-quenching polysaccharide-based theranostic nanoparticles (DEX-SS-Ce6 NPs) were developed for tumor imaging and photodynamic therapy. The dextran–chlorin e6 conjugates (DEX-SS-Ce6) could self-assemble into nanoparticles with uniform sphere shape in aqueous solution and exhibit cellular redox-responsive “OFF/ON” behavior of a fluorescence signal. In addition, the DEX-SS-Ce6 NPs demonstrated an effective cellular uptake property and high phototoxicity upon near-infrared (NIR) laser irradiation. More importantly, DEX-SS-Ce6 NP treated mice presented enhanced tumor targeting ability and improved photodynamic therapeutic efficiency in an in vivo study, compared with free Ce6 treated mice. These results suggest that the DEX-SS-Ce6 NP is a great potential system for tumor imaging and photodynamic therapy.