Recently, nanomedicine without drug carriers has attracted many pharmacists' attention. A novel paclitaxel-s-s-paclitaxel (PTX-s-s-PTX) conjugate with high drug loading (∼78%, w/w) was synthesized by conjugating paclitaxel to paclitaxel by using disulfide linkage. The conjugate could self-assemble into uniform nanoparticles (NPs) with 1,1-dioctadecyl-3,3,3,3-tetramethylindotricarbocyanine iodide (DiR) encapsulated within the core of PTX-s-s-PTX NPs for photothermal therapy (PTT). The DiR-loaded self-assembled nanoparticles (DSNs) had a mean diameter of about 150 nm and high stability in biological condition. A disulfide bond is utilized as a redox-responsive linkage to facilitate a rapid release of paclitaxel in tumor cells. DSNs indicated significant cytotoxicity as a result of the synergetic chemo-thermal therapy. DSNs were featured with excellent advantages, including high drug loading, redox-responsive releasing behavior of paclitaxel, capability of loading with photothermal agents, and combinational therapy with PTT. In such a potent nanosystem, prodrug and photothermal strategy are integrated into one system to facilitate the therapy efficiency.
Keywords: anticancer; disulfide; high drug loading; photothermal therapy; redox responsive.