Carbon-gold hybrid nanoprobes for real-time imaging, photothermal/photodynamic and nanozyme oxidative therapy

Recently, there is one-fifth of human deaths caused by cancer, leading to cancer treatment remains a hard nut to crack in the medical field. Therefore, as an emerging diagnostic technology, mesoporous nanomaterials-based drug delivery systems integrated diagnosis and therapy have aroused tremendous interest owing to visually targeting effect and superior therapy efficacy compared with traditional cancer treatment. Methods: In this work, we have successfully synthesized mesoporous carbon-gold hybrid nanozyme nanoprobes, whereby mesoporous carbon nanospheres were doped with small gold nanoparticles (OMCAPs) and further stabilized with a complex of reduced serum albumin and folic acid (rBSA-FA). After loading IR780 iodide, the OMCAPs@ rBSA-FA@IR780 nanoprobes were finally accomplished for real-time imaging, photothermal/photodynamic and nanozyme oxidative therapy. Results: Herein, acid oxidized MCAPs possessed large surface area and numerous -COOH groups, which could be used to surface chemically modify numerous targeting molecules and load abundant NIR dye IR780, as well as be acted as photothermal reagents to enhance photothermal therapy effect. In addition, the small Au NPs embedded in OMCAPs were utilized as nanozyme to catalyze H2O2 located in tumor cells to generate OH for intracellular oxidative damage of tumor. Besides, as a commonly used near-infrared (NIR) fluorescence dye, the loaded IR780 iodide could not only apply for real-time imaging, but also effectively enhance photo-thermal therapy (PTT) upon the 808 nm laser irradiation. Moreover, FA molecules could enhance the targeted efficiency of the nanoprobes to the gastric tumor site. According to the systematical study in vitro and in vivo, our fabricated nanoprobes based on carbon-gold hybrid (OMCAPs@ rBSA-FA@IR780) revealed excellent tumor targeting efficacy, long tumor retention and favorably therapeutic effect for tumor.