Theranostic hollow/mesoporous organosilica nanospheres enhance the therapeutic efficacy of anticancer drugs in metastatic hormone-resistant prostate cancer

Hollow mesoporous silica materials have received intensive interest in the field of cancer treatment owing to their large drug loading capacity, controlled release property and excellent biocompatibility. However, their clinical application is still limited by the complex synthetic process. In this study, a hollow mesoporous organosilica nanosphere (HMON) fabricated by a one-pot pickering emulsion strategy was applied for delivering the anticancer drug doxorubicin (DOX) in order to enhance the therapeutic efficacy in treating metastatic hormone-resistant prostate cancer (HRPC). The obtained HMONs show a high DOX loading efficiency and acid-environment trigged drug release property. Meanwhile, the cytotoxic effects of DOX loaded HMONs (DOX-HMONs) on PC3 cells were evaluated by comprehensive analysis including WST-8 assay, calcein-AM/propidium iodide assay and flow cytometry analysis. Furthermore, the enhanced chemotherapeutic efficacy of the DOX-HMONs was confirmed based on in vivo study in a xenograft tumor model. Hence, it is anticipated that DOX-HMONs can be successfully used to treat HRPC, while decreasing the clinical side effects of free DOX. Furthermore, we confirmed the enhanced ultrasound (US) imaging property of the HMONs by both in vitro and in vivo study. Therefore, the excellent performances of the developed HMONs in both drug delivery and echogenic behavior show the promising potentials for real-time imaging guided chemotherapy.