Mitochondria targeted biomimetic platform for chemo/photodynamic combination therapy against osteosarcoma.

Clinical treatment for osteosarcoma (OS) is still lacking effective means, and no significant progress in OS treatment have been made in recent years. Single chemotherapy has serious side effects and can produce drug resistance easily, resulting poor therapeutic effect. As a modern and non-invasive treatment form, photodynamic therapy (PDT) is widely used to treat diverse cancers. Chemotherapy in combination with PDT is a particularly efficient antitumor method that could overcome the defects of monotherapies. Since mitochondria is a key subcellular organelle involved in cell apoptosis regulation, targeting tumor cells mitochondria for drug delivery has become an important entry point for anti-tumor therapy. Herein, we rationally designed a core-shell structured biomimetic nanoplatform, i.e., D@SLNP@OSM-IR780, to achieve tumor homologous targeting and mitochondria targeted drug release for chemotherapy combined with PDT against OS. Upon 808 nm laser irradiation, D@SLNP@OSM-IR780 exhibited excellent photo-cytotoxicity in vitro. The excellent targeting effect of D@SLNP@OSM-IR780 in tumor tissues produced a tumor inhibition rate of 98.9% in vivo. We further indicated that synergistic chemo-photodynamic effect induced by D@SLNP@OSM-IR780 could activate mitochondria-mediated apoptosis pathway, along with host immune response and potential photothermal effect. On the whole, D@SLNP@OSM-IR780 is revealed to be a promising platform for OS targeted combination therapeutics.