EphA2-specific microvesicles derived from tumor cells facilitate the targeted delivery of chemotherapeutic drugs for osteosarcoma therapy.

Despite advances in surgery and chemotherapy, the survival of patients with osteosarcoma (OS) has not been fundamentally improved over the last two decades. Microvesicles (MVs) have a high cargo-loading capacity and are emerging as a promising drug delivery nanoplatform. The aim of this study was to develop MVs as specifically designed vehicles to enable OS-specific targeting and efficient treatment of OS. Herein, we designed and constructed a nanoplatform (YSA-SPION-MV/MTX) consisting of methotrexate (MTX)-loaded MVs coated with surface-carboxyl Fe3O4 superparamagnetic nanoparticles (SPIONs) conjugated with ephrin alpha 2 (EphA2)-targeted peptides (YSAYPDSVPMMS, YSA). YSA-SPION-MV/MTX showed an effective targeting effect on OS cells, which was depended on the binding of the YSA peptide to EphA2. In the orthotopic OS mouse model, YSA-SPION-MV/MTX effectively delivered drugs to tumor sites with specific targeting, resulting in superior anti-tumor activity compared to MTX or MV/MTX. And YSA-SPION-MV/MTX also reduced the side effects of high-dose MTX. Taken together, this strategy opens up a new avenue for OS therapy. And we expect this MV-based therapy to serve as a promising platform for the next generation of precision cancer nanomedicines.