Iron oxide nanoparticles as a drug carrier reduce host immunosuppression for enhanced chemotherapy.

Chemotherapy is still regarded as the main modality for cancer treatment. However, it often suppresses the host immune system, resulting in limited therapeutic effects. It is desirable to design a novel chemotherapeutic agent to reduce the level of immunosuppression. Herein, we designed bovine serum albumin (BSA)-bioinspired iron oxide nanoparticles (IONPs) as a nanocarrier to load anticancer drug mitoxantrone (MTX) for enhanced chemotherapy of orthotopic breast cancer. The treatment with IONPs@BSA-MTX complexes increased CD3+CD4+ and CD3+CD8+ T lymphocytes more than free MTX. The complexes effectively restored the host immune system and exhibited a better anticancer efficacy than free MTX. It was worth noting that the BSA-inspired IONPs were a satisfactory contrast agent for magnetic resonance imaging of tumors and lymph nodes. Our work provides a novel strategy for enhanced chemotherapy with low levels of immunosuppression in the treatment of breast cancer and other cancers.