A highly hemocompatible erythrocyte membrane-coated ultrasmall selenium nanosystem for simultaneous cancer radiosensitization and precise antiangiogenesis.

Radiotherapy is a vitally important strategy for clinical treatment of malignant cancers. Therefore, rational design and development of radiosensitizers that could enhance radiotherapeutic efficacy has attracted tremendous attention. Antiangiogenesis therapy could be a potentially effective strategy to regulate tumor growth and metastasis due to angiogenesis plays a pivotal role for tumor growth, invasion and metastasis to other organs. Herein, we have rationally designed a smart and effective nanosystem by combining ultrasmall selenium nanoparticles and bevacizumab (Avastin™ , Av), for simultaneous radiotherapy and antiangiogenic therapy of cancer. The nanosystem was further coated with red blood cell (RBC) membranes to develop the final construct, RBCs@Se/Av. The RBC membrane coating effectively prolongs the blood circulation time and reduces the elimination of the nanosystem by autoimmune responses. As expected, RBCs@Se/Av, when irradiated with X-ray demonstrated potent anticancer and antiangiogenesis response in vitro and in vivo , as evidenced by strong inhibition of A375 tumor growth in nude mice, without causing any obvious histological damage to the non-target major organs. Taken together, this study demonstrates an effective strategy for design of smart Se-based nanosystem decorated with RBC membrane for simultaneous cancer radiosensitization and precise antiangiogenesis.