Improved synergic therapeutic effects of chemoradiation therapy with the aid of a co-drug-loaded nano-radiosensitizer under conventional-dose X-ray irradiation.

The goal of this work is to harness the advantages of a targeted hybrid nanostructure, BSA-coated FeO (F)-Au heterodimer, as a radiosensitizer and co-delivery vehicle of chemotherapeutic drugs for enhanced synergic cancer therapy and protection of healthy tissues. F-Au-BSA-MTX-CUR combines the abilities of enhanced X-ray radiation therapy (F-Au), long blood circulation time (BSA), tumor targeting (MTX), enhanced chemotherapy (MTX and CUR), and protection of normal cells against the harmful effects of radiation (CUR). In this work, we present the radioprotective and radiosensitizing effects of CUR on normal tissues and the tumor site, respectively. After technical evaluation, drug loading, drug release behavior, hemolysis assay, transfection efficacy, and cellular uptake studies with fluorescence microscopy, the biosafety and toxicity of the nanostructure was assessed in vitro and in vivo. Also, to confirm its power to improve synergistic chemoradiation therapy in mice, the antitumor effects of the designed treatment plan were assessed in a 4T1-tumor bearing mouse model. The in vivo antitumor effect evaluation interestingly reveals outstanding therapeutic power of the final formulation (F-Au-BSA-MTX-CUR) and further requirement of CUR as a radioprotective. This result importantly revealed the radioprotection effect of CUR. Co-delivery of the chemotherapeutic drugs MTX and CUR, combined with the radiosensitizing effect of the F-Au heterodimer and the radioprotective effect of CUR, showed promising prospects in cancer therapy.