Design of functionalized magnetic silica multi-core composite nanoparticles for synergistic magnetic hyperthermia/radiotherapy in cancer cells

Nanomaterials in particular the magnetic nanoparticles (MNPs) offer tremendous potential for cancer treatment due to their unique intrinsic properties. Combining materials with a variety of functional groups, and forming a multifunctional nanosystem to overcome the limitations of monotherapy for cancer treatment has always been a research focus with notable difficulties. Considering the many challenges faced by radiotherapy and hyperthermia, in this study, we designed a rational strategy for magnetic hyperthermia using Fe3O4@SiO2@Sec(2)@FA nanoparticles as a novel nano-radiosensitizer to simultaneously enhance the therapeutic effects of radiotherapy in the future. Fe3O4@SiO2 core-shell structured nanoparticles were synthesized with an appropriate silica layer thickness to maintain good saturation magnetization. The as-prepared Fe3O4@SiO2@Sec(2)@FA nanoparticles had the specific absorption rate (SAR)value of 57 W/g, which was below the clinically acceptable alternating magnetic field value of 4.9 x 10(9) Am(-1)s(-1),indicating good heat generation efficiency (the temperature level delta T=6-10 ?). Moreover, Folate-modified nanoparticles exhibited approximately 6-fold higher cellular internalization of Hela cells with no obvious cytotoxicity for the Hela and MDA-MB-231 cells, and lower cytotoxicity for the HUVECs in a concentration range of 0-150 mu g/mL. In addition, these nanoparticles were modified on the silica surface by L-selenocystine, which could enhance the elimination of tumor cells by producing reactive oxygen species under X-rays, resulting in a novel radiosensitization effect. Therefore, the as-prepared Fe3O4@-SiO2@Sec(2)@FA nanoparticles with good biocompatibility and active targeting would possess synergistic magnetic hyperthermia/radiotherapy effect.

Automated summary

Nanomaterials, especially magnetic nanoparticles (MNPs), have great potential for cancer treatment due to their unique properties. In this study, Fe3O4@SiO2@Sec(2)@FA nanoparticles were designed as a novel nano-radiosensitizer to enhance the therapeutic effects of radiotherapy. These nanoparticles exhibited good heat generation efficiency and active targeting, making them suitable for magnetic hyperthermia/radiotherapy.