Heat generation on Fe3O4@SiO2@Au core-shell structures using the synergy of an alternating magnetic field and NIR laser light within Ist biological optical window

Abstract

Fe3O4@SiO2@Au heterostructures were prepared using a three-step process that included (I) non-hydrolytic thermal decomposition synthesis of magnetic nanoparticles with cubic morphology, (II) deposition of the amorphous silica shell using wet-chemistry technique and (III) reduction of the chemisorbed gold cations using NaBH4 agent. The energy conversion was performed using the action of the alternating magnetic field (AMF) and NIR laser light (808 nm) under separate and mutual contactless stimulation. It was found that the Fe3O4@SiO2@Au heterostructures are highly responsive to both stimuli with the predominance of the NIR heat-induced mechanism. The dual action of AMF and NIR for optimized parameters is advantageous since heating occurs faster and more efficiently (SAR 1300 W/g). The final desirable temperature can be tuned by the adjustment of the AMF, NIR parameters, and particle concentration. The heterostructures show a cytostatic effect in contact with the breast cancer lines SK-BR-3, MCF-7, and MDA-MB-231.