BNNT/Fe₃O₄ as a target system for magnetohyperthermia

Full text: Nanostructured materials have been widely studied aiming of biomedical application, primarily for the purpose of carrying drugs or molecules of interest in a tissue or organ selectively. In this context, boron nitride nanotubes (BNNTs), when functionalized with specific moieties could be useful as nanovectors for delivery of proteins, drugs, and also RNAi molecules due to their capacity to be uptake by cells [1]. The introduction of magnetic nanoparticles allows the use of this system as a hyperthermia agent. Thus, once target tumor the material could kill cancer cells through magnetohyperthermia therapy. In this study, magnetite nanoparticles [2] were incorporated into hydroxylated BNNT by means of ultrasound bath and then magnetohyperthermia tests were performed. The system was characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), vibrating sample magnetometry (VSM) and N₂ adsorption. The obtained results indicate that magnetite nanoparticles are linked to the nanotubes through chemical bonding and also that part of them is positioned on the inner of tubes. The magnetic measurements show that coercivity and magnetization were not disturbed after addition of BNNT, and the magnetohyperthermia tests showed that the material exhibits potential as a hyperthermia agent for cancer treatment. References: [1] FERREIRA, T. H. A Novel Synthesis Route to Produce Boron Nitride Nanotubes for Bioapplications. Journal of Biomaterials and Nanobiotechnology, v. 02, n. 04, p. 426–434, 13 out. 2011. [2] ZHIYA, M. Superparamagnetic silica nanoparticles with immobilized metal affinity ligands for protein adsorption. Journal of Magnetism and Magnetic Materials, 301, p. 469-477, 2006. (author)