Scaling up the production of magnetic nanoparticles for biomedical applications: cost‐effective fabrication from basalts

We report here the first results on magnetic nanoparticles fabricated from basalt fragments of the eruption that took place in Lanzarote (Canary Islands) between 1730 and 1736, to be used in technologies of biomedicine. This approach was inspired by the strong and extremely stable remanent magnetization of slowly cooled rocks from basaltic lavas containing finely members of the hematite–ilmenite (Fe2O3–FeTiO3) series. Besides, the presence of titanium may promote good biocompatibility and an adequate corrosion resistance, as it does in prosthesis. The green, simple, fast, and cost-effective synthesis of magnetic nanoparticles was attempted using solar vapor-phase condensation. This technique allows the preparation of large volumes of nanoparticles presenting a narrow particle size distribution without purification steps. Alternatively, high-energy ball-milling of rock powder in the presence of organic surfactants was also studied as a potential method to produce, in a one-step approach, large quantities of nanostructured particles for biomedical applications. As a proof of concept, we explore these materials as candidates to be used in hyperthermia therapy, which promotes selective necrosis of cancer cells by raising the temperature of the tissue slightly above 43 oC. Results are correlated to their chemical and structural properties and compared to initial igneous rock characteristics. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)