TiO₂ microspheres containing magnetic nanoparticles for intra‐arterial hyperthermia

Abstract Magnetic microspheres measuring 15–35 µm in diameter are believed to be useful for intra‐arterial hyperthermia. In this study, we attempted to prepare titanium dioxide (TiO₂) microspheres containing magnetic nanoparticles (MNPs). MNP‐containing TiO₂ microspheres with diameters of approximately 30 µm were successfully obtained by sol–gel reaction of titanium tetraisopropoxide in a water‐in‐oil emulsion with added cosurfactant of 1‐butanol and subsequent heat treatment at 200°C. The microspheres showed ferrimagnetism owing to high content of MNPs in approximately 60 wt % and had a low‐crystalline TiO₂ matrix. Furthermore, the agar phantom was heated to above 43°C after approximately 1 min under an alternating magnetic field of 100 kHz and 300 Oe and showed in vitro biocompatibility similar to that of MNP‐free TiO₂ microspheres. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2308–2314, 2017.