No abstract

Highly porous, ferromagnetic glass‐ceramic P40‐Fe3O4 microspheres (125–212 µm) with enhanced cytocompatibility have been manufactured for the first time via a facile, rapid, single‐stage flame spheroidization process. Dispersions of Fe3O4 and Ca2Fe2O5 domains (≈10 µm) embedded within P40 (40P2O5‐16CaO‐24MgO‐20Na2O in mol%) phosphate‐based glass matrices show evidence for remanent magnetization (0.2 Am2 kg−1) and provide for controlled induction heating to a constant level of 41.9 °C, making these materials highly appropriate for localized magnetic hyperthermia applications. Complementary, cytocompatibility investigations confirm the suitability of P40‐Fe3O4 porous microspheres for biomedical applications. It is suggested that the flame‐spheroidization process opens up new opportunities for the development of innovative synergistic biomaterials, toward bone‐tissue regenerative applications.

Highly porous magnetic microspheres are synthesised through a flame spheroidisation process and surface functionalised. Metal–organic frameworks are then grown on the surfaces to produce novel hierarchically porous magnetic framework composites.

The rapid, single-stage, flame-spheroidisation process, as applied to varying Fe3O4:CaCO3 powder combinations, provides for the rapid production of a mixture of dense and porous ferromagnetic microspheres with homogeneous composition, high levels of interconnected porosity and microsphere size control. This study describes the production of dense (35–80 µm) and highly porous (125–180 µm) Ca2Fe2O5 ferromagnetic microspheres. Correlated backscattered electron imaging and mineral liberation analysis investigations provide insight into the microsphere formation mechanisms, as a function of Fe3O4/porogen mass ratios and gas flow settings. Optimised conditions for the processing of highly homogeneous Ca2Fe2O5 porous and dense microspheres are identified. Induction heating studies of the materials produced delivered a controlled temperature increase to 43.7 °C, indicating that these flame-spheroidised Ca2Fe2O5 ferromagnetic microspheres could be highly promising candidates for magnetic induced hyperthermia and other biomedical applications.