Setting behaviour, mechanical properties and heat generation under alternate current magnetic fields of Fe3O4/TiO2/PMMA composite bone cement

Poly(methyl methacrylate) (PMMA) bone cement has excellent mechanical properties and is injectable; therefore, it is widely used as a filler for bone defects. To realize further effective treatment of bone defects, the design of PMMA cement containing magnetite (Fe₃O₄) and titania (TiO₂), with good bone-bonding properties and potential for application in magnetic hyperthermia treatment, is proposed. The ceramic content of the PMMA composite bone cements was varied from 20 mass% to 45 mass%. The setting behaviour, microstructure, compressive strength and heat generation under alternate current (AC) magnetic fields of the PMMA composite bone cements were evaluated. Determination of the setting temperature and time for the PMMA composite cements revealed that the maximum temperature during setting decreased with increasing Fe₃O₄ and TiO₂ content while the setting time increased. The PMMA composite cements had dense microstructures regardless of the ceramic content. The nominal compressive strength for the samples ranged between 83 MPa and 94 MPa, which is sufficient for bone-filling applications. Furthermore, the PMMA composite cement containing 25 mass% Fe₃O₄ generated heat under AC magnetic field, and its temperature reached 42.3°C after 10 min. Therefore, our findings contribute to the development of novel PMMA bone cements using functional ceramic components.