Magnetic polymethylmethacrylate cements for hyperthermic cancer treatment

Abstract

Polymethyl methacrylate (PMMA) bone cements have been used for stabilizing bone prostheses and filling cavities due to their suitable mechanical properties. PMMA bone cements, with and without addition of magnetic glass-ceramic (MGC), have been recently investigated for the treatment of bone cancer. The addition of MGC to PMMA bone cements allows for the treatment of cancer via magnetic induction hyperthermia.This PhD thesis focused on the potential of MGC addition to commercial dental and orthopaedic PMMA cements for bone cancer treatment. MGC was prepared by melt-quenching technique at 1550°C. It contained a crystalline magnetic phase embedded in the glass matrix. MGC was mixed with dental and orthopaedic PMMA cements in amounts up to 40%. A method for production of magnetic PMMA cements (MPCs) with high reproducibility and dimensional accuracy was developed. The mechanical properties, in vitro bioactivity, cytotoxicity and heat generation of the resulted MPCswere evaluated.Compressive strength and four-point bending tests on MPCs were performed using the ISO 5833:2002 standard. The magnetic cements containing up to 30% MGC met the ISO 5833:2002 standard requirements.In vitro bioactivity was tested in a simulated body fluid (SBF). Apatite crystals started to form on the surface of MPCs after 2 weeks of immersion in SBF, showing the bioactive properties of these MPCs. Although cytotoxicity test results were found inconclusive, there was a decrease in the cell viability with addition of MGC in the bone cement. Preliminary induction heating tests showed that all MPC samples could be heated to a similar temperature range in 5 minutes using magnetic fields compatible with operating rooms in hospitals. The thermal, mechanical and biological properties of MPCs, analysed during this PhD thesis, showed that MPCs are promising biomaterials for the treatment of bone cancer using magnetic induction hyperthermia.