Preparation of magnetothermal Fe3O4/MgO/HA composite scaffolds for cancer hyperthermia by Vat Photopolymerization

Bone defects resulting from bone tumor resections are often complicated with residual cancer cells. To address the challenge, the magnetothermal porous structured bone scaffolds of hydroxyapatite-Fe₃O₄-MgO (HA-FM) were fabricated by Vat Photopolymerization (VPP). This study improved curing behavior by doping Mg(OH)₂ into Fe₃O₄ powder via the chemical deposition method. Mg(OH)₂ functioned as a pore-forming agent during the sintering process, decomposing into MgO to enhance biocompatibility. A two-step debinding method combined with a carbon powder embedding sintering process was used employed to resolve the conflict between the removal of photosensitive resin and the oxidation of Fe₃O₄. After sintering at 1200°C, the porosity of the composite ceramics reached 69 % and a compressive strength of 2.28 MPa. In vitro mineralization tests showed that doping with Fe₃O₄ and Mg(OH)₂ could promote the scaffolds’ degradation in simulated body fluid (SBF), beneficial to mineralization process. In vitro cell proliferation and adhesion experiments showed that ceramic samples were not cytotoxic and could promote osteogenic differentiation. The composite scaffolds exhibited magnetothermal properties, achieving a temperature increase of 8.2°C in the alternating magnetic field of 92 G and 100 kHz, indicating potential for cancer treatment.