Burn‐Safe Biodegradable Magnetocaloric Composites for Temperature‐Controlled Biomedical Applications

Abstract Magnetothermal stimulation is key in biomedical applications like tumor ablation, drug delivery, and regenerative therapies. A common method involves injecting magnetic particles that heat under an alternating magnetic field (AMF). However, uncontrolled heating can damage healthy tissues. Maintaining temperatures below 45 °C is critical. Using materials with a Curie temperature ( T _c ) near this limit offers a self‐regulating solution, as magnetization—and thus heating—drops sharply at T _c . This study explores Mn _0.65 Fe _1.30 P _0.65 Si _0.37 (MCM), a magnetocaloric material composed of non‐toxic elements and featuring a tunable T _c . It is engineered to exhibit a T _c of 43 °C, close to the safe physiological threshold. MCM particles are encapsulated in a wax matrix to form a composite that responds to AMF exposure. Heat generated by MCM particles triggers the wax phase transition, while the obtained T _c enables the composite to achieve self‐limiting thermal regulation under magnetic field exposure. Biocompatibility tests using human umbilical vein endothelial cells (HUVECs) show over 90% cell viability in direct and indirect contact. Stability tests in phosphate buffers at 37 °C confirm controlled degradation over 28 days. These results demonstrate that MCM is a promising, burn‐free magnetic material for safe, localized heating, supporting its use in self‐regulating, temperature‐responsive biomedical systems.