Magnetic polyvinyl alcohol microspheres with self-regulating temperature hyperthermia and CT/MR imaging for arterial embolization

Trans-catheter arterial embolization, as a minimally invasive therapy strategy, has become a choice for treating liver cancer. Development of embolic agents integrated with therapy and imagining functions is desired. Herein, magnetic polyvinyl alcohol (PVA) microspheres as embolic agents are prepared by emulsification method. The diameter of the magnetic PVA microspheres ranges from 10 to 110 μm, and the required size can be obtained by sieving. The temperature of magnetic PVA microspheres suspension could stabilize at 49 °C under the applied magnetic field, which indicates the microspheres have self-regulating temperature hyperthermia characteristic due to the application of magnetic nanoparticles with low Curie point. In addition, magnetic PVA microspheres possess obvious contrast effects on CT and T2-weighted imaging due to the existence of magnetic nanoparticles. Cytotoxicity assay indicates the survival rate of cells cultured with leach liquor of 30 mg/mL PVA/MNPs microspheres is 97.4%, which shows the magnetic microspheres have good cell biocompatibility. The developed magnetic microspheres have the potential to realize embolization, self-regulating temperature hyperthermia, and CT/MR imaging simultaneously in interventional therapy.