Preparation and properties of magnetic polymer microspheres

Magnetic particles are widely used in medical diagnosis and treatment owing to their ever-increasing magnetic targeting ability and superparamagnetism. However, small particle size and low magnetic saturation (MS) are disadvantageous for targeted delivery of magnetic particles. In this study, Fe3O4@polyvinyl alcohol (PVA) microspheres were prepared by an on-chip droplet microfluidic technology on a polydimethylsiloxane microchip. The morphology and elemental analysis test results demonstrate that Fe3O4@PVA microspheres have a uniform particle size and even distribution of Fe3O4 nanoparticles on microspheres. The MS reaches 15.43 emu·g−1 when the concentration of Fe3O4 is 33.3%, which linearly increases with an increase in the content of Fe3O4 in the microspheres. The microscopic observation results of magnetic motion further prove that Fe3O4@PVA microspheres maintain good superparamagnetism and drivability. This preparation process is simple, fast, and accurate. Fe3O4@PVA microspheres show many potential applications in medical diagnosis and treatment.