Preparation of monodisperse biodegradable magnetic microspheres using a T-shaped microchannel reactor

Monodisperse magnetic microspheres with biodegradability and biocompatibility were successfully prepared using a T-shaped microchannel reactor instead of the traditional three-necked flask equipped with the mechanical stirrer. Solvothermal was adopted to produce hydrophilic ferriferrous oxide (Fe3O4) nanoparticles with high magnetic responsiveness, which was subsequently emulsified with a dichloromethane solution of polylactic acid (PLA) in the presence of a gelatin stabilizer. This water-in-oil (W/O) emulsion and an additional aqueous phase, namely an aqueous polyvinyl alcohol (PVA) solution, were injected into the T-shaped microchannel reactor and converged at the joint to yield a W/O/W composite emulsion. Evaporation of the solvent in the microchannel gave rise to the target magnetic microspheres. The results show that the magnetic microspheres have a uniform particle size and good magnetic responsiveness, indicating their potential use in targeted drug delivery for cancer treatment and thermotherapy.