Background  Superparamagnetic iron oxide nanoparticles (SPIONs) represent a simple yet effective system for delivering drugs to targeted tissue sites. The advantages of SPIONs as controlled drug‐delivery devices include a decrease in single‐dosage size, a continuous drug concentration, decreased systemic side effects, and SPIONs have been widely used in medicine for diagnostic imaging and therapeutic applications.

  Objective  To prepare dexamethasone loaded PLGA (poly lactic-co-glycolic acid) magnetic microsphere and observe its appearance, quality, biocompatibility and in vitro release and so on.

  Methods  The microspheres were prepared by emulsion-solvent evaporation method. The quality was assessed by calculating its shape, span, yield, drug loading, entrapment efficiency, in vitro release and magnetic responsiveness; and the biocompatibility was evaluated by haemocompatibility and histocompatibility test.

  Results  The span of the microspheres was (29.66±10.02) μm with a yield of (87.25±3.14)%. The drug loading and the entrapment efficiency were (30.33±2.01)% and (78.89±2.42)%, respectively. The in vitro release model was Q=4.084 4t^1/2+6.660 2 (R²=0.977), and no obvious sudden release in the process was observed. The cumulative release rate was 66.99% on the 14th day, with reliable magnetic responsiveness. There was no abnormality in biocompatibility.

  Conclusion  The self-made dexamethasone PLGA magnetic microspheres have good quality and biocompatibility.