In vitro efficacy of antibiotic magnetic dextran microspheres complexes against Staphylococcus aureus and Pseudomonas aeruginosa strains

This paper describes the direct precipitation of magnetite on the surface of dextran as a method to improve the efficiency of this polymer in delivering antibiotics in active forms. FT-IR, SEM, XRD and in vitro biological assay were used to characterize the structure, composition, and the capacity of the magnetic polymeric microspheres to improve the antimicrobial activity of some antistaphylococcal and apntipseudomonal drugs. Our results demonstrated that the magnetic dextran microspheres could be used as macromolecular carriers for large-spectrum antibiotics, particularly for those with small, polar molecules belonging to penicillins, aminoglycosides, rifampicines and quinolones classes. The obtained results are suggesting that the size and the electric charge of the active drugs are influencing the specific interactions between the drug carrier and the active substance.