Fe3O4-alginate nanocomposite hydrogel beads material: One-pot preparation, release kinetics and antibacterial activity.

Abstract In this work, a new and easy process was developed to fabricate a Fe3O4-alginate (Fe3O4NPs-ALG) hydrogel nanocomposite magnetic beads material. This preparation way consists in crosslinking sodium alginate solution in a mixed iron chloride solution containing FeCl3 and FeCl2. All characterization techniques confirmed the formation of small Fe3O4 nanoparticles with an average size of 9 nm in the alginate biopolymer matrix, in which iron atoms were linked to carbonyl acetyl groups through a bidentate bridging coordination. Furthermore, the magnetic nanocomposite beads have negatively charged surface. The obtained material was loaded with amoxicillin (AMOX) and tested as drug delivery system in the biolysis serum (NaCl 0.9% of pH 7) and in the simulated gastric medium (pH 2.1). The results showed that a cumulative release rate of 81.49% was obtained after three days in the biolysis serum, while this release rate was about 11.65% only, after four days, in the simulated gastric medium. The kinetic release data fulfilled Korsmeyer-Peppas model and the Hixson-Crowell, respectively. Antibacterial test on drug-loaded nanocomposite beads showed high activity against three of pathogenic bacteria strains.