Preparation and Characterization of Chitosan Microspheres Encapsulating Superparamagnetic Fe3O4 Nanoparticles

Chitosan microspheres (Chi-Fe microspheres) encapsulating superparamagnetic iron oxide nanoparticles (SPION, Fe₃O₄) were produced using a high voltage electrostatic field system. The surface morphology and size of these prepared Chi-Fe microspheres were examined using optical microscopy and scanning electron microscopy. The preliminarily results showed that the size of the Chi-Fe microspheres was at the range of 600 μm in diameter, however, the surface morphologies could be changed by treating with different ratios of crosslinking solution. The formulation with ratio of 17:3 (Na₅P₃O₁₀: NaOH) had a smoother surface and better mechanical strength. The amount of SPION encapsulated increased the size of Chi-Fe microspheres and the minimum amount of SPION to have significant magnetization result was 1.68mg (30%). The Chi-Fe microspheres could be attracted (or moved) under the magnetic field.