In situ synthesis of Fe3O4/cellulose microspheres with magnetic-induced protein delivery

Regenerated cellulose microspheres (RCS) were successfully prepared by using the sol-gel transition (SGT) method from cellulose drops in 7 wt% NaOH/12 wt% urea aqueous solution precooled to -12 degrees C. Subsequently, novel magnetic Fe3O4/cellulose microspheres (MRCS) were fabricated by in situ synthesis of Fe3O4 nanoparticles into the cellulose pores of RCS, which were used as the solid template microreactor. Their structure and morphology were analysed using optical photomicrographs, scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The results indicated that the spherical magnetic Fe3O4 nanoparticles were dispersed uniformly and immobilized in the cellulose matrix, and the structure and nature of Fe3O4 were conserved perfectly. The magnetometric measurements revealed that the MRCS exhibited sensitive magnetic-induced delivery, and had extremely small hysteresis loop and low coercivity. Moreover, MRCS displayed excellent adsorption and controlled release capabilities on bovine serum albumin (BSA). The Fe3O4 nanoparticles in the cellulose microspheres play an important role in both the creation of the magnetic-induced transference and the improvement of the targeting protein delivery and release. It will be important for applications in the biomaterials field.