Preparation of magnetic poly(vinyl alcohol) microspheres via inverse miniemulsion technique

Polyvinyl alcohol (PVA) micro- and nanospheres provide new options for drug delivery due to their biocompatibility, biodegradability and their tunable drug loading and release properties. PVA nanodroplets were fabricated by inverse miniemulsion process and then PVA microspheres were obtained by using glutaraldehyde (GA) as a cross-linking agent. Magnetic nanoparticles were in situ formed on the surfaces of PVA microspheres based on the classical coprecipitation procedure to fabricate magnetic PVA microspheres. The microspheres were characterized by FTIR, X-ray diffraction (XRD), transmission electron microscopy (TEM), light scattering equipment, and vibrating-sample magnetometry (VSM), respectively. The experimental results clearly show that PVA droplets were solidified after the cross-linking reactions to form PVA microspheres. The magnetic PVA microspheres are about 80-200 nm with magnetic particle of about 18 nm on the surfaces. The biocompatible and biodegradable nature of PVA indicates that this system seems to be a very promising vehicle for hydrophilic drug delivery. (C) 2012 Elsevier B.V. All rights reserved.