Sulfonated PVA microspheres for drug delivery and simulated body fluid interaction

We prepared sulfonated polyvinyl alcohol/polyvinyl acetate-poly(2-acrylamido-2-methylpropanesulfonate) microspheres (PVA/PVAc-PAMPS microspheres) by copolymerization of vinyl acetate (VAc) and 2-acrylamido-2-methylpropanesulfonate (AMPS), followed by saponification. The obtained size distribution was between 9 and 152 micrometers. An unconventional method as proton induced X-ray emission (PIXE) complemented by Fourier transform infrared spectroscopy (FTIR) was used to study the biodegradability of microspheres in simulated body fluid (SBF). A continuous loos of sulfonate groups during soaking up to 21 days was determined. Loading of PVA/PVAc-PAMPS microspheres with Doxorubicin resulted in a capacity of 5.9 ± 0.2 mg per gram of microspheres in 24 h, also resulted in an adsorption kinetics well described by the pseudo second order model. Desorption data fitted using the Ritger-Peppas equation showed an anomalous release mechanism.