Green pH- and magnetic-responsive hybrid hydrogels based on poly(methacrylic acid) and Eucalyptus wood nanocellulose for controlled release of ibuprofen

Abstract

pH- and magnetic-sensitive hybrid hydrogels based on poly(methacrylic acid) (PMAA), nanocellulose (NC), carboxymethyl cellulose (CMC) and magnetite particles (MN) were prepared as ibuprofen delivery system. NC was isolated from wood waste material and added to highly hydrophilic PMAA in order to improve the mechanical properties of PMAA and enable the encapsulation of poorly water-soluble ibuprofen. CMC was added in order to stabilize magnetite particles. The pH- and magnetic-sensitivity of the obtained hybrid hydrogels (originated from PMAA and MN, respectively) provided targeted delivery and controlled release of ibuprofen. Hybrid hydrogels were characterized by various technics: FTIR, SEM, XRD, VSM, the modified Faraday method, photon correlation spectroscopy and by using single compression tests. The swelling behavior of hybrid hydrogels and cumulative ibuprofen release were investigated depending on wt% of NC and MN in two media which were simulating pH environments in human stomach and intestines. The swelling degree of hybrid hydrogels and the percent of cumulative ibuprofen release decreased with the increase in wt% of NC. The same was found for increasing wt% of MN. Ibuprofen release kinetics was investigated with Korsmeyer–Peppas model. The obtained results showed that the prepared green dual responsive hybrid hydrogels were excellent candidates for the controlled release of ibuprofen, showing that the release kinetic can be easily tuned by changing only one hydrogel component.