Fabrication and characterization of triple-responsive composite hydrogel for targeted and controlled drug delivery system

In this study, to prepare a new magnetic composite hydrogel (Mag-H) based on gelatin/bacterial cellulose (BC), we synthesized gelatin-coated magnetic nanoparticles and then incorporated into the gelatin/BC matrices, followed by chemical crosslinking with glutaraldehyde. The physicochemical properties of Mag-H were evaluated by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), texture analyzer, swelling test, and in vitro drug release behavior using methylene blue (MB) as a model drug. The FTIR spectra showed that glutaraldehyde crosslinked with gelatin. To improve the thermal and mechanical properties of gelatin hydrogel (Gel-H), the BC and magnetic nanoparticles were incorporated into the gelatin network. Due to the superparamagnetism of magnetic nanoparticles, Mag-H possessed a powerful magnetic property for achieving a magnetic targeting. Mag-H had a maximum swelling ratio of 1085±12% in phosphate buffer saline (pH1.2) at 37°C, meanwhile its maximum drug release of 80.77±0.33% was observed at the same condition with an external magnetic field application. Interestingly, Mag-H showed temperature-, pH-, and magnetic field-responsive properties, which would be a promising candidate for targeted and controlled drug delivery system.