Gelatin-based hydrogels and ferrogels as smart drug delivery systems: synthesis, characterization and drug release kinetics

The objective of this study was to develop biodegradable, environmentally friendly, economical and smart gelatin-based hydrogels and ferrogels as controlled drug delivery systems. Cross-linking is an important treatment for controlling the drug release from hydrogels, as well as enhancing the thermal and mechanical stability of hydrogels. In this study, gelatin-based hydrogels and ferrogels were synthesized at different cross-linker concentrations, ranging from 4 to 16 wt% to allow for different mesh and pore sizes in the gelatin matrix. The gels were characterized by thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The swelling properties and in-vitro release of tetracycline as a model drug from the hydrogels and ferrogels cross-linked with different ratios by the diffusion mechanism were tested in solutions of pH 6.5 and 7.4 at 37 & DEG;C, which mimics environments similar to those of the mouth and intestines. The results showed that the swelling and drug release properties of all the gelatin hydrogels and ferrogels significantly depended on the cross-link level because of the effect of the cross-linking mechanism on reducing the number of free carboxyl and free amino groups of gelatin matrix. In addition, it was observed that the presence of magnetic nanoparticles in the gelatin matrix has an effect of decreasing the swelling and drug release percent of the gelatin-based hydrogels.