Novel potentially biocompatible nanoporous hydrogel based on poly ((2-dimethylaminoethyl) methacrylate) grafted onto salep: synthesis, swelling behavior and drug release study

A novel potentially biocompatible nanoporous hydrogel was synthesized via crosslinking graft copolymerization of (2-dimethylaminoethyl) methacrylate (DMA) monomer onto salep backbones. Methylenebisacrylamide (MBA) and ammonium persulfate (APS) were applied as water-soluble crosslinker and initiator, respectively. To investigate the structure of the obtained hydrogel, fourier transforms infrared spectroscopy (FT-IR), thermo-gravimetric analysis (TGA) and scanning electron microscopy (SEM) were used. Swelling behavior of the obtained hydrogel at different temperatures and pH media was investigated and it was found that the synthesized hydrogel has a high sensitivity to pH. The swelling first increased and then decreased with increasing pH from 2 to 12 at 37 °C and the maximum water absorbency was observed at pH = 8. Swelling reversibility of the hydrogel at pH 2.0 and 8.0 was examined to show the pH sensitivity and smartness of hydrogel. Lastly, the potential use of this hydrogel for the loading and releasing of tetracycline hydrochloride (TH) as a model drug was examined. The results showed that 95 % of TH was released at pH 8 after 4 h at 37 °C which were best fitted with Korsmeyer kinetic model.