Pectin and mucin modified cellulose-based superabsorbent hydrogel for controlled curcumin release

Pectin (Pec) and mucin (Muc) were incorporated into a pure cellulose hydrogel network prepared in a urea/NaOH solvent system and cross-linked with epichlorohydrin to create cellulose-based superabsorbent hydrogels. Hydrogels were also tested for pH-responsive swelling capacity and in vitro drug release behavior. It was observed that swelling ratios increased several folds for the Pec/Muc-modified hydrogels compared to pure cellulose hydrogel and the maximum swelling ratio was 2781% at pH 10 for Pec-modified hydrogel. Besides, different drug release profiles were observed in different pH mediums, where a highly swollen and less eroded matrix showed a slower release due to a larger diffusion path. The incremented swelling ratio of modified hydrogels was attributed to numerous functional groups present on the backbone of the polymers, which aided in forming excessive hydrogen bonds with water. Structural characterization and possible interactions among cellulose and incorporated materials inside the hydrogels were confirmed by attenuated total reflection Fourier transform infrared spectroscopy, field emission scanning electron microscope, and simultaneous thermal analysis. Moreover, the mechanical properties of the Pec and Muc incorporated hydrogels were significantly improved. Owing to the tunable pH-sensitive water absorption, drug release behavior, and improved mechanical properties, Pec/Muc-modified cellulose hydrogels present a wide range of possibilities for further expansion in controlled drug delivery systems and other biomedical applications. Graphical abstract