Hemicellulose-based pH-sensitive and biodegradable hydrogel for controlled drug delivery.

Hydrogels based on hemicellulose of wheat straw were prepared as a novel carrier for controlled drug delivery. The chemical structure and morphology of the hydrogels were characterised using FT-IR and SEM, respectively. The swelling ratios of the hydrogels were determined, and the results showed that the hydrogels were pH-responsive. The swelling kinetics of the hydrogels followed a Fickian diffusion process in media with a pH of 1.5, and water uptake was controlled collaboratively by hydrogel relaxation and water diffusion in media with pH values of 7.4 and 10.0. The degradation test of the hydrogels was conducted under simulated physiological conditions, and both hemicellulose content and the crosslinking density of the hydrogels were major factors that affected the biodegradability of the hemicellulose-based hydrogels. A comparison of the in vitro release of acetylsalicylic acid and theophylline indicated that the drug release was controlled both by the hydrogel and by the intrinsic character of the drug. According to the results presented here, hemicellulose-based hydrogels can be used in biomedical fields, especially for controlled drug release.