Guar gum oleate-graft-poly(methacrylic acid) hydrogel as a colon-specific controlled drug delivery carrier.

A novel type of ethylene glycol dimethacrylate (EGDMA) cross-linked guar gum oleate-graft-poly(methacrylic acid) (GGO-g-PMAc) hydrogel was prepared as a pH-responsive controlled release carrier for colon-specific drug delivery. The structure of GGO-g-PMAc hydrogel was characterized by FT-IR, 1H NMR and X-ray diffraction (XRD) analysis. The swelling degree of the GGO-g-PMAc hydrogel at pH 7.4 was found to be higher than that at pH 1.2. The drug release studies performed in pH 7.4 and 1.2 buffer solutions at 37°C revealed that the rate and amount of drug released from the GGO-g-PMAc hydrogel at pH 7.4 were higher than that at pH 1.2. The MTT assay revealed that there is no noticeable cytotoxicity of GGO-g-PMAc hydrogel at the concentration range of 0-100μg/ml against the mouse mesenchymal stem cell line (C3H10T1/2). These results suggested that GGO-g-PMAc hydrogel can be a prospective pH-sensitive carrier for colon-targeted drug delivery.