pH sensitive halloysite-sodium hyaluronate/poly(hydroxyethyl methacrylate) nanocomposites for colon cancer drug delivery

Abstract A safe and efficient halloysite-nanocomposite hydrogel for colon cancer drug delivery was synthesized using biocompatible and biodegradable materials composed of sodium hyaluronate with poly(hydroxyethyl methacrylate). Fourier-transform infra-red spectroscopy, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy were performed to confirm the formation, crystallinity, thermal and morphological properties of the nanocomposite hydrogel. The hydrogels exhibited good swelling properties in a pH sensitive manner. 5-Fluorouracil (5-FU), an anticancer drug, was encapsulated successfully into these hydrogels as well as inside the halloysite nanotubes through equilibrium swelling followed by pulling and breaking the vacuum. Transmission electron microscopy showed that 5-FU was also encapsulated in the halloysite nanotubes. In vitro release experiments were performed at 37 °C in stimulated gastric fluid (pH 1.2) for 2 h followed by stimulated intestinal medium (pH 7.4). It was found that the release of 5-FU from nanocomposite hydrogels followed pH-dependent controlled release as compared to that of conventional hydrogels. From the in vitro release studies it was found that the nanocomposite hydrogels are more efficient for colon cancer drug delivery.