In Vitro Toxicity Evaluation of Hydrogel-Carbon Nanotubes Composites on Intestinal Cells

Composite materials based on carbon nanotubes (CNT) and polymeric hydrogels have become the subject matter of major interest for use as carriers in drug delivery research. The aim of this study was to evaluate the in vitro cytotoxicity of the hydrogel-carbon nanotube-chitosan (hydrogel-CNT-CH) composites on intestinal cells. Oxidized CNT were wrapped with chitosan (CH), Fourier transform infrared (FT-IR) analysis suggest that oxidized CNT interact with CH. Transmission electron microscopy (TEM) images show a CH layer lying around CNT. Chitosan wrapped CNT were incorporated to poly (acrylamide-co-acrylic acid) hydrogels. Swelling behavior in buffers at different pH were evaluated and revealed a significantly lower swelling when it is exposed to a acid buffer solution (pH 2.2). Mechanical properties were evaluated by measurements of elasticity and the material with CNT showed better mechanical properties. The incorporation and liberation of Egg Yolk Immunoglobulin from hydrogel-CNT-CH were also assessed and it revealed an improved performance. To evaluate the effect of these nanocomposites on cellular redox balance, intestinal cells were exposed to hydrogel-CNT-CH composites and antioxidant enzymes were assessed. Cytotoxicity and apoptosis were also evaluated. Hydrogel-CNT-CH composites induce no oxidative stress and there were no evidence of cytotoxicity or cell death. These preliminary findings suggest that hydrogel-CNT-CH composites show improved properties and good biocompatibility in vitro making these biomaterials promising systems for drug delivery purposes. (c) 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41370.