Curcumin encapsulated pH sensitive gelatin based interpenetrating polymeric network nanogels for anti cancer drug delivery

Interpenetrating polymeric network nanogels (IPN-NGs) composed of natural gelatin biological protein macromolecules and poly(acrylamidoglycolic acid) were produced by simple free radical emulsion polymerization. The developed IPN-NGs were characterized by Fourier-transform infra-red spectroscopy to confirm the formation of NGs. The hydrophobic curcumin drug was loaded successfully into these NGs using an in-situ method. The curcumin-encapsulated NGs were well dispersed in aqueous solutions and showed good bioavailability. Curcumin was dispersed molecularly in the IPN-NGs, which was confirmed by differential scanning calorimetry and X-ray diffraction. The NGs exhibited pH sensitive properties according to dynamic light scattering and the zeta size potentials. Transmission electron microscopy revealed the NGs to be spherical, approximately 100 nm in size. The encapsulation efficiency of these IPNNGs drug formulations ranged from 42 to 48%. In addition, the release of curcumin from the NGs was examined in phosphate buffer medium. The cytotoxicity of the IPN-NGs was studied using in vitro cultures of fibroblasts and a colorectal cancer cell line. The results suggest that the newly developed pH sensitive gelatin-poly(acrylamidoglycolic acid)-curcumin NGs can be applied for colorectal cancer drug delivery applications. (C) 2014 Elsevier B.V. All rights reserved.