Novel carboxymethyl cellulose/polyvinyl pyrrolidone hydrogel incorporating graphitic carbon nitride for quercetin delivery

Abstract

Herein, quercetin (QC) as a model anticancer drug was encapsulated in a carboxymethyl cellulose/polyvinyl pyrrolidone/graphitic carbon nitride (g-C3N4) nanocomposite synthesized via dual oil-in-water emulsification method. The nanocomposite hydrogel showed a high surface area, nano-porous structure and a hydroxylated surface. g-C3N4 enhanced the drug loading efficiency up to 95 %. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) analyses provided information about the crystalline structure of the nanocarrier and the interactions between its components, respectively. Field-emission scanning electron microscopy (FESEM) showed its spherical shape, with a mean particle size of 160 nm. Dynamic light scattering (DLS) revealed a monomodal and narrow particle distribution, with a PDI value of 0.12. Further, the average zeta potential was −38.7 mV, indicative of its high colloidal stability. The release kinetics of the drug-loaded nanocomposite was investigated at pH = 5.4 and 7.4, and the results showed a controlled and pH-sensitive release, with 97 % and 54 % QC released after 96 h, respectively. The mechanism of drug release was investigated via fitting the experimental release data to different kinetic models, and the best fitting were obtained for Korsmeyer–Peppas and Baker at pH 7.4 and 5.4, respectively. Significant cytotoxicity of the Qc-loaded nanocomposite on breast cancer model cells, MCF-7, was corroborated by flow cytometry and MTT assays. In addition, improved apoptotic cell death was attained due to the presence of g-C3N4 nanoparticles. Results support the high potential of the developed nanocomposite as a novel pH-responsive drug delivery system for cancer therapy.