Synthesis and characterization of chitosan/polyvinylpyrrolidone coated nanoporous γ-Alumina as a pH-sensitive carrier for controlled release of quercetin.

pH-sensitive drug delivery systems based on amphiphilic copolymers constitute a promising strategy to overcome some challenges to cancer treatment. In the present study, quercetin-loaded chitosan/polyvinylpyrrolidone/γ-Alumina nanocomposite was fabricated through a double oil in water emulsification method for the first time. γ-Alumina was incorporated to improve the drug loading efficiency and release behavior of polyvinylpyrrolidone and chitosan copolymeric hydrogel. γ-Alumina nanoparticles were obtained by the sol-gel method with a nanoporous structure, high surface area, and hydroxyl-rich surface. Quercetin, a natural anticancer agent, was loaded into the nanocomposite as a drug model. XRD and FTIR analyses confirmed the crystalline properties and chemical bonding of the prepared nanocomposite. The size of drug-loaded nanocomposites was 141 nm with monodisperse particle distribution, having a spherical shape approved by DLS analysis and FE-SEM, respectively. Incorporating γ-Alumina nanoparticles improved the encapsulation efficiency up to 95%. Besides, swelling study and the quercetin release profile demonstrated that γ-Alumina ameliorated pH sensitivity of nanocomposite and a targeted controlled release was obtained. Various release kinetic models were applied to the experimental release data to study the mechanism of drug release. Through MTT assay and flow cytometry, the quercetin-loaded nanocomposite showed significant cytotoxicity on MCF-7 breast cancer cells. Also, the enhanced apoptotic cell death confirmed the anticancer activity of γ-Alumina. These results suggest that the chitosan/polyvinylpyrrolidone/γ-Alumina nanocomposite is a novel pH-sensitive drug delivery system for anticancer applications.