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.

Preparation of pH-sensitive chitosan/polyvinylpyrrolidone/α-Fe2O3 nanocomposite for drug delivery application: Emphasis on ameliorating restrictions.

Chitosan (CS)/polyvinylpyrrolidone (PVP)/hematite (α-Fe2O3) nanocomposites loaded with Doxorubicin (drug model) were synthesized via an oil-in-water emulsification method to develop a biocompatible and pH-sensitive drug nanocarrier for the first time. A hydrogel, including CS, PVP, and α-Fe2O3, was fabricated successfully with glutaraldehyde (GA) as the cross-linker. Incorporating α-Fe2O3 into CS/PVP hydrogel improved the pH-sensitivity and developed beneficial hydrogel. FTIR and XRD analysis illustrated physical interactions between polymer-polymer, polymer-drug, and crystalline behavior of prepared nanocomposite. These analyses also confirmed chemical bonding in nanocomposite's structure. The FE-SEM analysis showed successful impregnation of α-Fe2O3 into CS/PVP matrix and spherical structure. To clarify the size distribution and surface charge of the drug-loaded nanocomposite (CS/PVP/α-Fe2O3/Dox), DLS and zeta analyses were conducted. They showed the mean size of nanocomposites at about 247 nm. Drug-loaded CS/PVP/α-Fe2O3 nanocomposite and CS/PVP/Dox were studied for their release behavior and kinetics. Furthermore, the effect of α-Fe2O3 on release from CS/PVP/α-Fe2O3/Dox nanocomposite was investigated. That showed an increase in encapsulation of Doxorubicin and beneficial release behavior such as slow-release and retention effect. The release from this drug-loaded nanocomposite revealed excellent pH-sensitive and controlled release of the drug. Besides, the in vitro cytotoxicity and cell apoptosis were studied to recognize biological properties. These analyses revealed that drug-loaded nanocomposite caused high inhibition to MCF-7 cells in presence of α-Fe2O3 and proved the hematite's anti-cancer effect. By and large, this study confirmed CS/PVP/α-Fe2O3 nanocomposites as a potential candidate for the controlled pH-sensitive release of the drug.