Gamma alumina coated-PAA/PVP hydrogel as promising quercetin nanocarrier: Physiochemical characterization and toxicity activity

A novel polyacrylic acid (PAA)-based hydrogel coated with ?-alumina modified with polyvinyl pyrrolidone (PVP) was synthesized for the delivery of quercetin (QC) anticancer drug to MCF-7 cells. The addition of Al2O3 to the PVP-modified PAA hydrogel increased pH-sensitivity, and the use of Span 80 surfactant led to a nano niosomal emulsion that increased the stability and retention of QC. Likewise, paraffin oil was added to minimize the size of the microemulsions via double emulsion method and to protect them, preserving their quasi-spherical shape. The physical interactions between the components, the crystalline structure of the microemulsions and their morphology were analyzed through Fourier transform-infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM), respectively. Besides, the size distribution and surface charge of the drug-loaded microemulsions were characterized using dynamic light scattering (DLS) and zeta potential tests. Drug loading and entrapment efficiencies significantly improved with the double emulsion method, and were significantly higher than other QC delivery systems reported in the literature. QC release from ?-alumina-PAA/PVP microemulsion was investigated in PBS media at both physiological and tumor pHs. In vitro cytotoxicity and cell death were also analyzed using MTT and flow cytometry tests, respectively. Overall, results support that the developed ?-alumina-PAA/PVP nanoemulsion is a very promising and versatile candidate for pH-sensitive drug-controlled release, and could be used for oral, nasal, ocular and parenteral delivery.