pH-sensitive polyacrylic acid /Fe3O4@SiO2 hydrogel nanocomposite modified with agarose for controlled release of quercetin

Cancer has consistently been a significant global concern as the leading second cause of death. Improving the performance of chemical methods using a drug delivery system is an alternative approach to cancer treatment. In this study, the delivery of an anti-cancer drug, quercetin (QC), was investigated by placing it in a pH-sensitive hydrogel nanocomposite made of polyacrylic acid (PAA), agarose, and Fe3O4@SiO2 particles. Then, the drug release control was improved by the double emulsion method. Spherical nanoparticles with a smooth surface morphology were observed in the images obtained through field-emission scanning electron microscopy (FESEM), their average size was determined to be 193 nm using dynamic light scattering (DLS) method, and they exhibited a zeta potential of 38 mV. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses provided evidence of the interactions and chemical bonds in the hydrogel structure. The magnetic properties of the nanocarrier were studied by vibrating-sample magnetometry (VSM). The amount of drug loaded in the PAA-Agarose/Fe3O4@SiO2 increased to 86 %, while the encapsulation efficiency increased to 48 %. Drug release kinetics at physiological (7.4) and acidic (5.4) pH were best fitted with the Korsmeyer-Peppas model, indicating a non-Fickian diffusion mechanism. The U-87 MG glioma cell line was evaluated for toxicity through cytotoxicity assay (MTT) and flow cytometry. A higher percentage of apoptosis was found in PAA-Agarose/Fe3O4@SiO2-QC compared to the free QC system. The findings corroborate that the approach developed herein is highly effective for pH-responsive drug delivery in cancer treatment applications.