Improving quercetin anticancer activity through a novel polyvinylpyrrolidone/polyvinyl alcohol/TiO2 nanocomposite

Abstract

A hydrogel nanocomposite comprising polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), and titanium oxide (TiO2) was prepared and encapsulated in a double emulsion as a pH-triggered delivery vehicle for quercetin (QC), an antitumor drug. Dynamic light scattering (DLS) was used to estimate the size and confirm the stability of QC-loaded nanoparticles. The interactions between the nanocomposite components, its crystalline structure and the morphology of the nanoparticles were characterized through Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM), respectively. Drug loading and encapsulation efficiency significantly improved after incorporation of TiO2, which corroborates the beneficial effect of this component. In vitro release experiments indicated the pH-responsivity of the nanocarrier, with higher amount of QC released in an acidic medium than at neutral pH. Due to the presence of a double emulsion, the release pattern was sustained and gradual in both environments. Cellular experiments including MTT assay and flow cytometry were conducted using U87 cell line to compare the anticancer activity of free QC and QCloaded nanoparticles. MTT assay was also performed on a noncancerous cell line (L929) to assess potential side effects of the drug release system. The results obtained herein confirm the suitability of the developed nanocarrier as an efficient drug delivery vehicle for tumor therapy.