The current workdeveloped a novel kind of pH-sensitive nanocarrier by combining a hydrogel nanocomposite composed of polyethylene glycol (PEG), polyvinyl alcohol (PVA), and zinc oxide nanoparticles (ZnO NPs) with an extensive surface area.To provide quality control, the nanocarriers were synthesizedusing the water/oil/water (W/O/W) emulsifying method to deliver quercetin (QC). Considering the compelling possibility of QCas a cancer treatment, it is imperative to overcome the challenges associated with its rapid release and poor solubility. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) were used to assess the nanocarrier’s crystalline structure and component interactions.The scanning electron microscopy (SEM) illustrationsconfirmed the surface uniformity of the nanocarrier and its spherical morphology. Dynamic light scattering (DLS) and zeta potential provide information on the nanocarrier’saveragesize, surface charge, and stability variations.High QC loading and encapsulationefficiencies were obtained, which were further improved uponaddition of ZnO NPs.The release kinetics of drug-loaded PEG/PVA/ZnO nanocomposites were investigated at pH=5.4 and pH=7.4, revealing an excellent controlledpH-sensitive release profile.The in vitro cytotoxicity of the nanocomposites was evaluated by MTT assay.As a result, a diminution in the total number of viableMCF-7 breast cancer cells when subjected to PEG/PVA/ZnO nanocomposites, compared with PEG/PVAsamples and the control groupsample, suggests that the addition of ZnO NPs has improved the cytotoxic activity of the nanocomposite.Hence, applyingPEG/PVA hydrogel encapsulated with ZnO NPs demonstrates significant promise inpH-sensitivecontrolled drug release.