pH-Sensitive Nanocomposite Hydrogels Based on Carboxymethyl Chitosan/Poly(vinyl alcohol)/ZnO Nanoparticle with Drug Delivery Properties

The CsMe/PVA/ZnO nanocomposite hydrogels have been introduced as a new object to deliver drugs, which is dependent on pH. They were prepared successfully in situ by forming of ZnO nanoparticles within swollen CsMe/PVA hydrogels. The resulting hydrogels were examined by running various experimental procedures such as FTIR, XRD, EDX and SEM. XRD and EDX patterns verified the formation of ZnO nanoparticles in the hydrogel networks; moreover, the formation of ZnO nanoparticles with size range from 34 to 88 nm within the hydrogel matrix was confirmed by SEM micrographs. It was shown that increased Zn²⁺ concentration led to increased number of Zn nanoparticles. The prepared nanocomposite hydrogels were studied in terms of the swelling behavior at the pH of 2.1 (simulated gastric fluid) and pH 7.4 (simulated intestinal fluid); the results showed that the prepared nanocomposite hydrogels outperformed the pure CsMe/PVA hydrogels in terms of swelling capacity. To study the efficiency of this new category of nanocomposite hydrogels drug release tests were conducted. For CsMe/PVA hydrogels containing ZnO nanoparticles sustained and controlled drug releases were observed that increased with increase in ZnO nanoparticles content which can lead to prolong the release of the drug.