Silver Nanoparticles Incorporated in pH-Sensitive Nanocomposite Hydrogels Based on Carboxymethyl Chitosan-Poly (Vinyl Alcohol) for Use in a Drug Delivery System

The CMCh-PVA/Ag nanocomposite hydrogels have been introduced a new technique to deliver drugs, which is dependent on pH. They were prepared successfully in situ by forming of Ag nanoparticles within swollen CMCh-PVA hydrogels. The resulting hydrogels were examined by running various experimental procedures such as FT-IR, XRD, EDX, SEM, and TGA. XRD and EDX patterns verified the formation of Ag nanoparticles in the hydrogel networks; moreover, the formation of Ag nanoparticles with size range from 21 to 81 nm within the hydrogel matrix was confirmed by SEM micrographs. It was shown that increased Ag+ concentration led to increased number of Ag 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 show that the prepared nanocomposite hydrogels outperformed the pure CMCh-PVA hydrogels in terms of swelling capacity. The antibacterial activity of the nanocomposite hydrogels was examined, and mechanisms involved in their synthesis were reported; the results showed an excellent antibacterial behavior of the nanocomposite hydrogel. To study the efficiency of this new category of nanocomposite hydrogels to be used as an in vitro drug release test to controlled drug delivery system. Also, for CMCh-PVA hydrogels-containing Ag nanoparticles sustained and controlled drug releases were observed that increased with increase in Ag nanoparticles content which can lead to prolong the release of the drug. Lay Summary The objective of this study is to prepare a new, improved drug release using pH-sensitive polymers of carboxymethyl chitosan-PVA with the weight ratios of 3:1, 1:1, and 1:3 containing AgNPs. In this study, to synthesize the new CMCh-PVA/Ag nanocomposite hydrogels efficiently, the Ag+ ions were reduced in the CMCh-PVA hydrogel medium in situ. The effect of the concentration of the Ag nanoparticles in gel content measurement, the swelling/deswelling ratio and drug release behavior and antibacterial activity for the Gram-negative E. coli and Gram-positive S. aureus bacteria was considered.