Novel sustainable and thermal-responsive composite hydrogel based on poly (vinyl alcohol)-glycerin-xanthan gum as a drug carrier for metronidazole

Due to temperature sensitivity, biocompatibility, biomedical applications and versatility a lot of interest has always been focused on the synthesis, characterization, and application of thermo-responsive hydrogels. In this study, a set of thermal responsive biocomposite hydrogels composed of poly (vinyl alcohol) (PVA) and Xanthan Gum (XG) biopolymers were fabricated by a low-cost and simple approach based on solution mixing method followed by double physical crosslinking with glycerol (Gly) and then freeze-thawing method. The obtained hydrogels have shown mechanical properties and chemical stability. SEM results demonstrated that the resultant hydrogels had asymmetric structures with interconnected non-uniform porous networks offering sufficient space for cell growth, attachment, proliferation, and drug or water molecule absorption and release. Drug-loaded hydrogels through the swelling diffusion method display good absorption and distribution of drug (N atoms) which were confirmed by EDX. The presence of all components in prepared hydrogels was approved by FT-IR and XRD analysis. The obtained samples also showed suitable mechanical and thermal stability. Moreover, UV–Vis spectroscopy was employed to assess the drug release profile of metronidazole from the hydrogels at various pH and temperatures, revealing a temperature-dependent and slow-release pattern of metronidazole over 10 h. Therefore, they are a potential candidate for controlled drug delivery applications. The antimicrobial properties of the hydrogels were investigated against Escherichia coli and Bacteroides fragilis. The results indicated they are only effective against Bacteroides fragilis without any growth inhibition against Escherichia coli, PVA-Gly-XG hydrogel is a promising candidate worthy of extensive exploration in specific anti-bacterial systems.