Silver Release Diffusion Modeling and Biological Performance of Poly(Vinyl Alcohol)/Alginate Hydrogels with Embedded Silver Nanoparticles

Silver nanoparticles have been electrochemically embedded in poly(vinyl alcohol)/alginate hydrogels, producing composites with antibacterial activity and controlled silver release. UV–visible and FTIR spectroscopy confirmed the incorporation of silver nanoparticles and established bonds in composite hydrogels. The silver nanoparticle-loaded hydrogels exhibited strong antibacterial activity, achieving complete reduction of Staphylococcus aureus TL and Escherichia coli ATCC 25922 cells after only 1 h of exposure, while the MTT assay confirmed their biocompatibility, with cell viability above 80% for both L929 and MRC-5 cell lines. Silver release was measured in phosphate buffer at 37 °C using atomic absorption spectroscopy (AAS). Release kinetics was analyzed using our two-compartmental model with a general fractional derivative and compared with established approaches in diffusion modeling. The general fractional derivative (GFD) model provided the closest fit to the experimental silver release data, exhibiting the lowest fitting error values (R = 0.0014 for silver/PVA/0.5 wt% alginate and R = 0.0051 for silver/PVA/1.0 wt% alginate) and enabling the accurate determination of the silver diffusion coefficient over the entire release period. These findings demonstrate that silver/poly(vinyl alcohol)/alginate hydrogels combine biocompatibility, antibacterial efficacy, and predictable silver release, highlighting their potential as advanced wound dressing materials with controlled antimicrobial delivery.