We report the synthesis of sodium alginate-polyvinyl alcohol-g-acrylamide (NaAlg-PVA-g-AAm) nanocomposite hydrogels modified with silver nanoparticles (AgNPs) as an antibacterial agent. In this work, we used NaAlg isolated directly from brown algae and studied the effects of the NaAlg weight ratio and silver-ion concentration on the network matrix in the hydrogels via in situ polymerization. Successfully synthesized nanocomposites were characterized using Fourier transform infrared (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and atomic absorption spectrometry (AAS). The best results were achieved with an average AgNPs size of approximately 20 nm allowing the AgNPs to be absorbed in the nanocomposite hydrogel matrix. Nanocomposite hydrogels displayed good antibacterial activity against Escherichia coli and Staphylococcus aureus. The minimum inhibitory concentrations (MICs) of silver nitrate (AgNO3) for E. coli and S. aureus were 46.251 and 75.220 ppm, respectively. Conversely, the minimum bactericidal concentrations (MBCs) of AgNO3 for these bacteria were 185.004 and 300.880 ppm, respectively. The MBC/MIC ratio of the AgNO3 modified nanocomposite hydrogels was four for both bacteria. The results illustrated that the nanocomposite hydrogels had good antibacterial activity against Gram-positive and Gram-negative bacteria and can be suitable for applications in wound treatments.
Key words: AgNPs, antibacterial, hydrogel, nanocomposite, sodium alginate
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