The potential use of cross-linked alginate/gelatin hydrogels containing silver nanoparticles for wound dressing applications

In this study, alginate/gelatin (Alg/Gel) hydrogels containing silver nanoparticles (AgNPs) cross-linked with 1.0, 2.5, and 5.0% w/v calcium chloride (CaCl2) were fabricated using solvent casting method. The morphology and mechanical properties of Alg/Gel hydrogels containing AgNPs were observed by scanning electron microscopy and universal testing machine. The mechanical performance demonstrated that the Alg/Gel hydrogels containing AgNPs cross-linked with CaCl2 showed improved mechanical properties with increasing CaCl2 concentration. The water swelling and weight loss behaviors of these hydrogels were investigated in an acetate buffer solution. Increasing concentration of CaCl2 from 1.0 to 5.0% w/v, the hydrogels manifested the lower swelling and weight loss behaviors. For in vitro AgNP release, the results showed that the released silver (Ag+) ions amount from the hydrogels cross-linked with 5% w/v CaCl2 was the highest followed by those of 1.0% and 2.5% w/v CaCl2, respectively. Moreover, these hydrogels showed the antibacterial activity against S. aureus, P. aeruginosa, and E. coli. Lastly, these hydrogels were non-toxic to both NHDF and NCTC clone 929 cells. Thus, these Alg/Gel hydrogels containing AgNPs had a potential for use in various wound dressing and biomedical fields.