The Influence of Silver Nanoparticle Sizes on Antibacterial Activity, Cytotoxicity and Genotoxicity of Alginate Hydrogel Beads Containing Silver Nanoparticles

Abstract

Sizes of silver nanoparticles (AgNPs) have been shown to affect the biological activity of AgNPs. Hydrogel beads loaded with AgNPs have been extensively employed for biomedical applications. However, the influence of AgNPs sizes on biological activity of AgNP-loaded hydrogel beads has not much studied. Our objectives were to investigate the effect of AgNP sizes on the antibacterial activity, the cyto- and genotoxicity of AgNPs/alginate hydrogel beads. AgNPs of different sizes (⁓10 nm for S-AgNPs, and ⁓50 nm for L-AgNPs) were incorporated into alginate hydrogel beads during the preparation. The results showed that, S-AgNPs/alginate hydrogel beads (⁓89% inhibition) at AgNP concentration of 10 µg/ml tended to inhibit the growth of E. coli greater than L-AgNPs/alginate hydrogel beads (⁓49% inhibition) at the same dose. Moreover, at this effective antibacterial concentration (10 µg/ml), S-AgNPs/alginate hydrogel beads exhibited weak cytotoxic effect to HaCaT cells whereas L-AgNPs/alginate hydrogel beads showed non-cytotoxicity to this cell line. Furthermore, treatment of HaCaT cells with 10 µg/ml of S-AgNPs/ or L-AgNPs/alginate hydrogel beads did not result in a significant change in %DNA in tail when compared to untreated cells. Therefore, these AgNPs/alginate hydrogel beads, especially with smaller sized AgNPs, can be used as an antibacterial biomaterial with low cytotoxicity and genotoxicity to human cells.