A non-toxic synergistic antibacterial platform based on green silver nanoparticles deposited on hydroxyapatite/graphene oxide composites

A composite containing hydroxyapatite, graphene oxide and silver nanoparticles was obtained by performing a microwave-assisted hydrothermal method, a modified Hummer's synthesis, and advantageously, by using dietary quercetin for silver nanoparticles formation and deposition. The pure constituents and composites were char-acterized by complementary physicochemical techniques, and evaluated in human keratinocytes and bacteria. In eukaryotic cells, it was found a dose-dependent toxic response that mainly depends on the presence of graphene oxide, and a superior cytocompatibility was observed for the samples containing hydroxyapatite. The ternary system showed a half maximal inhibitory concentration of about 116.8 & mu;g/mL, ranged in a safety threshold. In comparison with silver nanoparticles alone, this ternary composite increased in 43% and 38% the inhibition zone for S. aureus and E. coli, respectively. Its minimum inhibitory concentration was found, respectively, close to 6.5 and 52.1 & mu;g/mL, resulting in a fractional inhibitory concentration index < 0.5. Thus, this synergistic system can potentially be applied as a bactericidal for tissue replacement and surface coating.

Automated summary

A composite material containing hydroxyapatite, graphene oxide and silver nanoparticles was synthesized using a microwave-assisted hydrothermal method. The addition of dietary quercetin was utilized for the formation and deposition of silver nanoparticles. The composite exhibited cytotoxicity in human keratinocytes dependent on the presence of graphene oxide, while samples containing hydroxyapatite showed superior cytocompatibility. The ternary system displayed increased inhibition zone against S. aureus and E. coli compared to silver nanoparticles alone, making it a potential bactericidal material for tissue replacement and surface coating.