Green tea extract mediated biogenic synthesis of silver nanoparticles: Characterization, cytotoxicity evaluation and antibacterial activity

•Silver nanoparticles were biosynthesized by green tea extracts.•Biocompatibility of nanoparticles was increased with polyethylene glycol (PEG).•Pure silver nanoparticles coated with polyphenols were obtained.•The nanoparticles did not cause significant toxicity to human keratinocyte (HaCaT) cells.•Antimicrobial efficacy was demonstrated against several human pathogenic bacteria.