Modified chitosan encapsulated core-shell Ag Nps for superior antimicrobial and anticancer activity

This investigation reports a one pot synthesis of silver nanoparticles (Ag Nps) using aqueous solution of chitosan-graft-poly(acrylamide) (Cts-g-PAAm) as a reducing agent and polyethylene glycol (PEG) as a stabilizing agent. The as synthesized Ag Nps was characterized by ultra violet-visible (UV-vis), Fourier transform infrared (FTIR) and X-ray diffraction (XRD) analysis. Field emission scanning electron microscopy (FESEM), dynamic light scattering (DLS) and transmission electron microscopy (TEM) showed that Ag Nps, which were stable upto more than 60 days, were spherical in shape and the particle size was in the range of 5-50 nm. Atomic force microscopy (AFM) image also supported the above obtained result. The prepared Ag Nps exhibited strong antimicrobial activity against different gram positive bacteria (Alkaliphilus, Bascillus substillis, Lysinibascillus) and gram negative bacteria (Enterobacter aerogenus, Vivbrio vulnificus and Escherichia coli) and haemolytic assay revealed its blood compatible nature. The synthesized Ag Nps showed significant cytotoxicity over human cervical HeLa cancer cells and it was found that the inhibitory concentration for 50% cell death (IC50) was 8 μg/ml.