Formulation and evaluation of silver nanoparticles as antibacterial and antifungal agents with a minimal cytotoxic effect

Preparation of non-biodegradable nonoparticles is a fast growing field,which is vital in both nanomedicine and nanotechnology applications.In this investigation, our attention will be focused on the preparationand evaluation of colloidal silver nanoparticles as antibacterial andantifungal agents. The colloidal silver nanoparticles have beenprepared employing standard chemical reduction methods. Thecolloidal silver nanoparticles were characterized using transmissionelectron microscopy TEM, zeta potential, photo correlationspectroscopy PCS, and in vitro release kinetics. The particles thusobtained were spherical in shape and having an average particles sizeof 5-20 nm , zeta potentials of -25.5 to -38.3 mV, and the releasekinetics was following zero order kinetics with r2>0.96. Thedissolution data indicates that the release of the silver nanoparticles isinversely correlated with the size of the nanoparticles i.e. the releaseincreased with smaller particles. The results suggest that the Ag NPswould be stable in the pharmaceutical preparations and will be easilyto the infection site. The colloidal silver nanoparticles were found tobe very efficient antibacterial agents for different types of bacteria.The bacteria studied were namely: E. coli, S. coccus, Salmonellae, andP. aeruginosa. The associated antifungal effects were also investigatedfor Aspergillus and Pencillium. . Cytotoxicity of the nanoparticle wasstudied using human fibroblast cell line. It was concluded thatcytotoxicity is concentrations dependant. The results provided strongevidence that could warrant the consideration of silver nanoparticles asantibacterial and antifungal agent that could circumvent the side andpassive effects of the conventional antibiotics.Keywords: Silver nanoparticles, antibacterial, antifungal, cytotoxicity, micro-plate assay, release kinetics