INFLUENCE OF THE ADDITION OF MALTODEXTRIN AND β-CYCLODEXTRIN DURING THE BIOSYNTHESIS OF SILVER NANOPARTICLES AND ITS ANTIBACTERIAL ACTIVITY

QUINTEROS MA ; DALMASSO PR; AIASSA V; ZOPPI A; LONGHI MR; PAEZ PL

Córdoba

Congreso; XI Congreso Argentino de Microbiología General; 2015

At present, the composition and morphology associated to the layer of stabilization around the silver nanoparticles is of great interest to understand its stability. The dextrins have the ability to form complexes with the majority of the drugs, improving its solubility properties and stability to the light and heat. That is why the dextrins have a great potential to be used in thepharmaceutical industry. In the present study, we analyze the influence of added β-cyclodextrin (BCD) and maltodextrin (MD) to the medium of biosynthesis of silver nanoparticles, in addition to observing the changes on the stability, polydispersity and antimicrobial activity. MD is a polysaccharide encapsulation with high activity and BCD is a ciclycal member of MD family. The silver nanoparticles (AgNps) were biosynthesized from the reduction of silver ions by the supernatant of cells of Pseudomonas aeruginosa. At supernatant of P. aeruginosa, 15 mL of silver nitrate 10 mM and different concentrations of MD and BCD was added. The biosynthesized nanoparticles were characterized by UV?Vis spectroscopy, Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS) and Infrared Radiation (IR). The standard macrodilution method was used to evaluate the antibacterial activity of the AgNps biosynthesized. The technique of UV-vis showed the appearance of a surface plasmon peak around 400 nm indicating the formation of pseudo-spherical nanoparticles. An increase in the intensity of the absorption maximum indicated the formation of complexes with the dextrins. This was corroborated by the images obtained by TEM and IR,which confirmed the interaction of AgNps with dextrins due to the presence of the corresponding functional groups. The AgNps were exposed to the light and it was observed that those AgNps with a dextrins layer suffered an oxidation less than those without dextrins. Results from the DLS showed no major differences between the different types of nanoparticles. An average diameter between 100-120 nm and a Z potential of -30 was obtained which is correlated with a high stability. It showed that antibacterial activity of all AgNps biosynthesized with dextrins against the following reference strains Staphylococcus aureus29213, Escherichia coli 25922 and P. aeruginosa 27853 not change respect to the AgNPs alone. Faced with the growing demand for sustainable and environmentally friendly protocols, and the use of biodegradable and non-toxic precursors toprepare nanomaterials, we demonstrate the potential benefits to be gained by improving unfavorable physicochemical properties by the AgNps using dextrins as stabilizing agents.