Studies on the antimicrobial activity of Silver Nanoparticles as additive for several kind of materials

Studies on the antimicrobial activity of Silver Nanoparticles as additive for several kind of materials Rossana, Galassi;a Anna Teresa, Ramadori;a § Alfredo, Burini;a Daniela, Micozzi;b Stefania, Pucciarelli.b a Scuola di Scienze e Tecnologie, Divisione di Chimica, Università di Camerino, Via Sant’Agostino, 1, Camerino, I-62032, Italy. b Scuola di Bioscienze e Medicina Veterinaria, Polo di Bioscienze, Università di Camerino, Via Gentile III da Varano, Camerino, I-62032, Italy. § fellow granted by project T.R.A.S.P.A.R.E.N.T.E. DGR 1464 del 7/11/2011, Regione Marche. Silver nanoparticles (AgNPs) have attracted extensive research interest due to their attractive optical, electronic properties and excellent antimicrobial activities. AgNPs exhibit strong cytotoxicity towards a broad range of microorganisms and are widely used as an antibacterial agents.1 The advantage of AgNPs compared to bulk metal or salts is the slow and regulated release of silver from nanoparticles, thereby causing long lasting protection against bacteria. The antimicrobial activity of AgNPs is comparatively better than most prominent antibiotics used worldwide.2 Numerous methods have been developed for the preparation of AgNPs. The most common method is the chemical reduction of silver salt by a reducing agent in the presence of a stabilizing agent. In this work AgNPs have been prepared by reducing silver cations with NaBH4 and using as stabilizer sodium citrate, PVP (polivinylpirrolidone) or polysaccharides. AgNPs so obtained were characterized as average 10 nm particles by DLS and UV-vis spectroscopy. This work has the aim to verify the biocide action of silver nanoparticles mainly in plasters but also in other substrates occurring in a civil environment to reduce exposure to risk of infection by people with weak immune system. The study was focused to develop a method of study for each kind of material both in the AgNPs dispersion’s method and on the antimicrobial activity of the resulting substrate treated with AgNps. The antimicrobial activity has been led on Escherichia coli cells cultured in Luria Broth.3 The minimum concentration needed to have effects has been determined in each case. Moreover a comparative study of the inhibitory effect of AgNPs and silver salts such as AgNO3 and AgCF3SO3 on the regards of DHFR (DeHydroFolateReductase) from E. Coli has been performed. 1) Xihui Zhao; Yanzhi Xia; Qun Li; Xiaomei Ma Fengyu, Quan Cunzhen Geng, Zhenyu Han. Colloids and Surfaces A: Physicochem. Eng. Aspects 444, 2014, 180-188. doi.org/10.1016/j.colsurfa.2013.12.008 2) R. Roy, M. R. Hoover, A. S. Bhalla, T. Slawecki, S. Dey, W. Cao, J. Li, S. Bhaskar. Material Research Innovation, Volume 11, Issue 1 ,2007, 3-18. DOI 10.1179/143307507X196167. 3) Ivan Sondi and Branka Salopek-Sondi. Journal of Colloid and Interface Science 2004, 275, 177-182. doi:10.1016/j.jcis.2004.02.012