AVS 52nd International Symposium
    Plasma Science and Technology Tuesday Sessions
       Session PS-TuP

Paper PS-TuP10
Plasma-Deposited Silver Containing Nanocomposite Coatings with Bactericidal Properties

Tuesday, November 1, 2005, 4:00 pm, Room Exhibit Hall C&D

Session: Plasma Science and Technology Poster Session
Presenter: P. Favia, University of Bari, IMIP-CNR, Plasma Solution Srl, Italy
Authors: P. Favia, University of Bari, IMIP-CNR, Plasma Solution Srl, Italy
E. Sardella, University of Bari, Italy
M. Nardulli, University of Bari, Italy
R. Gristina, Institute of Inorganic Methodologies and Plasmas (CNR-IMIP) Bari
R. d’Agostino, University of Bari, IMIP-CNR, Plasma Solution Srl, Italy
Correspondent: Click to Email
Silver has been considered for centuries for its antibacterial properties,@footnote 1@ that are explained with different mechanisms, including strong interactions with thiol groups of the respiratory enzymes of bacteria. Silver has a broad spectrum of action, from anaerobic bacteria to viruses, yeasts, and fungi. The overuse of silver compounds causes argyria, a discoloration of the skin, often due to the uptake of improperly prepared and unstable colloidal silver. For this reason the interest is often focused on products for topical therapies@footnote 2,3@ instead of systemic, able to release in a controlled way the minimum quantity of silver effective. Nanocomposite coatings (i.e. dispersions of Ag clusters embedded into an organic/inorganic matrix) are under investigation in our lab as silver delivery systems, as alternative to available medical products, since they allow to control the release rate of silver as a function of their chemical composition.@footnote 4,5@ In this work the attention is focused on the ability of such coatings to release a minimum quantity of silver in cell-culture medium without losing bactericidal effect. Coatings have been deposited in RF (13.56 MHz) Glow Discharges fed with a mixture of Diethyleneglycole di-methyl ether (DEGDME) and Ar. Sputtering from the Ag-coated cathode of the reactor occured simultaneously in certain conditions, to give Ag clusters dispersed in the Polyethyleneoxide (PEO)-like coating. Different PEO-like and Ag/PEO-like coatings have been deposited, that have been characterized with different surface analysis techniques. The role of silver and its cytotoxycity in cell culture media has been evaluated with 3T3 Murine Fibroblasts at different time of incubation. The bactericidal effect of Ag+ ions was evaluated with different bacteria. Biological results have been correlated with the quantity of silver released in water at 37°C, as measured with ICP Emission spectroscopy. Acknowledgements: The project MIUR-FIRB RBNE01458S_006, is gratefully acknowledged for funding this research @FootnoteText@ @footnote 1@ Russell et al, Hugo. Antimicrobial Activity and Action of Silver. Prog Med Chem. 1994, 31:351;@footnote 2@ Thomas et al, J Wound Care 2004; 13(9):392;@footnote 3@ Dowling et al, Thin Solid Films 2001; 398-399: 602;@footnote 4@ Favia et al, Plasmas and Polymers 2000, 5(1):1;@footnote 5@ Sardella et al, Plasma Proc. and Polym., 2004, 1:63.