Bactericidal and virucidal ultrathin films assembled layer by layer from polycationic N-alkylated polyethylenimines and polyanions.

In this work, we designed contact-killing ionically cross-linked polymeric thin films using Layer-by-Layer (LbL) technology. A polycation, N,N-dodecyl,methyl-polyethylenimine, with microbicidal activity was layered with a polyanion, such as poly(acrylic acid), to create LbL films highly effective against both airborne and waterborne Escherichia coli and Staphylococcus aureus (Gram negative and positive bacteria, respectively), as well as influenza A/WSN (H1N1) virus. The dependence of the microbicidal activity on the pH during and post-assembly of LbL film formation, the nature of the polycation and polyanion, the number of layers in the LbL film, and other experimental variables was investigated quantitatively. Copyright 2010 Elsevier Ltd. All rights reserved.