Sol-gel nanostructured antibiofilm glass surfaces

M. E. VILLANUEVA; D. E. CAMPOROTONDI; G. J. COPELLO; S. TEVES; L. E. DIAZ

Potrero de los Funes, San Luis

Congreso; XLVII Reunión Anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular; 2011

Sociedad Argentina de Investigación Bioquímica y Biología Molecular

A biofilm is defined as a community of micro-organisms irreversibly attached to a surface, producing extracellular polymeric substances , exhibiting an altered phenotype compared with corresponding planktonic cells, especially with regard to gene transcription, and interacting with each other. Various types of surfaces in clinical or industrial settings are prone to unwanted biofilm attachment. In order to prevent the large doses of antibiotics that are required to eradicate them, superhydrophobic surfaces are being developed as alternative. These surfaces are shown to prevent contact between a bacterium and surface attachment points and they are generally made from a low energy material with a highly developed microstructure, some incorporating two different length scales in its roughness.In this work, we describe a simple method to fabricate sol-gel nanostructured glass coatings to control bacterial adhesion. These surfaces were manufactured by coating glass slides with a mixture of Aminopropyl trietoxysilane and Tetraetoxysilane in order to functionalize the surface with amino groups. Then, three  different sizes of silica particles: nanoparticles A (NPsA: 28 nm), nanoparticles B (NPsB: 300nm) and microparticles (MPs: 1.5 μm) were also functionalized with NH2 groups and attached to the surface by glutarahaldeyde crosslinking. The effect of different proportions of the particles (0:100, 25:75, 50:50 MPs:NPs) and the effect of joining the particles in different layers interspersing two different sizes of silica particles (NPsA and MPs B) were studied. Finally, the surfaces were treated with dodecenyl succinyc anhydride in anhydrous ethanol (1/10, 1/100, 1/1000) or with trymethylchlorosilane (TMCS). Surfaces  inhibition of biofilm formation was analyzed by exposing them to Pseudomonas spp.