title: Influence of surface features on the adhesion ofStaphylococcus epidermidisto Ag-TiCN thin films.
abstract: Staphylococcus epidermidishas emerged as one of the major nosocomial pathogens associated with infections of implanted medical devices. The initial adhesion of these organisms to the surface of biomaterials is assumed to be an important stage in their colonization. The main objective of this work is to assess the influence of surface features on the adhesion ofS. epidermidisto Ag-TiCN coatings deposited by dc reactive magnetron sputtering. The structural results obtained by x-ray diffraction show that the coatings crystallize in a B1-NaCl crystal structure typical of TiC0.3N0.7. The increase of Ag content promoted the formation of Ag crystalline phases. According to the results obtained with atomic force microscopy, a decrease on the surface roughness of the films from 39 to 7 nm is observed as the Ag content increases from 0 to 15 at.%. Surface energy results show that the increase of Ag promotes an increase in hydrophobicity. Bacterial adhesion and biofilm formation on coatings were assessed by the enumeration of the number of viable cells. The results showed that the surface with lower roughness and higher hydrophobicity leads to greater bacterial adhesion and biofilm formation, highlighting that surface morphology and hydrophobicity rule the colonization of materials.
authors.affiliation: GRF-CFUM, University of Minho, Campus of Azurém, 4800-058 Guimarães, Portugal; IBB-Institute for Biotechnology and Bioengineering Centre for Biological Engineering, University of Minho, Campus of Gualtar, 4700-057, Portugal.
authors.forename: Isabel
authors.initials: I
authors.lastname: Carvalho
authors.affiliation: IBB-Institute for Biotechnology and Bioengineering Centre for Biological Engineering, University of Minho, Campus of Gualtar, 4700-057, Portugal.
authors.forename: Mariana
authors.initials: M
authors.lastname: Henriques
authors.affiliation: CEMUC Mechanical Engineering Department, University of Coimbra, 3030-788 Coimbra, Portugal.
authors.forename: João Carlos
authors.initials: JC
authors.lastname: Oliveira
authors.affiliation: GRF-CFUM, University of Minho, Campus of Azurém, 4800-058 Guimarães, Portugal.
authors.forename: Cristiana Filipa
authors.initials: CF
authors.lastname: Almeida Alves
authors.affiliation: CEMUC Mechanical Engineering Department, University of Coimbra, 3030-788 Coimbra, Portugal.
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Piedade
authors.affiliation: GRF-CFUM, University of Minho, Campus of Azurém, 4800-058 Guimarães, Portugal; CEMUC Mechanical Engineering Department, University of Coimbra, 3030-788 Coimbra, Portugal.
authors.forename: Sandra
authors.initials: S
authors.lastname: Carvalho
keywords: 20.11; 30.1; biofilm; biomaterial; hydrophobicity; microorganism adhesion; sputtering