Biomedical Engineering Reference
In-Depth Information
5
Silanization with APTES for Controlling the
Interactions Between Stainless Steel and
Biocomponents: Reality vs Expectation
Jessem Landoulsi
1
, Michel J. Genet
2
, Karim El Kirat
3
,
Caroline Richard
4
, Sylviane Pulvin
5
and Paul G. Rouxhet
2
1
Laboratoire de Réactivité de Surface,
Université Pierre & Marie Curie -Paris VI,
2
Institute of Condensed Matter and Nanosciences - Bio & Soft Matter,
Université Catholique de Louvain,
3
Laboratoire de Biomécanique et Bioingénierie,
4
Laboratoire Roberval,
5
Génie Enzymatique et Cellulaire,
Université de Technologie de Compiègne,
1,3,4,5
France
2
Belgium
1. Introduction
The surface of biomaterials is frequently chemically modified with the aim to modify the
physicochemical properties (hydrophobicity, electrical charge, solvation) which control the
interactions with biomolecules and consequently with cell surfaces, or to retain biochemical
entities which are specifically recognized by the cells (Williams, 2010). Regarding inorganic
materials, widespread procedures involve self-assembly of alcane thiols on gold, silver,
copper or platinum (Wink et al., 1997). However, these substrates have limited interest in
biomedical applications. Other procedures consist in grafting organosilanes on silica and
other metal oxides (Weetall, 1993). The use of silane coupling agents has been reported in
various biomaterials researches, such as surface modification of titanium (Nanci et al., 1998),
natural fiber/polymer composites (Xie et al., 2010) or dental ceramics (Matinlinna et al.,
2004; Matinlinna & Vallittu, 2007).
The silanization reaction at interfaces is complex and there is still considerable debate on the
retention mechanisms and on the organization of the interface (Gooding & Ciampi, 2011;
Haensch et al., 2010, Suzuki & Ishida, 1996). Depending on the nature of reactive moieties
bound to Si in the silane (typically Cl or alkoxy group) and their number, and on the
reaction conditions (particularly the presence of water), the relative importance of covalent
binding to the surface, oligomerization, polymerization along the surface plane, three-
dimensional polymerization may possibly vary. The efficiency of the surface modification is
often demonstrated by its influence on biochemical or biological activity. However the
nature of the interface produced is difficult to characterize, which limits the guidelines
