Controlling the supramolecular organisation of adsorbed collagen layers.

The supramolecular organisation of collagen adsorbed on polymer substrates was investigated as a function of properties of the substrates (chemical nature, roughness) and of characteristics of the collagen solution (concentration, state of aggregation) as well as details of the preparation procedure (adsorption time, drying rate). Elongated structures are formed at the interface by assembly of collagen molecular segments protruding into the solution. This is favoured by using a hydrophobic and smooth substrate, by increasing the adsorbed amount and by increasing the adsorption time, even beyond stages at which the adsorbed amount does no longer vary. Collagen adsorbed at low amount on hydrophobic substrates strongly reorganises into a net-like pattern if drying is performed at low rate. This is due to dewetting and collagen displacement by the water meniscus. Applications derived from the control of collagen organisation are presented. Nanostructured polymer surfaces were created starting from a collagen template. The attachment and the cytoskeletal organisation of mammalian cells (MCF-7/6) were also shown to depend on collagen organisation.