Solid substrate coated with an aminopolysaccharide

A process for the preparation of a solid substrate, the surface of which has been modified to introduce hydrophilic reactive groups thereon, such modification being effected using a primer which comprises a first polysaccharide which contains reactive amino and hydroxyl groups, said process comprising the following steps:

• (a) providing a substrate, the surface of which is to be modified by the addition of hydrophilic reactive groups;
• (b) preparing a solution which contains a first polysaccharide which first polysaccharide contains reactive amino and hydroxyl groups and further contains a second polysaccharide which comprises vicinal hydroxyl groups or which contains both amino and hydroxyl groups in a vicinal position, and wherein said second polysaccharide is subjected to periodate oxidation resulting in the production of at least two dialdehyde functional groups and further resulting in the stabilization of the first polysaccharide by cross-linking;
• (c) coating said surface with the solution of step (b);
• and
• (d) precipitating said crosslinked first polysaccharide from said solution thereby producing a substrate which has been modified by the introduction of reactive hydrophilic groups.