The invention relates to a coating comprising a hydrogel layer of a hydrogel of a polysaccharide and polymer brushes attached to the hydrogel layer. The invention also relates to a process for making the coating according to any one of the preceding claims, comprising the steps of: a) providing the hydrogel layer on a substrate, b) attaching an initiator having a radically transferable atom on the hydrogel layer and c) reacting monomers with the initiator to form the polymer brushes attached to the hydrogel layer.
