There is provided inter alia a substrate with a surface having a
hydrophilic coating comprising a cross-linked
copolymer of components A and B, and optional components C and D; whereincomponent A comprises one or more C2-C16 hydrophilic monomers each bearing one or more
alkene and / or
alkyne groups;component B comprises one or more
hydrophilic polymers each bearing two or more
alkene and / or
alkyne groups;component C, if present, comprises one or more beneficial agents each bearing one or more
alkene or
alkyne groups; andcomponent D, if present, comprises one or more low molecular weight cross-linking agents each bearing two or more functional groups independently selected from
thiol, alkene and alkyne groups;wherein the cross-linked
copolymer is formed by
radical polymerization involving the alkene and / or alkyne groups of components A, B and C (if present) and involving the functional groups of component D (if present);wherein the
hydrophilic coating optionally comprises component E which comprises one or more beneficial agents, wherein component E does not form a
copolymer with components A, B, C (if present) and D (if present);and wherein the
hydrophilic coating is covalently attached to the surface of the substrate.