A method and a composition for delivery of a biomaterial to an animal cell or a tissue, the composition includes (a) a biomaterial (b) a biodegradable cross-linker portion having a hydrolyzable bond, wherein the biodegradable cross-linker portion is covalently bound to the biomaterial and (c) a substrate, wherein the substrate is covalently bound to the biodegradable cross-linker portion, provided that the biodegradable cross-linker is adapted to hydrolyze by breaking the hydrolyzable bond and thereby release and deliver the biomaterial. A process of making the composition is also provided.