A method of producing a hydrogel compromising a spatially-controlled, three-dimensional distribution of one or more bioactive signals is provided. The method compromises illuminating the hydrogel, wherein the hydrogel compromises a polymer bound to a peptide comprising a photolabile protected amino acid, wherein at least one portion of the hydrogel is illuminated to deprotect the protected amino acid, thereby converting the protected amino acid to a deprotected amino acid. Preferably, the deprotected amino acid is a substrate for an enzyme in at least one portion of the hydrogel. The method further comprises the step of contacting the hydrogel with the enzyme and a peptide comprising a bioactive signal, wherein the enzyme can form a bond between the substrate and the peptide comprising the bioactive signal, thereby producing a hydrogel compromising a plurality of bioactive signals occupying three dimensions of the hydrogel within at least one portion of the hydrogel subjected to illumination.
