Described herein are modified gelatins or the pharmaceutically-acceptable salts or esters thereof comprising at least one actinically crosslinkable group covalently bonded to gelatin. The modified gelatins are useful in producing composites that ultimately can be used to produce three-dimensional engineered biological constructs. The composites are the polymerization product between the modified gelatin and at least one actinically crosslinkable macromolecule. Methods for making the modified gelatins are also described herein.