A method for making a biomaterial comprising providing at least one polypeptide fraction chymotryptically isolated and extracted from fibroin, and adding the at least one extracted polypeptide fraction to a hydrogel precursor before gelling, wherein the at least one isolated and extracted polypeptide fraction is selected from a soluble fraction Cs, and a precipitated fraction Cp. A biomaterial comprising at least one of the isolated and extracted polypeptide fractions incorporated in a hydrogel or a hydrogel precursor. Use of the biomaterial for constructing, regenerating, repairing, replacing or augmenting soft or hard tissue; as an in vitro or in vivo construct; as a coating material; or as a cell, molecule or particle delivery medium. Use of the isolated and extracted polypeptide fraction Cs for promoting osteoinduction, osteoconduction or osteogenesis. Use of the isolated and extracted polypeptide fraction Cp for enhancing a mechanical compressive modulus of a material into which it is incorporated.