The most important advances in the field of biomaterials over the past few years have been in bioactive biomaterials. Materials have been developed to incorporate bioactivity through biological recognition, including incorporation of adhesion factors, polyanionic sites that mimic the electrostatics of biological regulatory polysaccharides, and cleavage sites for enzymes involved in cell migration. Materials have also been developed to be active in biological environments by undergoing phase changes in situ, including transformations from liquid precursors to solids and from soluble materials to materials that are immobilised on tissue surfaces. [on SciFinder (R)]