Biocompatible hydrogels composed of covalently crosslinked, chemically modified hyaluronan (HA), gelatin (Gtn), and heparin (Hp) were synthesized for controlled release of human vascular endothelial growth factor (VEGF) or basic fibroblast growth factor (bFGF). We hypothesized that inclusion of small quantities of heparin in these gels would result in regulated growth...