Abstract: The present invention provides peptide derivatives with a specific affinity for glycosaminoglycan molecules. These peptide derivatives include multimers as well as chemically modified peptides and may be prepared by a variety of methods. The peptides of the invention have numerous functions, including but not limited to use as inhibitors of glycosaminoglycan-mediated signaling events and targeting agents. Peptides of the invention may be directed against any glycosaminoglycan, including hyaluronic acid, chondroitin sulfate A, chondroitin sulfate C, dermatan sulfate, heparin, keratan sulfate, keratosulfate, chitin, chitosan 1, and chitosan 2. The peptide derivatives of the invention also have therapeutic uses in the treatment and prevention of diseases involving inflammatory diseases, cancer, and cancer metastasis, autoimmune diseases, etc.