Different sulphation degree and biological performance of hyaluronic acid as heparin-like molecule

Hyaluronic acid was sulphated and seven derivatives, containing a different number of sulphated groups per disaccharide unit were prepared (HyalS(x) where x can be 1, 2, 2.5, 3,3.5, 3.8, 4). The behaviour of the sulphated hyaluronic acids was studied at different pH's by using several thermodynamic and spectroscopic techniques. The ability of these macromolecules to form Cu2+ complexes in aqueous solution was also investigated. The sulphated hyaluronic acids were studied as heparin-like molecules, thus coagulation and angiogenesis in-vitro tests were performed. The influence of the degree of sulphation on the biological activity is well documented.