Chemical modification of heparin and heparosan.

Heparin is a potent clinically used anticoagulant. It is a heterogeneous mixture of polymers that contain a variety of sulfation patterns. However, only 3-O sulfonated heparin pentasaccharide units have been proven to bind to antithrombin and elicit an anticoagulant response. Heparins with other sulfation patterns are able to bind to a variety of other proteins such as FGF, VEGF, and CXCL-3. By modulating heparin's sulfation pattern, it is possible to generate polymers that can regulate biological processes beyond hemostasis. Here we describe a variety of simple chemical modification methods, N-acetylation, N-deacetylation, N-sulfation, O-sulfation, 2-O desulfation, and complete desulfation, to prepare heparin-like polymers with distinct sulfation patterns.