Heparin correlation with structure

The concept that different structural domains on the heparin chains are principally involved for optimal activity in the foregoing interactions could not be perceived in early work on structure-activity correlations, because the activity of heparin has been most frequently evaluated only with whole-blood-clotting tests (such as the U.S.P. assay). Development of assays for specific clotting-factors (especially Factor Xa and thrombin) has permitted a better insight into the mechanism of action of heparin at different levels of the coagulation cascade. 

Fig. 5). Furthermore, RGD peptides were covalently attached to EDC/sulfo-NHS activated carboxylic acid functionalities of heparin. A wide variety of growth factors (such as FGF-2) can be incorporated through noncovalent interactions with heparin (Freudenberg et al. 2009). Biofunctionalisation was found to correlate well with the heparin content of the structurally different materials (type A to C, Figs. 5 and 7), as shown for the attachment of adhesive ligands. This allows for an independent variation of mechanical properties at constant biomolecular characteristics. 

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