The effect of dextran 70 on the structure of plasma-derived fibrin gels

Measurements of fiber mass-length ratios and fibrin gel elastic modulus as a function of dextran 70 concentration are reported for fibrin gels derived from human plasma. Dextran 70 at 0.1 mg/ml produces a 50% reduction in the storage modulus of fibrin gels obtained from human plasma diluted 1:10 with saline. Since the fibrin fiber diameter increases as only a weak function of the dextran 70 concentration, the lower elastic modulus most likely results from a reduction in network branch points. Aprotinin is also shown to modulate the dextran effect.