Molecular weight-dependent anticoagulation activity of sulfated cellulose derivatives

This work is to examine the molecular weight (MW)-anticoagulation activity relationship of sulfated cellulose derivatives (cellulose sulfates, CS). The initial CS with a degree of substitution (1.59) was prepared by homogeneous sulfation of microcrystalline cellulose in an ionic liquid [C(4)mim]Cl. It was then hydrolyzed in a dilute acidic solution and separated into four MW fractions of 59, 23, 10 x 10(3) g/mol and below 2.7 x 10(3) g/mol. The anticoagulation activities based on in vitro assays of coagulation time and coagulation factors in human plasma showed a positive correlation with the MW of CS, while the activity assay of clotting time in rats exhibited a negative correlation with the MW 10-59 x 10(3) g/mol, and the fraction with a MW < 2.7 x 10(3) g/mol exhibited a more moderate and durable activity. The results indicate that MW is a major factor on the anticoagulant properties of CS derivatives and higher MW range is favorable for in vitro, and lower MW suitable for in vivo applications.