Hemostatic Ability of Chitosan-Phosphate Inspired by Coagulation Mechanisms of Platelet Polyphosphates

Hemostatic materials have been studied to minimize bleeding time. Recently, polyphosphate (polyP) have received attention as potential hemostatic compounds, which are released from activated platelets. Long polyP chains are essential to form thick fibrin clots. Herein, chitosan is functionalized by covalently tethering phosphate groups to mimic polyP. It is hypothesized that utilizing a known hemostatic polysaccharide, chitosan, and tethering phosphate groups to mimic polyP's functionality show synergistic effect in hemostasis. Five different phosphorylated chitosan conjugates (Chi-Ps), s-Chi-7P, s-Chi-28P, s-Chi-74P, is-Chi-29P, and is-Chi-56P are prepared, where "s" indicates water soluble Chi-Ps and "is" represents water insoluble Chi-Ps. Unexpectedly, an important carbon in D-glucosamine is found, which determines chitosan solubility. Phosphate groups conjugated to C6 carbon resulted in water soluble Chi-P, but conjugation to C3 group exhibited water insoluble behavior. Hemostasis capability showed a positive correlation with the degree of phosphate conjugations regardless of water solubility of Chi-P.