In vivo and in vitro evaluation of gelation and hemostatic properties of a novel tissue-adhesive hydrogel containing a cross-linkable polymeric micelle.

There is a clinical requirement for a local hemostat that arrests bleeding from both suture holes and cross-sectional surfaces of parenchymatous organs. A novel tissue-adhesive hydrogel was prepared that contains a cross-linkable polymeric micelle consisting of poly(ethylene glycol)-poly(DL-lactide) block polymers, and, by means of a rheometer, the factors that affect the hydrogel's gelation properties was clarified. The storage modulus and the gelation time greatly depended on both the pH and the concentrations of both the polymeric micelle and polyallylamine solutions. Furthermore, the hemostatic potential of the hydrogel in a mouse hemostasis model was evaluated under optimal conditions as determined by the rheometer. The average amount of bleeding from the mouse liver was 172.9 mg (S.D. 69.7 mg, N = 7) in the control experiments, whereas it was 20.1 mg (s.d. 13.2, N = 7) when the hydrogel was applied to the wound (p = 0.002). The result demonstrated that the novel synthetic hydrogel possessed a significant hemostatic potential as a local hemostat.