Oxidized regenerated cellulose-based hemostat with microscopically gradient structure

Partially water-soluble oxidized regenerated cellulose carboxylate sodium (ORC-Na) materials have been prepared by controlled neutralizing oxidized generated cellulose (ORC). The carboxyl were converted into sodium carboxylate as evidenced by FT-IR, and carboxyl content decreased from 18.41% to 0.98%, with enhancing water solubility of ORC-Na to form gel, and SEM-EDX revealed that the sodium carboxylate groups presented in a gradient distribution from the exterior to the interior of fiber. ORC-Na introduced a new hemostatic mechanism, i.e., forming gel to mechanically seal off the crevasses of vessels. Due to its excellent water solubility and 5.23% carboxyl, ORC-Na-3 possessed optimum hemostatic efficiency and demonstrated a capability to stop bleeding within shortest time (102 and 138 s) with the least blood loss (0.886 and 1.006 g), and implantation test showed ORC-Na-3 could be absorbed in less than 2 weeks with no pathological response remaining. In conclusion, ORC-Na-3 is an efficient hemostat with optimum biodegradability.