[Preparation and hemostatic evaluation of chitosan composite hemostatic membrane].

Objective: To improve the flexibility and hemostatic properties of chitosan (CS)/carboxymethyl chitosan (CMCS) hemostatic membrane by using glycerol and etamsylate to modify CS/CMCS hemostatic membrane. To investigate the mechanical properties and hemostatic capability of modified CS/CMCS hemostatic membrane.

Methods: The 2% CS solution, 2% CMCS solution, 10%, 15%, 20%, 25%, 30% glycerol with or without 0.5% etamsylate were used to prepare CS/CMCS hemostatic membrane with or without etamsylate by solution casting according to ratio of 16 : 4 : 5. The tensile properties were evaluated by tensile test according to GB 13022-1991. Twenty venous incisions and five arterial incisions hemorrhage of 1 cm x 1 cm in rabbit ears were treated by CS/CMCS hemostatic membrane modified by 15% (group A) and 25% (group B) of glycerol, and a combination of them and 0.5% etamsylate (groups C and D). The bleeding time and blood loss were recorded.

Results: The pH of yellow CS/ CMCS hemostatic membrane with thickness of 30-50 microm was 3-4. The incorporation glycerol into CS/CMCS hemostatic membrane resulted in decreasing in tensile strength (7.6%-60.2%) and modulus (97%-99%). However, elongation at break and water content increased 5.7-11.6 times and 13%-125% markedly. CS/CMCS hemostatic membrane adhered to wound rapidly, absorbed water from blood and became curly. The bleeding time and blood loss of venous incisions were (70 +/- 3) seconds and (117.2 +/- 10.8) mg, (120 +/- 10) seconds and (121.2 +/- 8.3) mg, (52 +/- 4) seconds and (98.8 +/- 5.5) mg, and (63 +/- 3) seconds and (90.3 +/- 7.1) mg in groups A, B, C, and D, respectively; showing significant differences (P < 0.05) between groups A, B and groups C, D. The bleeding time and blood loss of arterial incision were (123 +/- 10) seconds and (453.3 +/- 30.0) mg in group C.

Conclusion: CS/CMCS hemostatic membrane modified by glycerol and etamsylate can improve the flexibility, and shorten the bleeding time.