To explore the effect of hydroxybutyl chitosan on the prevention of postoperative peritoneal adhesion in rats. Methods Ninety SD rats (half males and half females) weighing 250-280 g underwent laparotomy with subsequent cecal wall abrasion and peritoneal adhesion. Rats were randomized into 3 groups (n=30 per group): group A, injection of 2 mL hydroxybutyl chitosan solution (2%); group B, injection of 2 mL sodium hyaluronate solution(2%); group C, the abdomen of rat was exposed for 30 seconds and served as control group. The general condition of the rats was observed after operation. The rats were killed 2 and 4 weeks after operation, 15 rats per group at a time, to undergo gross and histologyobservation. The degree of adhesion was evaluated by double-bl ind method. The microstructure of injured electroscope cecal wall in groups A and C was observed with transmission electroscope 4 weeks after operation. Results All rats survived till the end of experiment. At 2 weeks after operation, the adhesion and the hyperplasia of fibrous connective tissue and collagen in groups A and B were sl ight while the adhesion in group C was serious with severe hyperplasia of fibrous connective tissue. According to the measurement classification by Nair histological grading, the difference between groups A and B and group C was significant (P lt; 0.05), while no significant difference was evident between group A and group B (P gt; 0.05). At 4 weeks after operation, the adhesion in group A was mild, and the hyperplasia of fibrous connective tissue and collagen were sl ight; the adhesion and the hyperplasia of fibrous connective tissue and collagen in group C were serious. The levels of group B were between group A and group C. The differences among three groups were significant (P lt; 0.05). Transmission electroscope showed inactive fibroblasts and loose thin collagen fibers in group A, and active fibroblasts and closely collagen fibers arranged in a disorderly manner in group C. Conclusion Hydroxybutyl chitosan can decrease the hyperplasia of fibrous connective tissue and inhibit the activity of fibroblasts significantly, and has a long-term role of preventing peritoneal adhesion.
Objective To study hemostasis of a new chitosan hemostatic powder. Methods Twenty-four adult SD rats were made the models of l iver injury, male or female, and weighing 210-240 g. They were divided into three groups randomly (n=8) depending on different hemostatic powders. The incision of the l iver was treated with 300 mg Yunnan baiyao (group A1), chitosan hemostatic powder of pH6.5 (group B1) and pH7.5 (group C1), respectively. The bleeding time and bleeding amount were recorded. In vitro, with the modified Ree-White method, 2 mL artery blood from New Zealand whiterabbit was added into the 0.2 mL solution of Yunnan baiyao, chitosan hemostatic powder of pH6.5 and pH7.5 (concentration of 0.2 mg/mL), respectively. The blood coagulation time was recorded. The chitosan blood clots of group B2 and group C2 were observed with scanning electron microscopy (SEM). Results The bleeding time of group A1, group B1 and group C1 was (292 ± 31), (261 ± 23), and (224 ± 28) s, respectively, the bleeding amount was (1.63 ± 0.21), (1.47 ± 0.18), and (1.18 ± 0.17) g, respectively, showing statistically significant differences between groups B1, C1, and group A1 (P lt; 0.05), between group C1 and group B1 (P lt; 0.05). The blood clotting time of group A2, group B2, and group C2 was (653 ± 41), (255 ± 20), and (202 ± 11) s, respectively, showing statistically significant differences between groups B2, C2, and group A2 (P lt; 0.05), between group C2 and group B2 (P lt; 0.05). The SEM showed that the blood cells of group B2 and group C2 gathered around the chitosan. Conclusion Chitosan hemostatic powder of pH7.5 has good hemostasis.