Objective To investigate the hemostasis of thermosensitive chitosan hemostatic film. Methods Fifty adult Sprague Dawley rats, male or female and weighing 190-210 g, were made the models of liver injury. The models were randomly divided into 5 groups (n=10) depending on different hemostatic materials. The incision of the liver was covered with the hemostatic materials of 2.0 cm × 1.0 cm × 0.5 cm in size: thermosensitive chitosan hemostatic film (group A), chitosan hemostatic film (group B), cellulose hemostatic cotton (group C), gelatin sponge (group D), and no treatment (group E), respectively. The bleeding time and bleeding amount were recorded. After 4 weeks, the incisions of the liver were observed with HE staining. Results Gross observation showed better hemostatic effect and faster hemostatic time in groups A, B, and C; group D had weaker hemostatic effect and slower hemostatic time; group E had no hemostatic effect. The bleeding time and bleeding amount of groups A, B, C, and D were significantly lower than those of group E (P lt; 0.05). The bleeding time and bleeding amount of groups A, B, and C were significantly lower than those of group D (P lt; 0.05), but no significant difference was found among groups A, B, and C (P gt; 0.05). The liver cells of group A had milder edema and ballooning degeneration than other 4 groups through histological observation. Conclusion The thermosensitive chitosan hemostatic film has good hemostasis effect on the liver incision of rats.
To observe the effect of chitosan/alginate (CTS/ALG) dressings on wound immersed in seawater. Methods Twenty-five healthy SD rats weighing 250-300 g were used to establ ish skin wound model through cutting 1.8 cm circle-shaped wound along spine bilaterally. The left side served as experimental group, and the right side as control group. The wounds were immersed in the prepared artificial seawater for 1 hour, then the experimental group was treated with CTS/ALG dressings, while the control group was treated with sterile gauze. Gross observation was performed andwound heal ing time was recorded. At 3, 5, 7, 10 and 12 days after operation, 2 cm × 2 cm skin tissues including the wounds were removed and underwent HE staining and immunohistochemistry staining using Envision method. Histological change of wound and expression of EGF receptor (EGFR) and bFGF were observed. Results In the experimental group, wound inflammatory response was sl ight and incrustation shrinked faster, while the incrustation in the control group shrinked slowly. The wound heal ing time of the experimental group and the control group was (11.68 ± 0.57) and (12.51 ± 0.54) days, respectively, suggesting there was a significant difference between two groups (P lt; 0.05). In the experimental group, granulation tissue prol iferation, cell infiltration, collagen tissue prol iferation, wound shrinkage and epithel ization appeared at 3 days after operation; regularly l ined collagen tissue, complete epithel ization and occurrence of skin appendages were observed at 10 days after operation; complete wound heal ing was noted at 12 days after operation; while in the control group, at the corresponding time point, late cell infiltration and epithel ization were observed and granulation tissue with ulcer was noted. Immunohistochemistry observation: high expression of bFGF in vascular endothel ial cells and interstitial fibroblasts and high expression of EGFR in vascular endothel ial cells were observed in the experimental group at 3 and 5 days after operation, and their expressions were low at 7, 10 and 12 days after operation; while in the control group, there were no or low expression of bFGF and EGFR at the same time point. Conclusion CTS/ALG dressings can promote the heal ing of wound immersed in seawater, but its mechanism needsfurther study.
To evaluate the cl inical effect of pedical screw systems fixed between lumbar and il ium for treatment of sacral fractures. Methods From June 2003 to June 2009, 21 cases of sacral fracture (29 sides including monolateral 13 cases and bilateral 8 cases) were treated with pedical screw systems to have reduction and fixation. There were 12 males and 9 females, aging 23-59 years (38.2 years on average). Fractue was caused by traffic accident in 12 cases, by fall ingfrom height in 7 cases, and by crash in 2 cases. Screws were inserted into lumbar pedicles and il iac crests. Decompression was used in 4 cases compl icated by sacral nerves injury, and reductions and fixations were used in 12 cases compl icated anterior pelvic or acetabulum injury. The preoperative proximal displacement at the injured side of the pelvis was (16.29 ± 6.47) mm compared with contralateral pelvis. Results All incisions healed primarily with no compl ication of infection. Twentyone patients were followed up 6 months to 6 years. Cl inical heal ing time of fracture was 6-9 weeks. In 4 cases compl icated by S1 or S2,3 nerves injury, the function recovered completely after 4-9 weeks. In other 17 patients, no compl ication of intraoperative nerve injury occurred. All patients could walk and squat after 6-12 weeks of operation. No breakage or displacement of implant occurred. The postoperative proximal displacement at the injured side of the pelvis was (3.51 ± 0.68) mm compared with contralateral pelvis, showing significant difference (P lt; 0.01) when compared with preoperative one. Conclusion It is a novel choice to have reduction and internal fixation for sacral fracture with pedical screw systems fixed between lumbar and il ium. The strict regulation of indication and skill is the key to prevent compl ication.
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.