| Abdominal adhesion is a common clinical problem after abdominal surgery.The incidence of postoperative complications is very high and has many complications which seriously affect the patients’ physical and mental health.At present,there are many kinds of anti-adhesion drugs used in clinical surgery,most of them can only reduce the severity of adhesion to a certain extent,but can not prevent the occurrence of adhesion fundamentally,and the application effect is limited.Therefore,the optimization and innovation of anti-adhesion drugs after operation are necessary to change the recent development of abdominal adhesion.The methods of prevention and treatment of postoperative intraperitoneal adhesion are divided into two categories: drug prevention and barrier prevention,which have their own advantages and disadvantages.The prevention and treatment of drugs are mainly from the point of increasing the celiac fibrinolytic activity,reducing the inflammatory reaction of tissue,accelerating the degradation of extracellular matrix and collagen fiber,playing the role of inhibiting abdominal adhesion.The drawback is that most of the anti-adhesion drugs are liquid materials with poor film-forming property,which results in a short retention time in the injured parts of the wound,and the use of one-component drugs can only play a single role,and can not achieve multi-effect protection.The advantage of barrier prevention and treatment is that it can block the direct contact between the injured part and other organs of abdominal cavity,provide a good repair environment for the damaged peritoneum,and prolong the time of self-repair of mesothelial cells.Its disadvantage is that the solid barrier material is inconvenient to be used during the operation,and the body will react with foreign bodies,resulting in abdominal infection.Because the mechanism of celiac adhesion is complicated and involves many factors,it is difficult to achieve the expected effect by using only drug therapy or barrier therapy.The degree of celiac adhesion will be changed to a great extent if the combination of single component drugs is used.At present,the role of polysaccharides in anti-inflammatory,anti-fibrosis,anti-oxidation and anticoagulant diseases has been gradually concerned by scholars.It also makes up for the defect that solid barrier can lead to foreign body infection,so that drugs can play a most important role.Chitosan is widely used as a commonly used polysaccharide in surgical prevention of adhesions.Chitosan is nontoxic,non irritating,and does not cause immune response.It is a good biomaterial and can be highly absorbed and degraded by organisms.Chitosan has the advantage of promoting blood coagulation,antibacterial activity,accelerating epithelial cell proliferation and increasing tissue fibrinolytic activity,but the defect of chitosan is that its acute hemostatic effect is not ideal.As a commonly used medical dressing,seaweed polysaccharide has a good hemostatic effect and has immunomodulation function.Most importantly,seaweed polysaccharides have good film-forming properties,and the active substances in algae can bind to skin proteins to form biofilm,which is a good barrier material for isolation,but its repair function to damaged tissues is weak.The physiological repair function of it is not as good as that of chitosan.Poly-cellulose not only has the function of hemostasis,but also can improve fibrinolytic activity and fibrinolysis.Chitosan,seaweed polysaccharides and Poly-cellulose have their own advantages and complementary defects.The combined use of the three has not only played a role in the prevention and treatment of adhesions,but also can be used as a barrier material to form films in damaged parts and prolong the time of action of the drugs.This material is a kind of compound material of chitosan gel liquid,which has certain viscosity,ensures the effect of medicine,plays the role of barrier prevention and cure,has the advantage of lubricating abdominal cavity,washing foreign body and so on.Objective:To observe the mechanism of CGLC on the postoperative adhesions by establishing a rat model of intraperitoneal adhesion.Methods:Ninty male Wistar rats were randomly divided into 9 groups(n = 10): Control group,Sham group,Model group,Chitosan group,Poly-cellulose group,carboxymethyl chitosan group,CGLC(Low dose),CGLC(Middle dose),CGLC(High dose).With the exception of Control group and Sham group,the other groups repeatedly and slightly scratched the caecum end and the corresponding abdominal wall to the point of blood leakage,and exposed the caecum to the air to make it fully dry,so as to establish the abdominal adhesion model.The sham operation group was only sutured after laparotomy and no model was made.The other groups were added drugs to the caecum surface and abdominal wall wound before abdominal closure.On the 14 th day after operation,the degree of adhesion was observed,and the adhesions were graded according to the evaluation criteria of Nair and Zuhlke.The injury degree of caecum tissue and proliferation of fibroblasts were observed by HE staining,and collagen deposition on injured surface was observed by masson and Sirius red staining.The effect of CGLC on the expression of fibrosis factor TGF-β1 in the damaged caecum and serum was observed by ELISA 、 QPCR and immunohistochemistry.The expression of t PA 、 PAI-1 and expression of inflammatory related factor IL-6、TNF-α were detected by ELISA、QPCR methods.Western blot was used to detect the expression of fiber-specific proteins ICAM-1,α-SMA and fibrinogen in the injured caecum and the expression of MAPK signal transduction related protein TAK1/p-TAK1、JNK/p-JNK、P38/p-P38.Superoxide dismutase kit and malondialdehyde kit were used to detect the effect of CGLC on the expression of SOD and MDA by spectrophotometry.Results:1.Protective effect of CGLC on postoperative intraperitoneal adhesion in ratsAccording to the evaluation of Nair and Zuhlke adhesion grade,the intraperitoneal adhesion was observed on the 14 th day after operation in rats.It was found that the degree of intraperitoneal adhesion and the incidence of adhesion in rats were significantly decreased by CGLC.The results of HE staining showed that the cecum wall structure of each dose group was clearly visible,the adhesion tissue was small and thin,the serous layer structure was basically repaired,the number of inflammatory cells and fibroblasts was significantly decreased,and the degree of collagen deposition was significantly decreased.The results of Masson staining and Sirius red staining showed that the structure of cecum was clearly visible and the degree of collagen deposition outside serous layer was significantly decreased in each group.In CGLC group,there was almost no collagen deposition in serous layer in high dose group.2.Regulation of CGLC on fibrinolytic system in ratsCompared with the Control group,the expression of TGF-β1 in the damaged cecum and serum in the model group was significantly higher(P<0.01).Compared with the Model group,the expression level of TGF-β1 could be significantly decreased in all dose groups of CGLC.Compared with the three groups of positive drugs,the expression level of TGF-β1 was significantly decreased in all CGLC groups(P < 0.05).There was no significant difference among different dose groups of CGLC,but there was a good dose-effect relationship.Compared with the Control group,the concentration of t PA in the model group was significantly lower,whereas the concentration of PAI-1 was significantly higher than that of the Control group(P < 0.05).In the CGLC group,the expression of t PA was increased significantly and the expression of PAI-1 was decreased significantly than those in the Chitosan group、Poly-cellulose group and Carboxymethyl chitosan group.(P < 0.05)At the same time,compared with the model group,the expression of ICAM-1、α-SMA、Fibrinogen in the CGLC group was significantly decreased(P < 0.01).Compared with the three groups of positive drugs,the expression level of ICAM-1、α-SMA、Fibrinogen was significantly decreased in all CGLC groups(P < 0.05).3.Effect and Mechanism of CGLC on intraperitoneal inflammation in Rats after operationResults showed that the level of the inflammatory cytokine(IL-6、TNF-α)in the CGLC group was significantly lower than those in the model group(P < 0.05);QPCR results were consistant with the results of ELISA.The results of western blot showed that the expression of phosphorylated TAK1,phosphorylated JNK,phosphorylated P38 was decreased and the activation of MAPK signaling pathway was inhibited by CGLC.4.Effect of CGLC on oxidative stress induced by intraperitoneal tissue injury in rats after operationCompared with the model group,the activity of antioxidant enzyme(SOD)was significantly increased,and the content of MDA in serum was significantly decreased in CGLC group.Conclusion:1.CGLC can reduce the degree of adhesion formation and improve the pathological injury of adhesion site in rats.It has a good preventive effect on the formation of postoperative intraperitoneal adhesions.2.CGLC can inhibit the expression of TGF-β1 and reduce the fibrinolytic system activity so that alleviate the extent of peritoneal fibrosis.CGLC can improve the activity of plasminogen activator(t PA),decrease the activity of inhibitor(PAI-1),maintain fibrinolytic homeostasis,degrade fibrin,effectively reduce fibrin deposition and reduce the formation of abdominal adhesion.3.CGLC can decrease the expression level of inflammatory cytokines in the abdominal cavity after operation,regulate the expression of MAPK inflammatory pathway,and inhibit the inflammatory response in the abdominal cavity.4.CGLC can enhance the activity of antioxidant enzymes,scavenge excessive free radicals and peroxide,reduce oxidative stress and prevent physiological damage caused by oxidative damage.Summary:The experimental results show that CGLC can significantly reduce the incidence of adhesion and reduce the severity of adhesion formation,and it has a good preventive effect on postoperative abdominal adhesion in rats.Subsequently,we explored the mechanism of anti-adhesion effect of CGLC at molecular level.It was clear that CGLC could inhibit the expression of TGF-β1,thus decrease the degree of intraperitoneal fibrosis.In addition,we observed the expression of plasminogen system related factors t PA and PAI-1,and confirmed that CGLC could activate plasminogen activator and inhibit the expression of plasminogen activator inhibitor.On the other hand,because intraperitoneal adhesion is closely related to inflammatory response,we detected the expression of inflammatory factors and inflammatory pathways and found that CGLC can significantly reduce postoperative inflammatory response.Moreover,CGLC can reduce oxidative stress induced by tissue injury,improve antioxidant enzyme activity,accelerate free radical scavenging and maintain redox balance.Through the study of various anti-adhesion mechanisms,this experiment provides a good experimental basis for the full development and utilization of CGLC in the prevention of postoperative adhesions,and provides an effective reference for the prevention of intraperitoneal adhesion by combined use of drugs. |
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