Preparation And Characterization Of Anti-Adhesion Membranes Based On Chitosan

Post-operational adhesion is a popular problem in surgery that often makes a successful operation be defeated. At present, the way of "short term barrier" is often used as an effective means to prevent post-operational adhesion. The materials such as PLA, PU and so on are used at present. While these materials are all acidic ones. And the degradation products of such materials may induce inflammation.Chitosan is a biodegradable natural polymeric material having good physical and biological properties. It was reported that chitosan could enhance coagulation, suppress fibroblast growth, and improve interstitial cell growth. Chitosan could be used to prepare controlled-release medicine membrane, artificial skin, and anti-adhesion membranes for post-operative application, etc. However, few chitosan membranes have been used in clinical practice. One of the important reasons is that the preparation by conventional methods requires a long time, and the pure chitosan membrane is not good enough in its strength and flexibility. The scope of this study is to find an effective method and appropriate additives to prepare chitosan composite membranes with good physical and biological properties.Glycerol is a good additive that could make the chitosan composite membranes have good flexibility and keeps the wound dry. In this paper, chitosan/glycerol blend membranes were prepared by the sol-gel transformation method. The present method takes about 6 hours to get a flexible membrane with fine appearance. The physical and biological properties of the chitosan/glycerol membrane were also investigated. The result shows that the mechanical properties of blend membranes greatly increased with the increase of glycerol. The chitosan/glycerol membrane has best properties with 8%(wt) glycerol and fixed at 70癈 for 2 hours in a mixed fixation agent composed of ethanol, glycerol and sodium hydroxide. The animal test shows that such a membrane could be used practically, however, the membrane became much hard and small when glycerol lost that would do harm to organize.Gelatin is a flexible polymer that has the same effect as glycerol. In this paper chitosan/gelatin blend membrane was prepared by the solution casting. Addition of gelatin could improve both physical-chemical properties and biological properties. XRD, SEM, DSC,percent water absorption and mechanical properties were characterized. The mechanical properties of chitosan/gelatin blend membranes greatly increased with the increase of gelatin content. The best tensile strength values were 17.3MPa in wet state and the elongation at break values were 99% in wet state. And the blend membrane also has good water absorption. The best values were 123% that could keep the wound dry and breathe freely. The animal test shows that the membrane can control the growth of fibroblast, and has good anti-adhesive effect. The addition of the gelatin provides the possibility of controlling degradability.D-glucosamine hydrochloride is also blended with chitosan to prepare anti-operational adhesion membrane by solution casting. D-glucosamine hydrochloride is abstracted from natural chitin, and it can diminish inflammation. The result shows that the rate of degradation improves with the increase of D-glucosamine hydrochloride content. But the animal test shows that D-glucosamine hydrochloride hasn't the effect of diminish inflammation.