The Study On The Anti-immersed Collagen Combined Medical Dressing

In the first aid of war wound and daily treatment, excessive blood loss is the main Cause of death. Due to the characteristics about highly activity, absorptivity and innocuous, the biomedical materials are regarded as the most effective hemostatic materials. Collagen is a frequently hemostatic material with good biocompatibility and hemostatic properties. It can prevent the loss of water and body fluid, what’s more, it has a good affinity and adhesive force with wound. It can accelerate the speed of healing by promote the growth of capillary and neonatal granulation tissue. Chitosan is a kind of natural degradable material which is widely used in biomedical field with good biocompatibility and degradability. Calcium Alginate is a kind of salt has ample Ca2+ epurated from seaweed, and has very high effect of hygroscopicity. In the process of hemostatis, physiogenic blood clotting is an important part.Ca2+ can promote the creation of thrombin so as to accelerate hemostatis.Experiments of single factor and orthogonal were enforced to get a best formula combination about Collagen, Chitosan and Calcium alginate. After freeze drying, a new kind of combined sthptic sponge was prepared. Several kinds of water proofing materials were sieved and united with Collagen/ Calcium Alginate / Chitosan matrix sponge to formed anti-immersed medical dressing. This topic preliminary studied the surface features, structure, hemostasis, wound healing and biosafety of the combined sthptic sponge so as to provide the theoretical basis of the study and application about a new kind of anti-immersed hemostatic material.1. The suitable concentration of Collagen, Calcium alginate and Chitosan on blood coagulation was detected by blood clotting test, respectively. L9(33) orthogonal test design was used to exam the best proportion of Collagen, Chitosan and Calcium alginate by Lee-white blood clotting test. The results showed that the best proportion of Collagen, Calcium alginate and Chitosan was 20: 0.4: 0.1(mg/m L). Froze drying method was used to prepare the Collagen/ Calcium Alginate / Chitosan Matrix(CCCM) sponge. Scanning electron microscope was used to detect the surface features, and infrared spectroscopy was used to detect the chemical bond modification. Hydroscopicity and porosity of CCCM were detected by ordinary method. The results indicated that CCCM was a porosity lamellar membrane, had a good water absorption, and several chemical reactions were happened between the 3 materrials.2. To detect the hemostatic ability of CCCM sponge, arteria auricularis, pars dorsalis full-thickness skin wounds bleeding and hepatic hemorrhage of New Zealand rabbits were used to detect the blood clotting indexes. The effect of CCCM sponge on blood platelet aggregation and adhesion was detected. The effect of CCCM sponge on wounds healing was detected by the pars dorsalis full-thickness skin wound healing model of New Zealand rabbits. The results showed that CCCM had a more effective ability on hemostasis and wound healing. It could shorten the bleeding time and bleeding loss. What’s more, it could decrease the inflammation and facilitate the expression of several growth factors profiting the wound healing.3. In order to evaluate the biosafety of CCCM sponge, According to the national standards, cytotoxicity test, cell clone test, skin sensitivity test, total body acute toxicity test and skin irritation test were established. The results showed that CCCM sponge could be regard as a safe dressing.4. On the above results, electrospinning technique was used to spin collagen and chitosan to the alginate dressing pars dorsalis full-thickness skin wound healing model and cytotoxicity test were used to study the wound healing effects and biosecurity. The results indicated the collagen/chitosan electrospinning alginate dressing could effectively decrease the inflammation, facilitate the wound healing and stimulating the expression of seveval growth factors correlating to wound healing, otherwise, little toxicity to cells had been detected.5. According to medical industry standard, the anti-immersed of sea water animal model was built, and excessive sticky PU membranes from Zibo Nachl Bioscience Technology Co., Ltd. and Zhejiang Topmedical Dressing Co., Ltd were adopted to detected the effect on sea water anti-immersed, bacteria resistant and water resistant. The result showed that Topmedical polyurethane membranesatisfied all the demands. The anti-immersed Collagen combined medical dressing were made of PU membranes screened and CCCM/ES.by agglutinating. The anti-immersed of sea water animal wound healing model was built to study the function of these two anti-immersed Collagen combined medical dressings. The result revealed that these two combined medical dressings can also anti-immerse the sea water and accelerated the wound healing. There was no significant difference due to the insufficient samples.