Study Of Collagen From Squid Skin As Medical Hemostatic Material

The collagens are a family of fibrous proteins found in all multicellular animals,and they are the predominant protein of the extracellular matrix and represent about25%~30%of their total proteins. They comprise the major structural element of allconnective tissues and are also found in the interstitial tissue of virtually all organs,where they contribute to the stability of tissues and organs, and maintain theirstructural integrity. Due to their unique biochemical features, collagens have beenutilised in various fields of industry, such as biomedical and pharmaceuticalapplications, materials, food and beauty and cosmetics. Generally, in the collagenindustry, skins and bones of mammals, cattle and pig, etc., have been used as rawmaterials. Nevertheless, after the outbreaks of bovine spongiform encephalopathy andfoot-and-mouth disease, it has been of great interest to find collagens from alternativesources, such as those that can be obtained from the environment. And also the use ofaquatic collagen, instead of mammalian collagen, has numerous rewards. This paperextracts collagen from squid skin and study the hemostatic effect of the collagensponges which modified by chemical and/or physical method. The main ideas asfollow:(1) Acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) from freshsquid skin were isolated and characterized. The prepared collagen was evaluated byUV, FTIR, SDS-PAGE and amino acid analysis. The results show that the maximumabsorption peak of ASC and PSC were both about220nm, SDS-PAGE and aminoacid analysis and FTIR analysis showed that they were typical type I collagen.(2) Extracted collagens were lyophilized to prepare for collagen sponges, andthen crosslinked using1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC)treatment and dehydrothermal (DHT) treatment and EDC/DHT treatment, respectively.To evaluate the feasibility of the collagen as hemostatic sponges by measuringwater-binding capacity, degree of crosslinking and digestion performance, and usingscanning electron microscope (SEM) to observe their shapes. SEM showed thecollagen sponges were all porous. The modified collagen sponges all have a certainwater-binding capacitity, and different crosslinking methods have different effects onit. The three crosslinking methods all have brought about crosslinking and collagenmolecules retain triple helical structure, increased resistance to enzymatic capacity, improved the physical and chemical properties and mechanical properties of collagensponges, wherein the crosslinking degree of DHT treatment is the lowest, less than10%; and the crosslinking degree of EDC or EDC/DHT treatment is better, canreach34to52%range, significantly superior to DHT treament.(3) Rabbit ear wound bleeding test and liver bleeding test were measured toevaluate hemostatic properties of modified collagen sponges. Results of animalhemostatic experiments showed that ASC-E, PSC-E, ASC-E/D and PSC-E/D the fourgroups of collagen sponges all can to a certain role in hemostasis of wound up,effectively shorten the bleeding time, less blood loss, and do rapid hemostatic effect,the hemostatic effect of PSC-E is best, especially.