Development Of Collagen Hemostatic Sponge

Collagen is the most abundant protein in animal body, playing support, protectionand connection roles. At present, collagen has been widely used in medicine industry,pharmaceutical industry, food industry, daily chemical industry, collagen biosynthesisand modification industry.In this paper, the ficin and pepsin were used to extract collagen from the bovinetendon in order to study on extraction and purification process of collagen.Experimental results showed that when the temperature of the extraction experiment at4℃, the optimum proportion of ficin and bovine tendon was1:25, and for pepsin, theratio was1:10. The rate of production achieved about77%. The purify process of rawcollagen included fine filtration, centrifugation, salting out and dialysis. Fine filtrationwas a little better than centrifugation. For salt precipitation, the optimum concentrationof sodium chloride was3mol/L, time of36hours, the dialysis time should be more thanseven days. The extracted protein was confirmed to be collagen by FTIR, UV spectralanalysis and amino acids analysis. In addition, the extracted collagen had high-purityanalyzed by SDS-PAGE gel electrophoresis experiment. Collagen fiber in a solutionwas observed by transmission electron microscopy.Glutaraldehyde was used to crosslink collagen to enforce the properties of heatresistance and mechanic strength. Collagen sponge was prepared by vacuum freezedrying technology. After crosslinked, the collagen did not denature. DSC and TGshowed the shrink temperature and thermal decomposition temperature were bothincreased by13℃and11℃. SEM showed the porous structure of the sponge graduallyreduced, and the structure tends to be more regular and dense after glutaraldehyde crosslinked. Water absorption and porosity of crosslinked collagen sponge declined, and thepH of the dissolution changed little. The effects of the acidity of collagen solution,freezing temperature, concentration of collagen and the freezing time, on themicrostructure of the collagen sponge were researched. The results indicated that theacidity of the collagen solution and the freezing temperature are the main factors tocontrol the microstructure of sponge. Selected collagen sponge which microstructurewas better to do animals experiments, the hemostatic properties were evaluated byrabbit ear artery injury model and rabbit liver injury model. Experiment results showedthe collagen sponge without crosslinked had the best hemostatic effect. For the rabbit ear artery, the average bleeding time was148s, the amount of bleeding was0.77g, forthe rabbit liver, the average bleeding time was202s, the amount of bleeding was1.72g.The collagen sponge hemostatic properties slightly better than standard. Experimentsalso indicated that the glutaraldehyde crosslinking could decrease hemostatic properties.