Preparation And Characterization Of Composite Sponge Of Cellulose Fiber In Different Sizes And Collagen

Collagen is kind of natural biological material, which is essentially scaffold for body with little antigen. With development of bio-engineering and tissue engineering, collagen has been paid been more attention. But pure collagen has a fatal disadvantage that it shows poor mechanical properties and fast degradation, which limit its wide use. Cellulose and its derivatives are easy to get, high strength, non-toxic and easily biodegradable. So they are commonly used in a variety of areas, such as chemical field and food field. They are both natural materials and they can compensate for disadvantages of each other’s.Based on this, this paper has prepared composite sponge of cellulose in different sizes and collagen. For the first, this paper prepared oxidized regenerated cellulose(ORC) by NO2/CCl4 method, and proved its oxidizing effect by FT-IR, carboxyl calculation and so on. Then this paper prepared OMCC by TEMPO oxidation system and determined the best conditions of TEMPO 0.05 g, Na Br 0.48 g, Na Cl O 15 m L, with reaction temperature at 20℃ and p H 10.8, to keep reaction time 3h. In the following, this paper prepared CN through H2SO4 method and determined the optimum conditions for the acidification process of sulfuric acid concentration of 64wt%, the reaction temperature at 40℃ and reaction time of 2h. And then this paper has prepared OCN as the above method. The carboxyl amount on the surface is 18%, 17.76% and 17.24% separately. And then this paper has determined the optimum conditions for reforming collagen which is collagen concentration of 1%, the acid concentration of 1%, the pre-freeze time of 12 h, pre-freezing temperature of-20℃.In the last part, this paper has constructed 5 systems to discuss the influences of different sizes and amounts of cellulose have on properties of collagen. The added cellulose is in different sizes, which are less than 1mm, 1cm, 5cm, micron-level and nano-level. These celluloses are mixed with collagen in different amounts, such as: 1%, 3%, 5%, 10%. Then dried composite cellulose/collagen sponges are made to test the properties, which are aperture test, water absorption, stretch test and compression test. SEM pictures showed that the fiber was either inlayed in the slice collagen or connected with the threadiness of collagen to strengthen the inner structure and increase the holes inside. For different systems, when added amount was 10%, the water absorption of composite sponge dropped from 26.75 times to 15 times, dissolution rate decreased from 3.931% of pure collagen to 1.345 %. The maximum force that composite sponge can withstand increased from 1.31 N to 3N, and compression test showed that the force required in the deformation of 50% increased from 0.482 N to 1.30 N, showing that composite cellulose/collagen sponges can bear more force. For the last, the enzyme-dissolving test showed the degradation situation when the composite sponges were in the simulate situation in vivo.