Based On The Multi-stage Countercurrent Extraction Of Collagen Preparation Technology And Application

Collagen was widely used in biomedical and pharmaceutical application because of the unique physical and chemical properties. The traditional production methods of collagen had some defects, such as uncontrollable degradation, wide range of molecular weight distribution, low production yield and imperfect extraction technology. In this study, we have researched the technology of multi-stage counter-current solid-liquid extraction to produce collagen based on the thermal stability of collagen, explored the preparation and application of collagen-based biological materials and studied the feasibility of enzymatic reaction and membrane separation coupling technology for the collagen peptides preparation. The main conclusions are as follows:1. The relationship between the thermal stability of collagen and hydroxyproline content were studied by Different age groups of male and female BN rats(Brown Norway Rat/CriBR). The results indicated that hydroxylproline content in skin and extracted collagen increased with age and stabilized at maturity. Before maturity, the collagen dissolution rate of the female rats was higher than that of male rats. After maturity, the collagen dissolution rate of the male rats was higher than that of female rats. Hydroxyproline content and molecular weight of collagen also had a huge effect on the stability. The stablility improved with the hydroxyproline content increased. The molecular weight higher, the triple helix structure more complete and the collagen more stable.2. It was investigated that the feasibility of multi-stage counter-current solid-liquid extraction technology for collagen preparation. The process had been optimized for different sources of raw materials. After optimization the solid-liquid ratio of water and tilapia was1:8g/mL. The results indicated that the water consumption of new technology reduced by20%compared with the traditional collagen extraction process and the collagen yield reached up to95%. The collagen extracted by multi-stage counter-current solid-liquid extraction technology had lighter color, higher concentration, lower random degradation, narrower range of molecular weight distribution and more high molecular weight content than that by traditional extraction. Moreover, new process had advantages of short extract cycle, high degree of automation and continuity.3. The preparation and application of collagen sponge and composite collagen sponge were studied by the collagen extracted from fish scale. It was explored that the effect of collagen concentration, crosslinker concentration and freeze-drying process on the properties of collagen sponge. The result revealed that the collagen sponge had white or pale yellow color. There were some open pores on the smooth surface, which was100-250um. The collagen sponge fiber mainly arranged in mess and a few in linear order. As drug carrier, rb-bFGF(Recombinant Bovine Basic Fibroblast Growth Factor) collagen sponge were put in the simulated body fluid. It was found that the rb-bFGF could be detected in lh and3h and saturated in5h. The nanocrystalline silver collagen sponge, whose surface evenly distributed with20-50nm nano-silver particles, had different degrees of inhibitory effects on bacteria of G+and G", and the inhibitory effect on G"(E.coli) was higher than that on G+in the same concentration of bacteria.4. The enzymatic reaction and membrane separation coupling technology was used to produce collagen peptides. The process parameters such as temperature, cut flow rate and amount of enzyme were studyed and optimized. The results indicated that the molecular weight of collagen peptides which were filtered through the ultrafiltration membrane were uniform, about60kDa. It proved that enzymatic reactions and membrane separation coupling technology for the collagen peptides preparation had advantages of uniform molecular weight and controllable. The collagen peptides could be used as the blocking agent in the preparation of immune diagnostic kits.It could conclude that the thermal stability of collagen was related to its molecular weight and hydroxyproline content. The higher molecular weight and hydroxyproline content, the collagen more stable. Based on the stability studies, the multi-stage counter-current solid-liquid extraction technology was used to extract different biological sources of collagen. The production had a narrow molecular weight range and a high concentration. The process was continuous and automatic. Collagen sponge that prepared with collagen solution had pore size of100-250μm, arranged mainly in mesh and could be used as drug carrier. The molecular weight of collagen polypeptide by enzymatic-membrane separation coupling technology was homogeneous (60kDa), which used as the blocking agent in immune diagnostic kits with better effect than casein.