Study On Physicochemical Characteristics Of Collagen And Preparation Of Composites From The Skin Of Channel Catfish

In this paper, The acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) were extracted from skin of channel catfish by the methods of acid and acid-pepsin, and their physical and chemical characterization were analysed. The two kinds of collagen were processed into collagen composites, and the cell biocompatibility was preliminary evaluation. The main results were as following:1. The extracted and physicochemical characterization of collagen(1) By the methods of acid and acid-pepsin, the ASC and PSC were extracted from the skin of channel catfish and the content of hydroxyproline was determined. The results indicated that the ASC had high purity of93.11%and PSC of93.46%. High purity of collagen was harvest used the methods of acid and acid-pepsin.(2) The analysis of UV spectra, fourier transform infrared (FTIR) spectra and SDS-PAGE of ASC and PSC showed that the two kinds of collagen were characterized as type Ⅰ and almost similar with whole triple-helical structure.(3) Transition temperature and the analysis of amino acid of ASC and PSC indicated that the collagen extracted from channel catfish contained large amount of glycine. Besides, the transition temperature and the content of hydroxyproline were inferior to collagen from mammal. There were slight differences between the ASC and PSC in transition temperature and amino acid content.2. The preparation and physical and chemical characterization of collagen composite(1) The collagen composite was preparation by in situ synthesis and cross-lined in0.25%glutaraldehyde for24h.(2) The analysis of XRD of collagen composite indicated that the hydroxyapatite in the composite was poorly crystallized. The composites of low crystallinity were in favour of biodegradability in living creature and cell adhesion and proliferation on composites.(3) SEM images and porosity measurement of composites indicated the composites had high porosity more than90%, and had regular shape. The proper aperture was benefiticial to cell adhesion. The proportion of collagen and hydroxyapatite is50:50, the aperture was generally40～100μm, had better connectivity between the hole in favor of waste drainage, exchange of nutrient. The proportion of collagen and hydroxyapatite is30:70, the aperture was generally20μm, and pore wall became thick.3. The cytocompatibility of different ratio of collagen composites(1) MC3T3cultured in different composites extract, the result indicated when incubation time was prolonged, there were signal transduction and cell mitosis. And after7days of cultivation, the cell proliferation sharp increased and the cells became confluence. Lower cell viability was found with the composite with30%ASC.(2) Cell proliferation was monitored by the MTT test. When incubation time was prolonged, the cell proliferation and cell viability increased, and there were significantly differences between different composites. The highest cell viability was found with the composite with50%ASC and the lowest with30%.