Isolation And Characterization Of Collagen From The Skin Of Grass Carp And Construction Of Biological Materials

With the rapid developme nt of tis sue engineering and its keytechnology breakthrough, coll agen become hotspot scholars all around theworld.Nowdays, la nd-based ani mals s uch as cow and pig are the mai nsources of collagen. Howe ver, bovine spongifor m encephalopathy (BSE)and the foot-and-mo uth disease (FMD) crisis have taken place all aroundworld, which have resulted in anxie ty a mong users of collagen andcollagen-derived products fr om land-based ani mals in rec ent years. As aconseque nce, many scientists have been paying attention to alternativecollagen sources. Recently, fish-deri ved collagen has attracted greatnotice as an alternative to animal collagen, because no diseases that cantransmit from fishes to huma ns have been found.There are vast waters and rich fish resources in our country where hasrapidly developed a quaculture. In addi ton, collagen is rich in skin scalesand bone s.Therefore, the developme nt and utilization of fish collagenvalue is gradually by the attention of people. However, compared wit hcollagen from mammals, fish collagen as biological material has lowmechanical strength, the weak of thermal stability and the fast of thedegradation speed which greatly limit the source of fish col lagenapplication in me dical field.On this basis, The freezing rate andultrasonic power on spatial structure and the bioche mical properties ofbiological materials, in order to provide a theoretical basis for the actualproduction, application and s torage of collagen from freshwater fish.The mole cular structure and physicoche mical properties of collagensfrom her bivorous fish and carnivorous fis h were compared. Theacid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) wereextracted from Grass carp and Channa Striatus skin and the compositionsand some physicoche mical properties including enzymatic sensitivity anddenature te mperature of those collagens were investigated and compared.Experi me nt results indicated that all extracted collagens were classifiedas type collagen which comprised t wo the di fferent α c hains.In this paper, we investigated the effe ct of free zing regime on thestructure and bioche mical properties of collagen sponges which weremanufactured by acid-soluble collagen (ASC) from grass carp skins.Freeze-dried collagen sponges showed a networ k structure ofheterogeneous pore s when the collagen gels we re slowly frozen at-40℃(CS-40) or-66℃(CS-66) in cold at mosphere, r espectively. In cont rast, when the cooling process was per for med in l iquid nitrogen (-196℃),s mall and homogeneous pore s were se en in coll agen sponges (CS-196).Compared with CS-40and CS-66, CS-196showed a larg er compre ssivestrength (3770.9±297.0kPa) while it had a higher enzymatic sensitivityand swelling ratio in fluid (P <0.01). Additional, it was observed that allgrass carp collagen sponges did not induce a significant cytotoxic effec tup to3days compar ed with control according to the results of cell culturetest (P>0.05). Mor eover, CS-66section with318.2±57.5um pore sizeshowed better cell growth at5days post-seeding compar ed with controland other sponges (P<0.05). From the results of this pape r, we can dra wthe conclusion that the pore structure of coll agen sponges, whi ch isinfluence d by the freezing regi me during fabrication, can modulate thebioche mic al properties of coll agen sponges.Pepsin-soluble collagen (PSC) as raw materials, were prepared ofCG-0, CG-100, CG–140and CG-180under different ultrasound power (0w,100w,140w a nd180w) in collagen nucleation stage.The turbidityexperiments showed that the in vitro self-assembly capacity graduallyweakened with the increase in ultrasound power. Di fferent collagen gel swere self-asse mbl ed products fiber diameter size as follows:CG-0(102.9±26.3nm)>C G-100(92.8±24.4nm)> CG-140(81.8±18.7nm)>CG-180(79.9±14.9nm)(P<0.05); D-period sizes respectively:66.1±5.6nm、65.0±2.1nm、62.2±3.2nm、62.5±2.0nm. It showed that ultrasonic hadinfluence d on the growth of collagen fiber and the for mation of D-periodsizes on the self-assembly pr ocess. The rheological experimental resultsshowed t hat the viscoelastic modulus and viscosity modulus decreaseswith the increase of the power after ultrasonic treatme nt of collagen gel.