Characterization of Pacific cod (Gadus macrocephalus) skin collagen and fabrication of collagen sponge as a good biocompatible biomedical material

Acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) were extracted from Pacific cod (Gadus macrocephalus) skin and preliminarily purified via salting-out. Physicochemical properties of both collagen were determined. Amino acid composition analysis indicated that the contents of proline and hydroxyproline were 157 and 159 residues/1000 residues, respectively. And the proline hydroxylation rates were 40.8% for ASC and 41.5% for PSC. Denaturation temperatures (Td) measured with Ubbelohde viscometer were 14.5 degrees C and 16 degrees C, respectively, lower than that of mammals. Moreover, the analysis results of intrinsic viscosity, SDS-PAGE, Ultraviolet (UV) absorption, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) demonstrated that ASC and PSC were triple-helical type I collagens with cc chain composition of (alpha(1))(2)alpha(2). Meanwhile, the scanning electron microscopy (SEM) and the hemolysis assay in vitro indicated that collagen sponge fabricated by freeze-drying technology had uniform and porous structure and good biocompatibility. So it can be applied in biomedical materials field.