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Stephen Mann - One of the best experts on this subject based on the ideXlab platform.
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physical properties of type i collagen extracted from fish scales of Pagrus Major and oreochromis niloticas
International Journal of Biological Macromolecules, 2003Co-Authors: Toshiyuki Ikoma, Hisatoshi Kobayashi, Junzo Tanaka, Dominic M Walsh, Stephen MannAbstract:Abstract Type I collagens were extracted from fish scales of Pagrus Major and Oreochromis niloticas as a possible underutilized resource for medical materials. The fish scales were demineralized with EDTA and digested by pepsin. The resultant type I collagens contained more than 33.6% of glycine as the most abundant amino acid. The denaturation temperatures of the collagens from P. Major and O. niloticas were 303 and 308 K, respectively, both of which were relatively lower than that of porcine dermis collagen (314 K). CD spectra indicated that the denaturation temperatures were dependent on the amount of hydroxyproline, rather than proline residues. Raman spectra also indicated that the relative intensities of Raman lines at 879 and 855 cm −1 assigned to Hyp and Pro rings were changed due to the contents of the imino acids. Significantly, the content of sulphur-containing methionine was higher in the fish scales than in porcine dermis. The enthalpy and entropy estimated from thermal analyses could be correlated to amino acid sequences (Gly-Pro-Hyp) of type I collagens and the number of methionine amino acid residues.
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microstructure mechanical and biomimetic properties of fish scales from Pagrus Major
Journal of Structural Biology, 2003Co-Authors: Toshiyuki Ikoma, Dominic Walsh, Hisatoshi Kobayashi, Junzo Tanaka, Stephen MannAbstract:Abstract The fish scale of Pagrus Major has an orthogonal plywood structure of stratified lamellae, 1–2 μm in thickness, consisting of closely packed 70- to 80-nm-diameter collagen fibers. X-ray diffraction, energy-dispersive X-ray analysis, and infrared spectroscopy indicate that the mineral phase in the scale is calcium-deficient hydroxyapatite containing a small amount of sodium and magnesium ions, as well as carbonate anions in phosphate sites of the apatite lattice. The tensile strength of the scale is high (∼90 MPa) because of the hierarchically ordered structure of mineralized collagen fibers. Mechanical failure occurs by sliding of the lamellae and associated pulling out and fracture of the collagen fibers. In contrast, demineralized scales have significantly lower tensile strength (36 MPa), indicating that interactions between the apatite crystals and collagen fibers are of fundamental importance in determining the mechanical properties. Thermal treatment of fish scales to remove the organic components produces remarkable inorganic replicas of the native orthogonal plywood structure of the fibrillary plate. The biomimetic replica produced by heating to 873 K consists of stratified porous lamellae of c -axis-aligned apatite crystals that are long, narrow plates, 0.5–0.6 μm in length and 0.1–0.2 μm in width. The textured inorganic material remains intact when heated to 1473 K, although the size of the constituent crystals increases as a result of thermal sintering.
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Physical properties of type I collagen extracted from fish scales of Pagrus Major and Oreochromis niloticas
International Journal of Biological Macromolecules, 2003Co-Authors: Toshiyuki Ikoma, Dominic Walsh, Hisatoshi Kobayashi, Junzo Tanaka, Stephen MannAbstract:Type I collagens were extracted from fish scales of Pagrus Major and Oreochromis niloticas as a possible underutilized resource for medical materials. The fish scales were demineralized with EDTA and digested by pepsin. The resultant type I collagens contained more than 33.6% of glycine as the most abundant amino acid. The denaturation temperatures of the collagens from P. Major and O. niloticas were 303 and 308K, respectively, both of which were relatively lower than that of porcine dermis collagen (314K). CD spectra indicated that the denaturation temperatures were dependent on the amount of hydroxyproline, rather than proline residues. Raman spectra also indicated that the relative intensities of Raman lines at 879 and 855cm-1 assigned to Hyp and Pro rings were changed due to the contents of the imino acids. Significantly, the content of sulphur-containing methionine was higher in the fish scales than in porcine dermis. The enthalpy and entropy estimated from thermal analyses could be correlated to amino acid sequences (Gly-Pro-Hyp) of type I collagens and the number of methionine amino acid residues. ?? 2003 Elsevier B.V. All rights reserved.
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Microstructure, mechanical, and biomimetic properties of fish scales from Pagrus Major
Journal of Structural Biology, 2003Co-Authors: Toshiyuki Ikoma, Dominic Walsh, Hisatoshi Kobayashi, Junzo Tanaka, Stephen MannAbstract:The fish scale of Pagrus Major has an orthogonal plywood structure of stratified lamellae, 1-2??m in thickness, consisting of closely packed 70- to 80-nm-diameter collagen fibers. X-ray diffraction, energy-dispersive X-ray analysis, and infrared spectroscopy indicate that the mineral phase in the scale is calcium-deficient hydroxyapatite containing a small amount of sodium and magnesium ions, as well as carbonate anions in phosphate sites of the apatite lattice. The tensile strength of the scale is high (???90MPa) because of the hierarchically ordered structure of mineralized collagen fibers. Mechanical failure occurs by sliding of the lamellae and associated pulling out and fracture of the collagen fibers. In contrast, demineralized scales have significantly lower tensile strength (36MPa), indicating that interactions between the apatite crystals and collagen fibers are of fundamental importance in determining the mechanical properties. Thermal treatment of fish scales to remove the organic components produces remarkable inorganic replicas of the native orthogonal plywood structure of the fibrillary plate. The biomimetic replica produced by heating to 873K consists of stratified porous lamellae of c-axis-aligned apatite crystals that are long, narrow plates, 0.5-0.6??m in length and 0.1-0.2??m in width. The textured inorganic material remains intact when heated to 1473K, although the size of the constituent crystals increases as a result of thermal sintering. ?? 2003 Elsevier Science (USA). All rights reserved.
Toshiyuki Ikoma - One of the best experts on this subject based on the ideXlab platform.
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physical properties of type i collagen extracted from fish scales of Pagrus Major and oreochromis niloticas
International Journal of Biological Macromolecules, 2003Co-Authors: Toshiyuki Ikoma, Hisatoshi Kobayashi, Junzo Tanaka, Dominic M Walsh, Stephen MannAbstract:Abstract Type I collagens were extracted from fish scales of Pagrus Major and Oreochromis niloticas as a possible underutilized resource for medical materials. The fish scales were demineralized with EDTA and digested by pepsin. The resultant type I collagens contained more than 33.6% of glycine as the most abundant amino acid. The denaturation temperatures of the collagens from P. Major and O. niloticas were 303 and 308 K, respectively, both of which were relatively lower than that of porcine dermis collagen (314 K). CD spectra indicated that the denaturation temperatures were dependent on the amount of hydroxyproline, rather than proline residues. Raman spectra also indicated that the relative intensities of Raman lines at 879 and 855 cm −1 assigned to Hyp and Pro rings were changed due to the contents of the imino acids. Significantly, the content of sulphur-containing methionine was higher in the fish scales than in porcine dermis. The enthalpy and entropy estimated from thermal analyses could be correlated to amino acid sequences (Gly-Pro-Hyp) of type I collagens and the number of methionine amino acid residues.
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microstructure mechanical and biomimetic properties of fish scales from Pagrus Major
Journal of Structural Biology, 2003Co-Authors: Toshiyuki Ikoma, Dominic Walsh, Hisatoshi Kobayashi, Junzo Tanaka, Stephen MannAbstract:Abstract The fish scale of Pagrus Major has an orthogonal plywood structure of stratified lamellae, 1–2 μm in thickness, consisting of closely packed 70- to 80-nm-diameter collagen fibers. X-ray diffraction, energy-dispersive X-ray analysis, and infrared spectroscopy indicate that the mineral phase in the scale is calcium-deficient hydroxyapatite containing a small amount of sodium and magnesium ions, as well as carbonate anions in phosphate sites of the apatite lattice. The tensile strength of the scale is high (∼90 MPa) because of the hierarchically ordered structure of mineralized collagen fibers. Mechanical failure occurs by sliding of the lamellae and associated pulling out and fracture of the collagen fibers. In contrast, demineralized scales have significantly lower tensile strength (36 MPa), indicating that interactions between the apatite crystals and collagen fibers are of fundamental importance in determining the mechanical properties. Thermal treatment of fish scales to remove the organic components produces remarkable inorganic replicas of the native orthogonal plywood structure of the fibrillary plate. The biomimetic replica produced by heating to 873 K consists of stratified porous lamellae of c -axis-aligned apatite crystals that are long, narrow plates, 0.5–0.6 μm in length and 0.1–0.2 μm in width. The textured inorganic material remains intact when heated to 1473 K, although the size of the constituent crystals increases as a result of thermal sintering.
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Physical properties of type I collagen extracted from fish scales of Pagrus Major and Oreochromis niloticas
International Journal of Biological Macromolecules, 2003Co-Authors: Toshiyuki Ikoma, Dominic Walsh, Hisatoshi Kobayashi, Junzo Tanaka, Stephen MannAbstract:Type I collagens were extracted from fish scales of Pagrus Major and Oreochromis niloticas as a possible underutilized resource for medical materials. The fish scales were demineralized with EDTA and digested by pepsin. The resultant type I collagens contained more than 33.6% of glycine as the most abundant amino acid. The denaturation temperatures of the collagens from P. Major and O. niloticas were 303 and 308K, respectively, both of which were relatively lower than that of porcine dermis collagen (314K). CD spectra indicated that the denaturation temperatures were dependent on the amount of hydroxyproline, rather than proline residues. Raman spectra also indicated that the relative intensities of Raman lines at 879 and 855cm-1 assigned to Hyp and Pro rings were changed due to the contents of the imino acids. Significantly, the content of sulphur-containing methionine was higher in the fish scales than in porcine dermis. The enthalpy and entropy estimated from thermal analyses could be correlated to amino acid sequences (Gly-Pro-Hyp) of type I collagens and the number of methionine amino acid residues. ?? 2003 Elsevier B.V. All rights reserved.
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Microstructure, mechanical, and biomimetic properties of fish scales from Pagrus Major
Journal of Structural Biology, 2003Co-Authors: Toshiyuki Ikoma, Dominic Walsh, Hisatoshi Kobayashi, Junzo Tanaka, Stephen MannAbstract:The fish scale of Pagrus Major has an orthogonal plywood structure of stratified lamellae, 1-2??m in thickness, consisting of closely packed 70- to 80-nm-diameter collagen fibers. X-ray diffraction, energy-dispersive X-ray analysis, and infrared spectroscopy indicate that the mineral phase in the scale is calcium-deficient hydroxyapatite containing a small amount of sodium and magnesium ions, as well as carbonate anions in phosphate sites of the apatite lattice. The tensile strength of the scale is high (???90MPa) because of the hierarchically ordered structure of mineralized collagen fibers. Mechanical failure occurs by sliding of the lamellae and associated pulling out and fracture of the collagen fibers. In contrast, demineralized scales have significantly lower tensile strength (36MPa), indicating that interactions between the apatite crystals and collagen fibers are of fundamental importance in determining the mechanical properties. Thermal treatment of fish scales to remove the organic components produces remarkable inorganic replicas of the native orthogonal plywood structure of the fibrillary plate. The biomimetic replica produced by heating to 873K consists of stratified porous lamellae of c-axis-aligned apatite crystals that are long, narrow plates, 0.5-0.6??m in length and 0.1-0.2??m in width. The textured inorganic material remains intact when heated to 1473K, although the size of the constituent crystals increases as a result of thermal sintering. ?? 2003 Elsevier Science (USA). All rights reserved.
Hidemi Kumai - One of the best experts on this subject based on the ideXlab platform.
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effect of photoperiod manipulation on the growth performance and stress response of juvenile red sea bream Pagrus Major
Aquaculture, 2006Co-Authors: Amal Biswas, Kenzi Takii, Manabu Seoka, Yoshimasa Tanaka, Hidemi KumaiAbstract:Abstract Juvenile of red sea bream ( Pagrus Major , body weight 1∼30 g) were reared under four photoperiods (6L:6D, 12L:12D, 16L:8D and 24L:0D) with constant light intensity 1500 lx on the water surface to investigate their growth performance and stress response. Fish were fed a commercial diet to apparent satiation for 8 weeks of the experiment. Significantly higher weight gain and specific growth rates (SGR) were observed in fish exposed to a 24L:0D photoperiod followed by 16L:8D, 6L:6D and 12L:12D photoperiods ( P P
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hypoxic conditions induce centrum defects in red sea bream Pagrus Major temminck and schlegel
Aquaculture Research, 2006Co-Authors: Yoshifumi Sawada, Keitaro Kato, Manabu Hattori, Yasuaki Takagi, Tokihiko Okada, Michio Kurata, Naoko Sudo, Hidemi KumaiAbstract:A previous study elucidated that an extreme hypoxia during somitogenesis induced the most frequent skeletal malformation centrum defects in red sea bream (RSB), Pagrus Major. In this study, details of the hypoxic conditions to induce them in RSB, dissolved oxygen (DO) concentration and exposure time to hypoxia, were investigated. Fertilized eggs were exposed to seawater of six DO concentrations (0%, 10%, 25%, 50%, 75% and 100% of saturation) for seven different periods (5, 10, 30, 60, 120, 240 and 360 min) during somitogenesis. Somitic disturbances in newly hatched larvae were induced by exposure to 0% and 10% DO concentration for 10 and 120 min and longer respectively. Rearing eggs exposed to hypoxic condition of 10% DO for 240 min for 40 days post-hatch showed that the location and the frequency of somitic disturbances in larvae and centrum defects in juveniles were significantly correlated (P<0.01). Dissolved oxygen concentration of the interstitial water in the egg high density layer formed at the water surface in a stationary state abruptly decreased to 3.7% within 7 min. Centrum defect induction by exposure of eggs to extreme low DO concentrations for a short period, which is the probable situation in the practical juvenile production, suggests that careful maintenance of DO concentration is important in the incubating water of fertilized eggs during egg sorting and transportation, where eggs are made into a pile and undergo hypoxia, for the prevention of centrum defects.
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photoperiod influences the growth food intake feed efficiency and digestibility of red sea bream Pagrus Major
Aquaculture, 2005Co-Authors: Amal Biswas, Manabu Seoka, Yuya Inoue, Kenji Takii, Hidemi KumaiAbstract:Abstract Two consecutive trials were conducted to investigate the effects of photoperiod manipulation on growth rate, food intake and feed conversion efficiency (Trial 1), and the digestibility of nutrients and energy (Trial 2) in red sea bream, Pagrus Major (body weight 19–120 g). Fish were exposed to four photoperiods (6L:6D, 12L:12D, 16L:8D and 24L:0D) with light intensity 1500 lx on the water surface. The fish were fed with a commercial diet to apparent satiation. In Trial 2, 0.5% chromic oxide (Cr2O3) was used as an inert marker. Significantly higher weight gain and specific growth rates were observed in fish exposed to a 24L:0D photoperiod followed by 16L:8D, 6L:6D and 12L:12D photoperiods (P
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oxygen deficiency during somitogenesis causes centrum defects in red sea bream Pagrus Major temminck et schlegel
Aquaculture Research, 2004Co-Authors: Manabu Hattori, Keitaro Kato, Shinji Yamamoto, Yoshifumi Sawada, Michio Kurata, Hidemi KumaiAbstract:Vertebral deformities in red sea bream, Pagrus Major, remain serious obstacles to the improvement of seedling quality for its aquaculture. However, the causalities of the deformities remain unclear and prevention methods have not yet been established. In this paper, oxygen deficiency during somitogenesis was demonstrated to cause centrum defects (formerly called fused vertebrae in many cases), which are the Major vertebral deformity in cultured red sea bream. An induction experiment of centrum defects was conducted by placing fertilized red sea bream eggs under low dissolved oxygen conditions (10.3–16.6%). The low oxygen treatment was carried out for five different developmental stages of embryo: two-cell stage to blastula stage; gastrula stage; three to 10 somites stage; 11–17 somites stage and 18–24 somites stage. Oxygen deficiency during somitogenesis induced a high incidence of centrum defects. In contrast, it hardly induced centrum defects during the other stages. The dissolved oxygen concentration in the rearing water should be carefully regulated for fertilized eggs, especially during somitogenesis to reduce the incidence of vertebral deformities in the red sea bream.
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vertebral deformities in cultured red sea bream Pagrus Major temminck and schlegel
Aquaculture Research, 2003Co-Authors: Manabu Hattori, Yoshifumi Sawada, Yasuaki Takagi, R Suzuki, Tokihiko Okada, Hidemi KumaiAbstract:Vertebral deformities were investigated in cultured red sea bream, Pagrus Major. In the field, deformities in seedlings were categorized and their incidence was calculated. In the laboratory, the symptoms of Major vertebral deformities were examined morphologically using radiographs and by making transparent skeletal specimens. The internal structure of deformed vertebrae was examined histologically. The shortened body condition had the highest incidence (0.9–8.3%) of all deformities in the seedlings. In individuals with the shortened body condition, the ratio of trunk and caudal part length to body height was smaller. These fish had skeletal anomalies in the vertebrae, mainly centrum defects (64.3%) or undersized centrums (25.2%). The specimens with centrum defects had a characteristic anomaly in the vertebrae, with plural pairs of neural and haemal spines on a single centrum. This anomaly was frequently observed in the posterior abdominal vertebrae. The internal skeletal structure of such abnormal centrums was basically the same as that of normal centrums. In all the specimens with undersized centrums, both the centrum length and diameter were shorter than normal except for the first and second centrum, and urostyle.
Hisatoshi Kobayashi - One of the best experts on this subject based on the ideXlab platform.
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physical properties of type i collagen extracted from fish scales of Pagrus Major and oreochromis niloticas
International Journal of Biological Macromolecules, 2003Co-Authors: Toshiyuki Ikoma, Hisatoshi Kobayashi, Junzo Tanaka, Dominic M Walsh, Stephen MannAbstract:Abstract Type I collagens were extracted from fish scales of Pagrus Major and Oreochromis niloticas as a possible underutilized resource for medical materials. The fish scales were demineralized with EDTA and digested by pepsin. The resultant type I collagens contained more than 33.6% of glycine as the most abundant amino acid. The denaturation temperatures of the collagens from P. Major and O. niloticas were 303 and 308 K, respectively, both of which were relatively lower than that of porcine dermis collagen (314 K). CD spectra indicated that the denaturation temperatures were dependent on the amount of hydroxyproline, rather than proline residues. Raman spectra also indicated that the relative intensities of Raman lines at 879 and 855 cm −1 assigned to Hyp and Pro rings were changed due to the contents of the imino acids. Significantly, the content of sulphur-containing methionine was higher in the fish scales than in porcine dermis. The enthalpy and entropy estimated from thermal analyses could be correlated to amino acid sequences (Gly-Pro-Hyp) of type I collagens and the number of methionine amino acid residues.
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microstructure mechanical and biomimetic properties of fish scales from Pagrus Major
Journal of Structural Biology, 2003Co-Authors: Toshiyuki Ikoma, Dominic Walsh, Hisatoshi Kobayashi, Junzo Tanaka, Stephen MannAbstract:Abstract The fish scale of Pagrus Major has an orthogonal plywood structure of stratified lamellae, 1–2 μm in thickness, consisting of closely packed 70- to 80-nm-diameter collagen fibers. X-ray diffraction, energy-dispersive X-ray analysis, and infrared spectroscopy indicate that the mineral phase in the scale is calcium-deficient hydroxyapatite containing a small amount of sodium and magnesium ions, as well as carbonate anions in phosphate sites of the apatite lattice. The tensile strength of the scale is high (∼90 MPa) because of the hierarchically ordered structure of mineralized collagen fibers. Mechanical failure occurs by sliding of the lamellae and associated pulling out and fracture of the collagen fibers. In contrast, demineralized scales have significantly lower tensile strength (36 MPa), indicating that interactions between the apatite crystals and collagen fibers are of fundamental importance in determining the mechanical properties. Thermal treatment of fish scales to remove the organic components produces remarkable inorganic replicas of the native orthogonal plywood structure of the fibrillary plate. The biomimetic replica produced by heating to 873 K consists of stratified porous lamellae of c -axis-aligned apatite crystals that are long, narrow plates, 0.5–0.6 μm in length and 0.1–0.2 μm in width. The textured inorganic material remains intact when heated to 1473 K, although the size of the constituent crystals increases as a result of thermal sintering.
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Physical properties of type I collagen extracted from fish scales of Pagrus Major and Oreochromis niloticas
International Journal of Biological Macromolecules, 2003Co-Authors: Toshiyuki Ikoma, Dominic Walsh, Hisatoshi Kobayashi, Junzo Tanaka, Stephen MannAbstract:Type I collagens were extracted from fish scales of Pagrus Major and Oreochromis niloticas as a possible underutilized resource for medical materials. The fish scales were demineralized with EDTA and digested by pepsin. The resultant type I collagens contained more than 33.6% of glycine as the most abundant amino acid. The denaturation temperatures of the collagens from P. Major and O. niloticas were 303 and 308K, respectively, both of which were relatively lower than that of porcine dermis collagen (314K). CD spectra indicated that the denaturation temperatures were dependent on the amount of hydroxyproline, rather than proline residues. Raman spectra also indicated that the relative intensities of Raman lines at 879 and 855cm-1 assigned to Hyp and Pro rings were changed due to the contents of the imino acids. Significantly, the content of sulphur-containing methionine was higher in the fish scales than in porcine dermis. The enthalpy and entropy estimated from thermal analyses could be correlated to amino acid sequences (Gly-Pro-Hyp) of type I collagens and the number of methionine amino acid residues. ?? 2003 Elsevier B.V. All rights reserved.
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Microstructure, mechanical, and biomimetic properties of fish scales from Pagrus Major
Journal of Structural Biology, 2003Co-Authors: Toshiyuki Ikoma, Dominic Walsh, Hisatoshi Kobayashi, Junzo Tanaka, Stephen MannAbstract:The fish scale of Pagrus Major has an orthogonal plywood structure of stratified lamellae, 1-2??m in thickness, consisting of closely packed 70- to 80-nm-diameter collagen fibers. X-ray diffraction, energy-dispersive X-ray analysis, and infrared spectroscopy indicate that the mineral phase in the scale is calcium-deficient hydroxyapatite containing a small amount of sodium and magnesium ions, as well as carbonate anions in phosphate sites of the apatite lattice. The tensile strength of the scale is high (???90MPa) because of the hierarchically ordered structure of mineralized collagen fibers. Mechanical failure occurs by sliding of the lamellae and associated pulling out and fracture of the collagen fibers. In contrast, demineralized scales have significantly lower tensile strength (36MPa), indicating that interactions between the apatite crystals and collagen fibers are of fundamental importance in determining the mechanical properties. Thermal treatment of fish scales to remove the organic components produces remarkable inorganic replicas of the native orthogonal plywood structure of the fibrillary plate. The biomimetic replica produced by heating to 873K consists of stratified porous lamellae of c-axis-aligned apatite crystals that are long, narrow plates, 0.5-0.6??m in length and 0.1-0.2??m in width. The textured inorganic material remains intact when heated to 1473K, although the size of the constituent crystals increases as a result of thermal sintering. ?? 2003 Elsevier Science (USA). All rights reserved.
Junzo Tanaka - One of the best experts on this subject based on the ideXlab platform.
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physical properties of type i collagen extracted from fish scales of Pagrus Major and oreochromis niloticas
International Journal of Biological Macromolecules, 2003Co-Authors: Toshiyuki Ikoma, Hisatoshi Kobayashi, Junzo Tanaka, Dominic M Walsh, Stephen MannAbstract:Abstract Type I collagens were extracted from fish scales of Pagrus Major and Oreochromis niloticas as a possible underutilized resource for medical materials. The fish scales were demineralized with EDTA and digested by pepsin. The resultant type I collagens contained more than 33.6% of glycine as the most abundant amino acid. The denaturation temperatures of the collagens from P. Major and O. niloticas were 303 and 308 K, respectively, both of which were relatively lower than that of porcine dermis collagen (314 K). CD spectra indicated that the denaturation temperatures were dependent on the amount of hydroxyproline, rather than proline residues. Raman spectra also indicated that the relative intensities of Raman lines at 879 and 855 cm −1 assigned to Hyp and Pro rings were changed due to the contents of the imino acids. Significantly, the content of sulphur-containing methionine was higher in the fish scales than in porcine dermis. The enthalpy and entropy estimated from thermal analyses could be correlated to amino acid sequences (Gly-Pro-Hyp) of type I collagens and the number of methionine amino acid residues.
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microstructure mechanical and biomimetic properties of fish scales from Pagrus Major
Journal of Structural Biology, 2003Co-Authors: Toshiyuki Ikoma, Dominic Walsh, Hisatoshi Kobayashi, Junzo Tanaka, Stephen MannAbstract:Abstract The fish scale of Pagrus Major has an orthogonal plywood structure of stratified lamellae, 1–2 μm in thickness, consisting of closely packed 70- to 80-nm-diameter collagen fibers. X-ray diffraction, energy-dispersive X-ray analysis, and infrared spectroscopy indicate that the mineral phase in the scale is calcium-deficient hydroxyapatite containing a small amount of sodium and magnesium ions, as well as carbonate anions in phosphate sites of the apatite lattice. The tensile strength of the scale is high (∼90 MPa) because of the hierarchically ordered structure of mineralized collagen fibers. Mechanical failure occurs by sliding of the lamellae and associated pulling out and fracture of the collagen fibers. In contrast, demineralized scales have significantly lower tensile strength (36 MPa), indicating that interactions between the apatite crystals and collagen fibers are of fundamental importance in determining the mechanical properties. Thermal treatment of fish scales to remove the organic components produces remarkable inorganic replicas of the native orthogonal plywood structure of the fibrillary plate. The biomimetic replica produced by heating to 873 K consists of stratified porous lamellae of c -axis-aligned apatite crystals that are long, narrow plates, 0.5–0.6 μm in length and 0.1–0.2 μm in width. The textured inorganic material remains intact when heated to 1473 K, although the size of the constituent crystals increases as a result of thermal sintering.
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Physical properties of type I collagen extracted from fish scales of Pagrus Major and Oreochromis niloticas
International Journal of Biological Macromolecules, 2003Co-Authors: Toshiyuki Ikoma, Dominic Walsh, Hisatoshi Kobayashi, Junzo Tanaka, Stephen MannAbstract:Type I collagens were extracted from fish scales of Pagrus Major and Oreochromis niloticas as a possible underutilized resource for medical materials. The fish scales were demineralized with EDTA and digested by pepsin. The resultant type I collagens contained more than 33.6% of glycine as the most abundant amino acid. The denaturation temperatures of the collagens from P. Major and O. niloticas were 303 and 308K, respectively, both of which were relatively lower than that of porcine dermis collagen (314K). CD spectra indicated that the denaturation temperatures were dependent on the amount of hydroxyproline, rather than proline residues. Raman spectra also indicated that the relative intensities of Raman lines at 879 and 855cm-1 assigned to Hyp and Pro rings were changed due to the contents of the imino acids. Significantly, the content of sulphur-containing methionine was higher in the fish scales than in porcine dermis. The enthalpy and entropy estimated from thermal analyses could be correlated to amino acid sequences (Gly-Pro-Hyp) of type I collagens and the number of methionine amino acid residues. ?? 2003 Elsevier B.V. All rights reserved.
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Microstructure, mechanical, and biomimetic properties of fish scales from Pagrus Major
Journal of Structural Biology, 2003Co-Authors: Toshiyuki Ikoma, Dominic Walsh, Hisatoshi Kobayashi, Junzo Tanaka, Stephen MannAbstract:The fish scale of Pagrus Major has an orthogonal plywood structure of stratified lamellae, 1-2??m in thickness, consisting of closely packed 70- to 80-nm-diameter collagen fibers. X-ray diffraction, energy-dispersive X-ray analysis, and infrared spectroscopy indicate that the mineral phase in the scale is calcium-deficient hydroxyapatite containing a small amount of sodium and magnesium ions, as well as carbonate anions in phosphate sites of the apatite lattice. The tensile strength of the scale is high (???90MPa) because of the hierarchically ordered structure of mineralized collagen fibers. Mechanical failure occurs by sliding of the lamellae and associated pulling out and fracture of the collagen fibers. In contrast, demineralized scales have significantly lower tensile strength (36MPa), indicating that interactions between the apatite crystals and collagen fibers are of fundamental importance in determining the mechanical properties. Thermal treatment of fish scales to remove the organic components produces remarkable inorganic replicas of the native orthogonal plywood structure of the fibrillary plate. The biomimetic replica produced by heating to 873K consists of stratified porous lamellae of c-axis-aligned apatite crystals that are long, narrow plates, 0.5-0.6??m in length and 0.1-0.2??m in width. The textured inorganic material remains intact when heated to 1473K, although the size of the constituent crystals increases as a result of thermal sintering. ?? 2003 Elsevier Science (USA). All rights reserved.
