Characterization of three-spot seahorse (Hippocampus trimaculatus) skin collagen and its fibrillar gel reinforced by EDC: A comparative study

In current study, three-spot seahorse ( Hippocampus trimaculatus ) skin collagen (SC) was extracted for the first time, and its physicochemical properties were characterized. Nile tilapia-skin collagen (TC) and pig-skin collagen (PC) were used to the references. The yields of SC and TC were 40.41 ± 1.23 and 52.6 ± 0.97% (dry weight), respectively. The SDS-PAGE and FTIR confirmed that SC, TC, and PC were preliminarily identified as type I collagen with triple helical structure. The denaturation temperatures of SC, TC, and PC were 35.12, 38.66, and 42.56°C, respectively. Gel-forming studies indicated SC exhibited higher capability than TC and PC under the effect of NaCl. After cross-linking by 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC), SC showed a significant increase in thermal stability and mechanical strength, and electron microscopic observation corroborated this phenomenon. Therefore, the isolated collagen from three-spot seahorse skin can be used in food packaging and biomaterials as alternatives to mammalian collagen. Practical applications In this study, we evaluated a new source of skin collagen from three-spot seahorse which has been large-scale artificially cultured in recent years. The finding of this study demonstrate that SC exhibited higher gel-forming capability under the effect of NaCl, which suggest that it may be used in photographic film, sausage casings, and food additive as alternatives to mammalian collagen. Furthermore, thermal stability and mechanical strength of SC gel have a significant increase after cross-linking by EDC, so it can be further used for biomaterials, such as food packaging, drug delivery, tissue engineering constructs, and wound dressing systems.