Isolation, characterization and biocompatibility evaluation of collagen from Thunnus tonggol skin

Acid-soluble collagen could be isolated from fish skin using acetic acid. In recent years, much attention has been paid to collagen from marine sources, mainly arising from the fact that there is no risk of contagious diseases. Moreover, by processing the fish, significant amounts of waste materials are produced which can be considered as a substitute for these collagen sources. Thunnus tonggol skin collagen was extracted by acid and base methods and evaluated by SDS-PAGE, FTIR and UV spectrophotometry and amino acid composition analysis. To determine biocompatibility, growth, and proliferation of extracted collagen, MTT and H&E staining methods were used. The results, predicated on SDS-PAGE and amino acid analysis, demonstrated that the fish skin collagen was of type I consisting of two α chains (α1 and α2) with molecular weight of 135 kDa and mass fraction of β. FTIR analysis also revealed helical compositions of both collagens, and UV spectrophotometry in T. tonggol skin collagen indicated a maximum absorption of 235 nm. The amount of collagen extracted from T. tonggol skin turned out to be 17.3% dry weight. Analysis of extracted collagen amino acids from the mentioned fish showed that glycine was the predominant amino acid. Human fibroblast culture presented a superior growth and good biocompatibility on extracted collagen. So, this type of collagen could be used in tissue engineering as a proper scaffold.