Extraction, characterization, and biomedical applications of type I collagen derived from fish scales and skin by-products

Abstract

Fish processing generates substantial quantities of scales and skin by-products that represent underutilized sources of high-quality collagen suitable for biomedical applications. This research developed optimized extraction protocols for type I collagen from fish by-products and characterized the resulting materials for tissue engineering applications. Scales and skin from tilapia, salmon, cod, and tuna were obtained from commercial fish processing facilities in Japan. Acid-soluble and pepsin-soluble collagen fractions were extracted using established procedures modified for improved yield and purity at the Department of Biomaterials Science, Tokyo Institute of Applied Sciences between April 2022 and September 2023. Extraction yields ranged from 18.7% to 23.4% depending on species and tissue source, with purity exceeding 91% as assessed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Differential scanning calorimetry revealed denaturation temperatures between 28.4 and 34.7 degrees Celsius, lower than mammalian collagen but adequate for ambient temperature applications. Cell culture experiments demonstrated excellent biocompatibility with human fibroblasts showing 94.2% viability on fish collagen scaffolds. The collagen supported cell adhesion, proliferation, and extracellular matrix deposition comparable to bovine collagen controls. These findings establish fish-derived collagen as a viable alternative to mammalian sources for biomedical applications.