We obtained collagen from animals or vegetables. The most common sources of animal-derived collagen are bovine, porcine collagen, and marine organisms such as fish scales and skins. Of these animal sources, bovine collagen is frequently used as a temporary covering for extra-oral wounds and body burns. Bovine collagen is widely used due to its usefulness and biocompatibility. In contrast, porcine collagen matrices can be used for soft tissue transplantation. It provides a biocompatible surgical material as an alternative to autologous transplantation.
Terrestrial sources include chicken, kangaroo tail, rat-tail tendon, duck feet, horse tendons, crocodile skin, bird feet, sheepskin, and frog skin. Types I and II are derived from equine skin, cartilage, and flexor muscles. Types I, II, III, and V are derived from chicken necks. Type IX is found in the sternal cartilage of chicken embryos, types I and III are derived from the skin, and type IV is derived from the muscle tissue.
Collagen from the above sources is cheap and easy to obtain. Still, after long-term use and specific characterization, collagen from these sources is often allergic and misfolded, which can cause various diseases such as osteogenesis imperfecta. To address this issue, some modifications were made to the molecules mentioned in Section 1, and new sources of collagen were investigated. Another viable natural source is marine collagen. There are reports that this collagen has no risk of disease transmission and is FAD-approved as GRAS grade (recognized as safe). It is also an inexpensive raw material for production because many body parts contain this collagen and are ultimately wasted by humans. Table 2 lists some of the most common sources of marine collagen.
