Table 1.

The function of the 5 most common types of collagens [2].

Collagen	Function or Application	Tissue or Organ
Type I	the organic part of the bone, membranes for guided tissue regeneration	skin, bone, teeth, tendon, ligament, vascular ligature
Type II	the main constituent of cartilage, cartilage repair, and arthritis treatment	cartilage
Type III	the main constituent of reticular fibers, hemostats, and tissue sealants	muscle, blood vessels
Type IV	the major component of the basement membrane, attachment enhancer of cell culture, and diabetic nephropathy indicator	basal lamina, the epithelium-secreted layer of the basement membrane
Type V	feedstock for biomaterials in corneal treatments	hair, cell surfaces, and placenta.