Collagens are a family of fibrous proteins which are the major component of the extracellular matrix (ECM) in animal organisms. This proteins are found in most tissues and organs (bones, cartilages, skin, ligaments, tendons, corneas). Main functions of collagens include the maintenance of structural integrity, elasticity and tensile strength of the connective tissue. Macromolecules from a collagen family are characterized by a unique structure rich in i.a. glycine, proline and hydroxyproline. The collagen structure consists of three left-handed polypeptide chains which are coiled around each other forming a right-handed rope-like super helix. This structure is stabilized by the presence of interstrand hydrogen bonds. To date, 29 types of collagen have been isolated and described. They differ from each other in structure, functions, and body distribution. Research development allowed to understand the structure and properties of native collagens which resulted in a production of artificial collagen fibrils used in nanotechnology and biomedicine. Collagen materials are considered to be the most useful biomaterials in medicine because of their properties such as non-toxicity, low antigenicity, high biocompatibility and biodegradability.