Collagen in the skin
A very large proportion of collagen is found in the skin, where it assumes an important supporting function for the skin layers and the adjacent connective tissue. As a protein, collagen has the property of binding water, which keeps the skin firm. Due to the special structure of collagen, the collagens are very elastic, which makes the skin very elastic and flexible.
The importance of collagen for skin firmness becomes apparent when the collagen content slowly decreases from around mid-20s onwards. Gradually, the first wrinkles appear, which has to do with the breakdown of collagen in the skin. The skin then loses its elasticity and collapses.
The skin’s own collagen production decreases significantly, which is why various cosmetic products in the form of creams or collagen building blocks such as proteins and amino acids try to fill the collagen cushion from the outside. Creams containing collagen or even direct injections into the skin are supposed to smooth the wrinkles and make the skin look firmer. Since collagen binds water, the skin should look firmer and fresher immediately after an injection treatment.
Types of collagen
Collagen is divided into different types, each of which has a different proportion in different organs. Collagen type I is about 300nm long and forms the typical structure of densely packed collagen fibrils, which can be between 50 and 200nm thick. In terms of quantity, collagen type 1 is the most abundant in the human body.
This type is particularly common in the skin, connective tissue, tendons, bones, muscle fascia and cornea. In these structures, the collagen is located in the extracellular matrix, i.e. the collagen surrounds the individual cells in skin, bones and tendons.By storing water in collagen, the organs gain mechanical strength. The high collagen type 1 content in the skin and tendons makes them particularly strong and elastic.
The colleague portion provides the necessary compressive strength and tautness of the various structures. One of the best known disorders of collagen type 1 synthesis is osteogenesis imperfecta. This is a glass bone disease, a hereditary defect in bone formation.
As a result, too little collagen is produced and the bone is less stable and resilient. Depending on the severity of the disease, it can be differently pronounced. Patients experience spontaneous and frequent bone fractures.
Deformations of the skull and spine can also occur. In addition, the patients usually do not grow very tall, as the disease affects the entire bone growth. Like type 1, type 2 collagen is also a fibrillar collagen.
In terms of length, the two types are very similar. Type 2 is also about 300nm long, but it is usually thinner than type 1 collagen. Type 2 collagen is particularly common in hyaline and elastic cartilage.
Hyaline cartilage lines the joints of the body and forms the uppermost layer of the joint space. Elastic cartilage is found, for example, on the auricle, the auditory canal and also in small bronchia of the lungs. While type 1 collagen has a dense structure, type 2 collagen fibers in the various structures are loose and isolated in the connective tissue. In addition to collagen, other substances such as proteoglycan and hyaluronic acid are found in the cartilage. Due to this composition and the accumulation of water, the cartilage becomes pressure-resistant, elastic and stretchable, but is not as stable as bone.