Collagen is the most abundant protein in the human body, found in the bones, muscles, skin, and tendons.
It is the substance that holds the body together. Collagen forms a scaffold to provide strength and structure. Endogenous collagen is natural collagen, synthesized by the body. Exogenous collagen is synthetic. It comes from an outside source, such as supplements. Endogenous collagen has a number of important functions. Breakdown and depletion is linked to a number of health problems. Exogenous collagen is used for medical and cosmetic purposes, including the repair of body tissues.
What is collagen?
Collagen is a hard, insoluble, and fibrous protein that makes up one-third of the protein in the human body. In most collagens, the molecules are packed together to form long, thin fibrils. These act as supporting structures and anchor cells to each other. They give the skin strength and elasticity.
The collagens in the human body are strong and flexible.
What does collagen do?
Collagen is secreted by various cells, but mainly by connective tissue cells.
It is found in the extracellular matrix. This is an intricate network of macromolecules that determines the physical properties of body tissues. A macromolecule is a molecule containing a large number of atoms.
In the dermis, or the middle layer of skin, collagen helps form a fibrous network of cells called fibroblasts, upon which new cells can grow. It also plays a role in replacing and restoring dead skin cells.
Some collagens act as protective coverings for delicate organs in the body, such as the kidneys. With age, the body produces less collagen. The structural integrity of the skin declines. Wrinkles form, and joint cartilage weakens.
Women experience a dramatic reduction in collagen synthesis after menopause.
Medical and cosmetic
Collagen is resorbable. This means it can be broken down, converted, and absorbed back into the body. It can also be formed into compacted solids or lattice-like gels. Its diverse range of functions and the fact that it is naturally occurring make it clinically versatile and suitable for various medical purposes.
Collagen injections can improve the contours of the skin and fill out depressions. Fillers that contain collagen can be used cosmetically to remove lines and wrinkles from the face. It can also improve scars, as long as these do not have a sharp edge. These fillers are sourced from humans and cows. Skin tests should be done before using collagen from cows, to avoid aggravating any allergies.
Collagen can fill relatively superficial volumes. More extensive gaps are usually filled with substances such as fat, silicone, or implants.
Collagen can help heal wounds by attracting new skin cells to the wound site. It promotes healing and provides a platform for new tissue growth. Collagen dressings are not recommended for third-degree burns, wounds covered in dry eschar, or for patients who may be sensitive to products.
Guided tissue regeneration
Collagen-based membranes have been used in periodontal and implant therapy to promote the growth of specific types of cell. In oral surgery, collagen barriers can prevent fast-growing cells around the gum from migrating to a wound in a tooth. This preserves a space where tooth cells have the chance to regenerate. Collagen-based membranes can aid healing in these cases, and they are resorbable, so this barrier does not need to be surgically removed after the main operation.
Collagen tissue grafts from donors have been used in peripheral nerve regeneration, in vascular prostheses, and in arterial reconstruction. While collagen prostheses are compatible with the human body, some have been found to be thrombogenic, or likely to cause coagulation of the blood.
Treatment of osteoarthritis
Collagen supplements or formulations may help treat osteoarthritis. Supplements containing collagen helped decrease painful symptoms and improving joint function in people with osteoarthritis. As the supplement was absorbed, collagen accumulated in the cartilage, and this helped to rebuild the extracellular matrix.