Collagen gel contraction assay

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The collagen gel contraction assay is a type of wound contraction. It is performed using the dermal equivalent model, which consists of dermal fibroblasts seeded into a collagen gel. [1]

Wound healing The series of events that restore integrity to a damaged tissue, following an injury.

Wound healing is a complex process in which the skin, and the tissues under it, repair themselves after injury. In this article, wound healing is depicted in a discrete timeline of physical attributes (phases) constituting the post-trauma repairing process. In undamaged skin, the epidermis and dermis form a protective barrier against the external environment. When the barrier is broken, a regulated sequence of biochemical events is set into motion to repair the damage. This process is divided into predictable phases: blood clotting (hemostasis), inflammation, tissue growth (proliferation), and tissue remodeling (maturation). Blood clotting may be considered to be part of the inflammation stage instead of a separate stage.

The dermal equivalent is an in vitro model of the dermal layer of skin. It is constructed by seeding dermal fibroblasts into a collagen gel. This gel may then be allowed to contract as a model of wound contraction. This collagen gel contraction assay may be used to screen for treatments which promote or inhibit contraction and thus affect the development of a scar. Other cell types may be incorporated into the dermal equivalent to increase the complexity of the model. For example, keratinocytes may be seeded on the surface to create a skin equivalent, or macrophages may be incorporated to model the inflammatory phase of wound healing.

Dermal fibroblasts are cells within the dermis layer of skin which are responsible for generating connective tissue and allowing the skin to recover from injury. Using organelles, dermal fibroblasts generate and maintain the connective tissue which unites separate cell layers. Furthermore, these dermal fibroblasts produce the protein molecules including laminin and fibronectin which comprise the extracellular matrix. By creating the extracellular matrix between the dermis and epidermis, fibroblasts allow the epithelial cells of the epidermis to affix the matrix, thereby allowing the epidermal cells to effectively join together to form the top layer of the skin.

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Collagen is the main structural protein in the extracellular space in the various connective tissues in the body. As the main component of connective tissue, it is the most abundant protein in mammals, making 25% to 35% of the whole-body protein content. Collagen consists of amino acids wound together to form triple-helices of elongated fibrils. It is mostly found in fibrous tissues such as tendons, ligaments, and skin.

Gelatin mixture of peptides and proteins derived from connective tissues of animals

Gelatin or gelatine is a translucent, colorless, flavorless food ingredient, derived from collagen taken from animal body parts. Brittle when dry and gummy when moist, it is also called hydrolyzed collagen, collagen hydrolysate, gelatine hydrolysate, hydrolyzed gelatine, and collagen peptides. It is commonly used as a gelling agent in food, medications, drug and vitamin capsules, photographic films and papers, and cosmetics.

Vocal cords composed of twin infoldings of mucous membrane stretched horizontally, from back to front, across the larynx. They vibrate, modulating the flow of air being expelled from the lungs during phonation

The vocal cords, also known as vocal folds, are folds of tissue in the throat that are key in creating sounds through vocalization. The size of vocal cords affects the pitch of voice. Open when breathing and vibrating for speech or singing, the folds are controlled via the vagus nerve.

Scar area of fibrous tissue that replaces normal skin after an injury

A scar is an area of fibrous tissue that replaces normal skin after an injury. Scars result from the biological process of wound repair in the skin, as well as in other organs and tissues of the body. Thus, scarring is a natural part of the healing process. With the exception of very minor lesions, every wound results in some degree of scarring. An exception to this are animals with complete regeneration, which regrow tissue without scar formation.

Keloid An irregularly shaped, elevated mark on the skin caused by deposits of excessive amounts of collagen during wound healing. It extends beyond the original boundaries of the wound and may enlarge progressively.

Keloid, also known as keloid disorder and keloidal scar, is the formation of a type of scar which, depending on its maturity, is composed mainly of either type III (early) or type I (late) collagen. It is a result of an overgrowth of granulation tissue at the site of a healed skin injury which is then slowly replaced by collagen type 1. Keloids are firm, rubbery lesions or shiny, fibrous nodules, and can vary from pink to the color of the person's skin or red to dark brown in color. A keloid scar is benign and not contagious, but sometimes accompanied by severe itchiness, pain, and changes in texture. In severe cases, it can affect movement of skin. Keloid scars are seen 15 times more frequently in people of sub-Saharan African descent than in people of European descent.

Dermis layer of skin between the epidermis (with which it makes up the cutis) and subcutaneous tissues, that primarily consists of dense irregular connective tissue and cushions the body from stress and strain

The dermis or corium is a layer of skin between the epidermis and subcutaneous tissues, that primarily consists of dense irregular connective tissue and cushions the body from stress and strain. It is divided into two layers, the superficial area adjacent to the epidermis called the papillary region and a deep thicker area known as the reticular dermis. The dermis is tightly connected to the epidermis through a basement membrane. Structural components of the dermis are collagen, elastic fibers, and extrafibrillar matrix. It also contains mechanoreceptors that provide the sense of touch and thermoreceptors that provide the sense of heat. In addition, hair follicles, sweat glands, sebaceous glands, apocrine glands, lymphatic vessels, nerves and blood vessels are present in the dermis. Those blood vessels provide nourishment and waste removal for both dermal and epidermal cells.

An antihemorrhagic (antihæmorrhagic) agent is a substance that promotes hemostasis. It may also be known as a hemostatic agent.

Lip augmentation is a type of cosmetic surgery or non-surgical procedure that aims to alter the appearance of the lips by increasing their fullness through enlargement using fillers.

Myofibroblast

A myofibroblast is a cell that is in between a fibroblast and a smooth muscle cell in phenotype.

The lamina densa is a component of the basement membrane zone between the epidermis and dermis of the skin, and is an electron-dense zone between the lamina lucida and dermis, synthesized by the basal cells of the epidermis, and composed of (1) type IV collagen, (2) anchoring fibrils made of type VII collagen, and (3) dermal microfibrils.

Type-V collagen is a form of fibrillar collagen associated with classical Ehlers-Danlos syndrome. It is found within the dermal/epidermal junction, placental tissues, as well as in association with tissues containing Type-I collagen.

Photoaging or photoageing is a term used for the characteristic changes to skin induced by chronic UVA and UVB exposure. Tretinoin is the best studied retinoid in the treatment of photoaging

A skin equivalent is an in vitro skin model using to conduct experiments on processes involving the skin, such as wound healing and keratinocyte migration. It is a more complex form of the dermal equivalent.

Role of skin in locomotion describes how the integumentary system is involved in locomotion. Typically the integumentary system can be thought of as skin, however the integumentary system also includes the segmented exoskeleton in arthropods and feathers of birds. The primary role of the integumentary system is to provide protection for the body. However, the structure of the skin has evolved to aid animals in their different modes of locomotion. Soft bodied animals such as starfish rely on the arrangement of the fibers in their tube feet for movement. Eels, snakes, and fish use their skin like an external tendon to generate the propulsive forces need for undulatory locomotion. Vertebrates that fly, glide, and parachute also have a characteristic fiber arrangements of their flight membranes that allows for the skin to maintain its structural integrity during the stress and strain experienced during flight.

Copper peptide GHK-Cu naturally occurring copper complex of a glycyl-L-histidyl-L-lysine peptide. Since it has three amino acids it is called tripeptide

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Diabetic foot ulcer major complication of diabetes mellitus

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Scar free healing is the process by which significant injuries can heal without permanent damage to the tissue the injury has affected. In most healing, scars form due to the fibrosis and wound contraction, however in scar free healing tissue is completely regenerated. Scar improvement, and scar-free healing are an important and relevant area of medicine. During the 1990s, published research on the subject increased; it's a relatively recent term in the literature. Scar free healing is something which takes place in foetal life but the capacity is lost during progression to adulthood. In amphibians, tissue regeneration occurs, for example, as in skin regeneration in the adult axolotl.

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