Debriding agents

Debridement refers to the process of cleaning a wound by removal of foreign material and dead tissue. Cleansing of the wound facilitates rapid healing and minimizes the risk of infection due to the presence of bacteria at the wound surface. The formation of a clot, followed by a scab, on a wound surface can trap bacteria, which then multiply (usually evidenced by the production of pus), slowing the healing process. Although debridement may be undertaken by physical means (e.g. cutting away dead tissue, washing/cleaning the wound), proteolytic enzymes are also often used to facilitate this process.

The value of proteases in cleansing tissue wounds has been appreciated for several hundred years. Wounds were sometimes cleansed in the past by application of protease-containing maggot saliva. Nowadays, this is usually more acceptably achieved by topical application of the enzyme to the wound surface. In some cases, the enzyme is formulated in an aqueous-based cream, and in others it is impregnated into special bandages. Trypsin, papain, collagenase and various microbial enzymes have been used in this regard.

Trypsin is a 24 kDa proteolytic enzyme synthesized by the mammalian pancreas in an inactive zymogen form: trypsinogen. Upon its release into the small intestine, it is proteolytically converted into trypsin by an enteropeptidase. Active trypsin plays a digestive role, hydrolysing peptide bonds in which the carboxyl group has been contributed by an arginine or lysine. Trypsin used medically is generally obtained by the enzymatic activation of trypsinogen, extracted from the pancreatic tissue of slaughterhouse animals.

Papain is a cysteine protease isolated from the latex of the immature fruit and leaves of the plant Carica papaya. It consists of a single 23.4 kDa, 212 amino acid polypeptide, and the purified enzyme exhibits broad proteolytic activity. Although it can be used as a debriding agent, it is also used for a variety of other industrial processes, including meat tenderizing and for the clarification of beverages.

Collagenase is a protease that can utilize collagen as a substrate. Although it can be produced by animal cell culture, certain microorganisms also produce this enzyme, most notably certain species of Clostridia (the ability of these pathogens to produce collagenase facilitates their rapid spread throughout the body). Collagenase used therapeutically is usually obtained from cell fermentation supernatants of Clostridium histolyticum. Such preparations are applied topically to promote debridement of wounds, skin ulcers and burns.

Chymotrypsin has also been utilized to promote debridement, as well as the reduction of soft tissue inflammation. It is also used in some opthalmic procedures, particularly in facilitating cataract extraction. It is prepared by activation of its zymogen, chymotrypsinogen, which is extracted from bovine pancreatic tissue.

Yet another proteolytic preparation used for debridement of wounds and skin ulcers consists of proteolytic enzymes derived from B. subtilis. The preparation displays broad proteolytic activity and is usually applied several times daily to the wound surface.

Diabetes 2

Diabetes 2

Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...

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