Related topics: cells · blood vessels

Cold plasma will heal non-healing wounds

Russian scientists have found that treating cells with cold plasma leads to their regeneration and rejuvenation. This result can be used to develop a plasma therapy program for patients with non-healing wounds. The paper ...

Researchers find the healing properties of a spider’s web

( -- The study of spider webs has led to a discovery that will generate new kinds of medical sutures embedded with medication. The University of Akron scientists have developed a novel synthetic material similar ...

New defence mechanism against bacteria discovered

Researchers in dermatology at Lund University in Sweden believe they have cracked the mystery of why we are able to quickly prevent an infection from spreading uncontrollably in the body during wounding. They believe this ...

Nanotech wound healing in diabetes

People with diabetes mellitus often suffer from impaired wound healing. Now, scientists in Egypt have developed antibacterial nanofibres of cellulose acetate loaded with silver that could be used in a new type of dressing ...

Math predicts size of clot-forming cells

UC Davis mathematicians have helped biologists figure out why platelets, the cells that form blood clots, are the size and shape that they are. Because platelets are important both for healing wounds and in strokes and other ...

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Wound healing

Wound healing, or wound repair, is an intricate process in which the skin (or some other organ) repairs itself after injury. In normal skin, the epidermis (outermost layer) and dermis (inner or deeper layer) exists in a steady-stated equilibrium, forming a protective barrier against the external environment. Once the protective barrier is broken, the normal (physiologic) process of wound healing is immediately set in motion. The classic model of wound healing is divided into three or four sequential, yet overlapping, phases: (1) hemostasis (not considered a phase by some authors), (2) inflammatory, (3) proliferative and (4) remodeling.

Upon injury to the skin, a set of complex biochemical events takes place in a closely orchestrated cascade to repair the damage. Within minutes post-injury, platelets (thrombocytes) aggregate at the injury site to form a fibrin clot. This clot acts to control active bleeding (hemostasis).

In the inflammatory phase, bacteria and debris are phagocytized and removed, and factors are released that cause the migration and division of cells involved in the proliferative phase.

The proliferative phase is characterized by angiogenesis, collagen deposition, granulation tissue formation, epithelialization, and wound contraction. In angiogenesis, new blood vessels are formed by vascular endothelial cells. In fibroplasia and granulation tissue formation, fibroblasts grow and form a new, provisional extracellular matrix (ECM) by excreting collagen and fibronectin. Concurrently, re-epithelialization of the epidermis occurs, in which epithelial cells proliferate and 'crawl' atop the wound bed, providing cover for the new tissue.

In contraction, the wound is made smaller by the action of myofibroblasts, which establish a grip on the wound edges and contract themselves using a mechanism similar to that in smooth muscle cells. When the cells' roles are close to complete, unneeded cells undergo apoptosis.

In the maturation and remodeling phase, collagen is remodeled and realigned along tension lines and cells that are no longer needed are removed by apoptosis.

However, this process is not only complex but fragile, and susceptible to interruption or failure leading to the formation of chronic non-healing wounds. Factors which may contribute to this include diabetes, venous or arterial disease, old age, and infection.

This text uses material from Wikipedia, licensed under CC BY-SA