Wound healingWound healing refers to a living organism's replacement of destroyed or damaged tissue by newly produced tissue. In undamaged skin, the epidermis (surface, epithelial layer) and dermis (deeper, connective layer) 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 (cell proliferation), and tissue remodeling (maturation and cell differentiation).
Adult stem cellAdult stem cells are undifferentiated cells, found throughout the body after development, that multiply by cell division to replenish dying cells and regenerate damaged tissues. Also known as somatic stem cells (from Greek σωματικóς, meaning of the body), they can be found in juvenile, adult animals, and humans, unlike embryonic stem cells. Scientific interest in adult stem cells is centered around two main characteristics.
Regulation of gene expressionRegulation of gene expression, or gene regulation, includes a wide range of mechanisms that are used by cells to increase or decrease the production of specific gene products (protein or RNA). Sophisticated programs of gene expression are widely observed in biology, for example to trigger developmental pathways, respond to environmental stimuli, or adapt to new food sources. Virtually any step of gene expression can be modulated, from transcriptional initiation, to RNA processing, and to the post-translational modification of a protein.
Cell cultureCell culture or tissue culture is the process by which cells are grown under controlled conditions, generally outside of their natural environment. The term "tissue culture" was coined by American pathologist Montrose Thomas Burrows. This technique is also called micropropagation. After the cells of interest have been isolated from living tissue, they can subsequently be maintained under carefully controlled conditions. They need to be kept at body temperature (37 °C) in an incubator.
Stem cellIn multicellular organisms, stem cells are undifferentiated or partially differentiated cells that can differentiate into various types of cells and proliferate indefinitely to produce more of the same stem cell. They are the earliest type of cell in a cell lineage. They are found in both embryonic and adult organisms, but they have slightly different properties in each. They are usually distinguished from progenitor cells, which cannot divide indefinitely, and precursor or blast cells, which are usually committed to differentiating into one cell type.
Gene expressionGene expression is the process by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, proteins or non-coding RNA, and ultimately affect a phenotype. These products are often proteins, but in non-protein-coding genes such as transfer RNA (tRNA) and small nuclear RNA (snRNA), the product is a functional non-coding RNA.
Tissue engineeringTissue engineering is a biomedical engineering discipline that uses a combination of cells, engineering, materials methods, and suitable biochemical and physicochemical factors to restore, maintain, improve, or replace different types of biological tissues. Tissue engineering often involves the use of cells placed on tissue scaffolds in the formation of new viable tissue for a medical purpose but is not limited to applications involving cells and tissue scaffolds.
Artificial skinArtificial skin is a collagen scaffold that induces regeneration of skin in mammals such as humans. The term was used in the late 1970s and early 1980s to describe a new treatment for massive burns. It was later discovered that treatment of deep skin wounds in adult animals and humans with this scaffold induces regeneration of the dermis. It has been developed commercially under the name Integra and is used in massively burned patients, during plastic surgery of the skin, and in treatment of chronic skin wounds.
Antimicrobial peptidesAntimicrobial peptides (AMPs), also called host defence peptides (HDPs) are part of the innate immune response found among all classes of life. Fundamental differences exist between prokaryotic and eukaryotic cells that may represent targets for antimicrobial peptides. These peptides are potent, broad spectrum antimicrobials which demonstrate potential as novel therapeutic agents. Antimicrobial peptides have been demonstrated to kill Gram negative and Gram positive bacteria, enveloped viruses, fungi and even transformed or cancerous cells.
Wound bed preparationWound bed preparation (WBP) is a systematic approach to wound management by identifying and removing barriers to healing. The concept was originally developed in plastic surgery. During the year 2000, the concept was applied to systematizing the treatment of chronic wounds. The 2000 proposals recommended that wound management address the identifiable impediments to healing in order to achieve more successful outcomes. Three publications appeared that year that focused on the concept of managing the healing processes of a wound exudate, bioburden and devitalized tissue.
Skin graftingSkin grafting, a type of graft surgery, involves the transplantation of skin. The transplanted tissue is called a skin graft. Surgeons may use skin grafting to treat: extensive wounding or trauma burns areas of extensive skin loss due to infection such as necrotizing fasciitis or purpura fulminans specific surgeries that may require skin grafts for healing to occur – most commonly removal of skin cancers Skin grafting often takes place after serious injuries when some of the body's skin is damaged.
WoundA wound is a rapid onset of injury that involves lacerated or punctured skin (an open wound), or a contusion (a closed wound) from blunt force trauma or compression. In pathology, a wound is an acute injury that damages the epidermis of the skin. To heal a wound, the body undertakes a series of actions collectively known as the wound healing process. According to the level of contamination, a wound can be classified as: Clean wound – made under sterile conditions where there are no organisms present, and the skin is likely to heal without complications.
Growth factorA growth factor is a naturally occurring substance capable of stimulating cell proliferation, wound healing, and occasionally cellular differentiation. Usually it is a secreted protein or a steroid hormone. Growth factors are important for regulating a variety of cellular processes. Growth factors typically act as signaling molecules between cells. Examples are cytokines and hormones that bind to specific receptors on the surface of their target cells. They often promote cell differentiation and maturation, which varies between growth factors.
HealingWith physical trauma or disease suffered by an organism, healing involves the repairing of damaged tissue(s), organs and the biological system as a whole and resumption of (normal) functioning. Medicine includes the process by which the cells in the body regenerate and repair to reduce the size of a damaged or necrotic area and replace it with new living tissue. The replacement can happen in two ways: by regeneration in which the necrotic cells are replaced by new cells that form "like" tissue as was originally there; or by repair in which injured tissue is replaced with scar tissue.
AngiogenesisAngiogenesis is the physiological process through which new blood vessels form from pre-existing vessels, formed in the earlier stage of vasculogenesis. Angiogenesis continues the growth of the vasculature mainly by processes of sprouting and splitting, but processes such as coalescent angiogenesis, vessel elongation and vessel cooption also play a role. Vasculogenesis is the embryonic formation of endothelial cells from mesoderm cell precursors, and from neovascularization, although discussions are not always precise (especially in older texts).
Transcriptional regulationIn molecular biology and genetics, transcriptional regulation is the means by which a cell regulates the conversion of DNA to RNA (transcription), thereby orchestrating gene activity. A single gene can be regulated in a range of ways, from altering the number of copies of RNA that are transcribed, to the temporal control of when the gene is transcribed. This control allows the cell or organism to respond to a variety of intra- and extracellular signals and thus mount a response.
Cell migrationCell migration is a central process in the development and maintenance of multicellular organisms. Tissue formation during embryonic development, wound healing and immune responses all require the orchestrated movement of cells in particular directions to specific locations. Cells often migrate in response to specific external signals, including chemical signals and mechanical signals. Errors during this process have serious consequences, including intellectual disability, vascular disease, tumor formation and metastasis.
Chronic woundA chronic wound is a wound that does not heal in an orderly set of stages and in a predictable amount of time the way most wounds do; wounds that do not heal within three months are often considered chronic. Chronic wounds seem to be detained in one or more of the phases of wound healing. For example, chronic wounds often remain in the inflammatory stage for too long. To overcome that stage and jump-start the healing process, a number of factors need to be addressed such as bacterial burden, necrotic tissue, and moisture balance of the whole wound.
Amniotic stem cellsAmniotic stem cells are the mixture of stem cells that can be obtained from the amniotic fluid as well as the amniotic membrane. They can develop into various tissue types including skin, cartilage, cardiac tissue, nerves, muscle, and bone. The cells also have potential medical applications, especially in organ regeneration. The stem cells are usually extracted from the amniotic sac by amniocentesis which occurs without harming the embryos.
Gene expression profilingIn the field of molecular biology, gene expression profiling is the measurement of the activity (the expression) of thousands of genes at once, to create a global picture of cellular function. These profiles can, for example, distinguish between cells that are actively dividing, or show how the cells react to a particular treatment. Many experiments of this sort measure an entire genome simultaneously, that is, every gene present in a particular cell. Several transcriptomics technologies can be used to generate the necessary data to analyse.
