Terminology

 

 

Biomaterials— Creating new materials for tissue engineering and stem cell delivery as well as for other application such as drug delivery and understanding the molecular mechanisms of the host response to biomaterials and biomaterial based devices.

Blastocyst— A hollow sphere of cells formed four days after a sperm fertilizes an egg.  This cluster of cells represents multiple cell divisions that have occurred in the fallopian tube after successful fertilization of an ovum by a sperm. This is the developmental form which must leave the fallopian tube, enter the uterus, and implant itself in the uterus to achieve actual pregnancy.

Bone marrow — A soft, spongy tissue that fills the cavities inside most bones in the human body. Bone marrow is a source of stem cells that manufacture red blood cells, white blood cells and platelets. It is a conventional source fro stem cell transplantation.

Bone marrow stromal cells— A population of cells found in bone marrow that are different from blood cells.

Bone marrow stromal stem cells (skeletal stem cells)— A multipotent subset of bone marrow stromal cells able to form bone, cartilage, stromal cells that support blood formation, fat, and fibrous tissue.

Cell-based therapies— Treatment in which stem cells are induced to differentiate into the specific cell type required to repair damaged or destroyed cells or tissues.

Cell division— Method by which a single cell divides to create two cells. There are two main types of cell division depending on what happens to the chromosomes: mitosis and meiosis.

Cellular therapyA field of medicine that uses cells to repair tissues that have been damaged by human disease or to generate new tissues with desired functional activities.Cell culture—Growth of cells in vitro in an artificial medium for research or medical treatment.

Chromosome— A structure consisting of DNA and regulatory proteins found in the nucleus of the cell. The DNA in the nucleus is usually divided up among several chromosomes.The number of chromosomes in the nucleus varies depending on the species of the organism. Humans have 46 chromosomes.

Cord blood— Blood remaining in the umbilical cord immediately following the birth of the baby. It contains a rich concentration of stem cells.

Embryo— In humans, the developing organism from the time of fertilization until the end of the eighth week of gestation, when it is called a fetus.

Embryonic stem cells— Primitive (undifferentiated) cells that are derived from preimplantation-stage embryos,  are capable of dividing without differentiating for a prolonged period in culture, and are known to develop into cells and tissues of the three primary germ layers.

Embryonic stem cell line— Embryonic stem cells, which have been cultured under in vitro conditions that allow proliferation without differentiation for months to years.

Endogenous stem cells— Stem cells that are already present in the body.

Enucleated— Having had its nucleus removed.

Epigenetic— Having to do with the process by which regulatory proteins can turn genes on or off in a way that can be passed on during cell division.

Gamete— An egg (in the female) or sperm (in the male) cell. See also Somatic cell.

Gene— A functional unit of heredity that is a segment of DNA found on chromosomes in the nucleus of a cell. Genes direct the formation of an enzyme or other protein.

Hematopoietic stem cell— A stem cell that gives rise to all red and white blood cells and platelets.

Induced pluripotent stem cell (iPSC)— A type of pluripotent stem cell, similar to an embryonic stem cell, formed by the introduction of certain embryonic genes into a somatic cell.

Inner cell mass— A cluster of cells in the blastocyst from which embryonic stem cell lines can be isolated and grown in culture.

In vitro— describes a state or condition that occurs and /or exists outside the body. This term often refers to testing conditions that occur in a laboratory environment.

In vivo— describes a state or condition that occurs and/or exists within the body. This term is often used to describe testing conditions that occur within humans and/or animals.

Mesenchymal stem cells— A term that is currently used to define non-blood adult stem cells from a variety of tissues, although it is not clear that mesenchymal stem cells from different tissues are the same.

Microenvironment— The molecules and compounds such as nutrients and growth factors in the fluid surrounding a cell in an organism or in the laboratory, which play an important role in determining the characteristics of the cell.

Neuronal/neural stem cells— Cells capable of becoming tissues of the brain and central nervous system.

Neural stem cell— A stem cell found in adult neural tissue that can give rise to neurons and glial (supporting) cells. Examples of glial cells include astrocytes and oligodendrocytes.

Neurons— Nerve cells, the principal functional units of the nervous system. A neuron consists of a cell body and its processes—an axon and one or more dendrites. Neurons transmit information to other neurons or cells by releasing neurotransmitters at synapses.

Oligodendrocyte— A supporting cell that provides insulation to nerve cells by forming a myelin sheath (a fatty layer) around axons.

Parthenogenesis— The artificial activation of an egg in the absence of a sperm; the egg begins to divide as if it has been fertilized.

Passage— In cell culture, the process in which cells are disassociated, washed, and seeded into new culture vessels after a round of cell growth and proliferation. The number of passages a line of cultured cells has gone through is an indication of its age and expected stability.

Pluripotent— capable of giving rise to most tissues of an organism.

Progenitor cell— A biological cell that has the same ability to transform itself into different types of cells as stem cells, but is more specific than the latter in the types of cells that it can differentiate into.

Regenerative medicine— Regenerative medicine represents a new paradigm in human health, with the potential to resolve unmet medical needs by addressing the underlying causes of disease. Regenerative medicine research translates fundamental knowledge in biology, chemistry and physics into materials, devices, systems and a variety of therapeutic strategies which augment, repair, replace or regenerate organs and tissues. This rapidly evolving, interdisciplinary field in healthcare is transforming the practice of medicine, medical innovation and the production of medical devices and therapies. (Source: Alliance for Regenerative Medicine)

Reproductive cloning— Reproductive cloning is the use of cloning technology to create a child.  Reproductive cloning results in a copy of a specific human being. Patient advocacy groups and leading scientists, and a majority of Americans agree that human reproductive cloning should not be allowed. Therapeutic cloning, however, is entirely different.

Signals— Internal and external factors that control changes in cell structure and function. They can be chemical or physical in nature.

Somatic cell— Any body cell other than gametes (egg or sperm); sometimes referred to as “adult” cells. See also Gamete.

Somatic cell nuclear transfer (SCNT)— A technique that combines an enucleated egg and the nucleus of a somatic cell to make an embryo. SCNT can be used for therapeutic or reproductive purposes, but the initial stage that combines an enucleated egg and a somatic cell nucleus is the same. See also therapeutic cloning and reproductive cloning.

Somatic (adult) stem cells—A relatively rare undifferentiated cell found in many organs and differentiated tissues with a limited capacity for both self renewal (in the laboratory) and differentiation. Such cells vary in their differentiation capacity, but it is usually limited to cell types in the organ of origin. This is an active area of investigation.

Stem Cell Bioengineering— Devising processes to control the differentiation and/or self-renewal of mesenchymal and adult progenitor cells and understanding the underlying mechanisms of these processes.

Stem cells — cells that have the ability to divide for indefinite periods in culture and give rise to specialized cells. There are many sources of stem cells, including human embryonic cells (hESC), adult stem cells (ASC or tissue stem cells), and induced pluripotent cells (iPS). Stem cells are an important resource for research and medical treatments because of their ability to become almost any other cell in the body.

Stromal cells— Connective tissue cells found in virtually every organ. In bone marrow, stromal cells support blood formation

Telomere— The end of a chromosome, associated with a characteristic DNA sequence that is replicated in a special way. A telomere counteracts the tendency of the chromosome to shorten with each round of replication.

Teratoma— A multi-layered benign tumor that grows from pluripotent cells injected into mice with a dysfunctional immune system. Scientists test whether they have established a human embryonic stem cell (hESC) line by injecting putative stem cells into such mice and verifying that the resulting teratomas contain cells derived from all three embryonic germ layers.

Therapeutic Cloning— Therapeutic cloning is another phrase for a procedure known as somatic cell nuclear transfer (SCNT).  The nucleus that is extracted from the somatic cell in the patient is then inserted into the egg, which had its nucleus previously removed. In a very basic sense, it's a procedure of substitution. The egg now contains the patient's genetic material, or instructions. In therapeutic cloning, no sperm fertilisation is involved nor is there implantation into the uterus to create a child.   In practical human applications, the somatic cell would be taken from a patient who requires a stem cell transplant to treat a health condition or disease.

Tissue Engineering— An interdisciplinary field that applies the principles of engineering and life sciences toward the development of biological substitutes that restore, maintain, or improve tissue function or a whole organ. Tissue engineering has also been defined as understanding the principles of tissue growth, and applying this to produce functional replacement tissue for clinical use.  Constructing devices combining cells and biocompatible materials to effect tissue repair or replacement in the context of cardiovascular disease, diabetes, and cartilage and bone repair, etc.

Totipotent— Having unlimited capability. Totipotent cells have the capacity to specialize into extra-embryonic membranes and tissues, the embryo, and all post-embryonic tissues and organs.

Transplantation— The process of giving tissues or cells to treat a disease. The tissue or cells may come from the same patient (autologous) or from another person (allogenic).

Umbilical cord blood stem cells— Stem cells collected from the umbilical cord at birth that can produce all of the blood cells in the body (hematopoietic). Cord blood is currently used to treat patients who have undergone chemotherapy to destroy their bone marrow due to cancer or other blood-related disorders.

Undifferentiated— A cell that has not yet developed into a specialized cell type.