|
Directed Differentiation
Directed differentiation is a bioengineering methodology at the interface of stem cell biology, developmental biology and tissue engineering. It is essentially harnessing the potential of stem cells by constraining their differentiation in vitro toward a specific cell type or tissue of interest. Stem cells are by definition pluripotent, able to differentiate into several cell types such as neurons, cardiomyocytes, hepatocytes, etc. Efficient ''directed differentiation'' requires a detailed understanding of the lineage and cell fate decision, often provided by developmental biology. Conceptual frame During differentiation, pluripotent cells make a number of developmental decisions to generate first the three germ layers (ectoderm, mesoderm and endoderm) of the embryo and intermediate progenitors, followed by subsequent decisions or check points, giving rise to all the body's mature tissues. The differentiation process can be modeled as sequence of binary decisions based on proba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioengineering
Biological engineering or bioengineering is the application of principles of biology and the tools of engineering to create usable, tangible, economically viable products. Biological engineering employs knowledge and expertise from a number of pure and applied sciences, such as mass transfer, mass and heat transfer, Kinetics (physics), kinetics, biocatalysts, biomechanics, bioinformatics, separation process, separation and List of purification methods in chemistry, purification processes, bioreactor design, surface science, fluid mechanics, thermodynamics, and polymer science. It is used in the design of medical devices, diagnostic equipment, biocompatible materials, renewable energy, ecological engineering, agricultural engineering, process engineering and catalysis, and other areas that improve the living standards of societies. Examples of bioengineering research include bacteria engineered to produce chemicals, new medical imaging technology, portable and rapid diagnosti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Probabilistic
Probability is a branch of mathematics and statistics concerning events and numerical descriptions of how likely they are to occur. The probability of an event is a number between 0 and 1; the larger the probability, the more likely an event is to occur."Kendall's Advanced Theory of Statistics, Volume 1: Distribution Theory", Alan Stuart and Keith Ord, 6th ed., (2009), .William Feller, ''An Introduction to Probability Theory and Its Applications'', vol. 1, 3rd ed., (1968), Wiley, . This number is often expressed as a percentage (%), ranging from 0% to 100%. A simple example is the tossing of a fair (unbiased) coin. Since the coin is fair, the two outcomes ("heads" and "tails") are both equally probable; the probability of "heads" equals the probability of "tails"; and since no other outcomes are possible, the probability of either "heads" or "tails" is 1/2 (which could also be written as 0.5 or 50%). These concepts have been given an axiomatic mathematical formaliza ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Growth Factors
A 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 cell signaling, signaling molecules between cells. Examples are cytokines and hormones that bind to specific receptor (biochemistry), receptors on the surface of their target cell (biology), cells. They often promote cell differentiation and maturation, which varies between growth factors. For example, epidermal growth factor (EGF) enhances osteogenic differentiation (osteogenesis or bone formation), while fibroblast growth factors and vascular endothelial growth factors stimulate blood vessel differentiation (angiogenesis). Comparison to cytokines ''Growth factor'' is sometimes used interchangeably among scientists with the term ''cytokine.'' Historically, cytok ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemically Defined Medium
A chemically defined medium (also known as synthetic medium) is a growth medium suitable for the in vitro cell culture of human cells, human or animal cells in which all of the chemical components are known. Standard cell culture media commonly consist of a basal medium supplemented with animal serum (such as fetal bovine serum, FBS) as a source of nutrients and other ill-defined factors. The technical disadvantages to using serum include its undefined nature, batch-to-batch variability in composition, and the risk of contamination. There is a clear distinction between serum-based media and chemically defined media. Serum-based media may contain undefined animal-derived products such as serum (purified from blood), hydrolysates, growth factors, hormones, carrier proteins, and attachment factors. These undefined animal-derived products will contain complex contaminants, such as the lipid content of albumin. In contrast, chemically defined media require that all of the components must ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extracellular Matrices
In biology, the extracellular matrix (ECM), also called intercellular matrix (ICM), is a network consisting of extracellular macromolecules and minerals, such as collagen, enzymes, glycoproteins and hydroxyapatite that provide structural and biochemical support to surrounding cells. Because multicellularity evolved independently in different multicellular lineages, the composition of ECM varies between multicellular structures; however, cell adhesion, cell-to-cell communication and differentiation are common functions of the ECM. The animal extracellular matrix includes the interstitial matrix and the basement membrane. Interstitial matrix is present between various animal cells (i.e., in the intercellular spaces). Gels of polysaccharides and fibrous proteins fill the interstitial space and act as a compression buffer against the stress placed on the ECM. Basement membranes are sheet-like depositions of ECM on which various epithelial cells rest. Each type of connective tissue in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
P19 Cell
P19 cells is an embryonic carcinoma cell line derived from an embryo-derived teratocarcinoma in mice. The cell line is pluripotent and can differentiate into cell types of all three germ layers. Also, it is the most characterized embryonic carcinoma (EC) cell line that can be induced into cardiac muscle cells and neuronal cells by different specific treatments. Indeed, exposing aggregated P19 cells to dimethyl sulfoxide (DMSO) induces differentiation into cardiac and skeletal muscle. Also, exposing P19 cells to retinoic acid (RA) can differentiate them into neuronal cells. Origin of the P19 cell line Cancer cells in humans may result in the patient's death if the aggressive cancer cell grows and metastasizes. However, researchers utilize these cells to study the development of cancer cells in order to find more specific treatments. For developmental biologists, embryonal carcinoma, which is derived from teratocarcinoma, is a good object for developmental study. In 1982, McBurney an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Induced Pluripotent Stem Cells
Induced pluripotent stem cells (also known as iPS cells or iPSCs) are a type of pluripotent stem cell that can be generated directly from a somatic cell. The iPSC technology was pioneered by Shinya Yamanaka and Kazutoshi Takahashi in Kyoto, Japan, who together showed in 2006 that the introduction of four specific genes (named Myc, Oct3/4, Sox2 and Klf4), collectively known as Yamanaka factors, encoding transcription factors could convert somatic cells into pluripotent stem cells. Shinya Yamanaka was awarded the 2012 Nobel Prize along with Sir John Gurdon "for the discovery that mature cells can be reprogrammed to become pluripotent." Pluripotent stem cells hold promise in the field of regenerative medicine. Because they can propagate indefinitely, as well as give rise to every other cell type in the body (such as neurons, heart, pancreatic, and liver cells), they represent a single source of cells that could be used to replace those lost to damage or disease. The most w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embryonic Stem Cells
Embryonic stem cells (ESCs) are Cell potency#Pluripotency, pluripotent stem cells derived from the inner cell mass of a blastocyst, an early-stage pre-Implantation (human embryo), implantation embryo. Human embryos reach the blastocyst stage 4–5 days post Human fertilization, fertilization, at which time they consist of 50–150 cells. Isolating the inner cell mass (embryoblast) using immunosurgery results in destruction of the blastocyst, a process Stem cell controversy, which raises ethical issues, including whether or not embryos at the pre-implantation stage have the same moral considerations as embryos in the post-implantation stage of development. Researchers are currently focusing heavily on the therapeutic potential of embryonic stem cells, with clinical use being the goal for many laboratories. Potential uses include the treatment of diabetes and heart disease. The cells are being studied to be used as clinical therapies, models of genetic disorders, and cellular/DNA r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biomedical Research
Medical research (or biomedical research), also known as health research, refers to the process of using scientific methods with the aim to produce knowledge about human diseases, the prevention and treatment of illness, and the promotion of health. Medical research encompasses a wide array of research, extending from " basic research" (also called ''bench science'' or ''bench research''), – involving fundamental scientific principles that may apply to a ''preclinical'' understanding – to clinical research, which involves studies of people who may be subjects in clinical trials. Within this spectrum is applied research, or translational research, conducted to expand knowledge in the field of medicine. Both clinical and preclinical research phases exist in the pharmaceutical industry's drug development pipelines, where the clinical phase is denoted by the term ''clinical trial''. However, only part of the clinical or preclinical research is oriented towards a specific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pluripotent Stem Cell
Cell potency is a cell's ability to differentiate into other cell types. The more cell types a cell can differentiate into, the greater its potency. Potency is also described as the gene activation potential within a cell, which like a continuum, begins with totipotency to designate a cell with the most differentiation potential, pluripotency, multipotency, oligopotency, and finally unipotency. Totipotency Totipotency () is the ability of a single cell to divide and produce all of the differentiated cells in an organism. Spores and zygotes are examples of totipotent cells. In the spectrum of cell potency, totipotency represents the cell with the greatest differentiation potential, being able to differentiate into any embryonic cell, as well as any extraembryonic tissue cell. In contrast, pluripotent cells can only differentiate into embryonic cells. A fully differentiated cell can return to a state of totipotency. The conversion to totipotency is complex and not fully unders ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signaling Pathways
Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a series of molecular events. Proteins responsible for detecting stimuli are generally termed receptors, although in some cases the term sensor is used. The changes elicited by ligand binding (or signal sensing) in a receptor give rise to a biochemical cascade, which is a chain of biochemical events known as a signaling pathway. When signaling pathways interact with one another they form networks, which allow cellular responses to be coordinated, often by combinatorial signaling events. At the molecular level, such responses include changes in the transcription or translation of genes, and post-translational and conformational changes in proteins, as well as changes in their location. These molecular events are the basic mechanisms controlling cell growth, proliferation, metabolism and many other processes. In multicellular organisms, signal transduction pathways regulate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organogenesis
Organogenesis is the phase of embryonic development that starts at the end of gastrulation and continues until birth. During organogenesis, the three germ layers formed from gastrulation (the ectoderm, endoderm, and mesoderm) form the internal organs of the organism. The cells of each of the three germ layers undergo differentiation, a process where less-specialized cells become more-specialized through the expression of a specific set of genes. Cell differentiation is driven by cell signaling cascades. Differentiation is influenced by extracellular signals such as growth factors that are exchanged to adjacent cells which is called juxtracrine signaling or to neighboring cells over short distances which is called paracrine signaling. Intracellular signals – a cell signaling itself ( autocrine signaling) – also play a role in organ formation. These signaling pathways allow for cell rearrangement and ensure that organs form at specific sites within the organism. The organogen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
