Term
| tissue engineering/regenerative medicine |
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Definition
| emerging multidisciplinary field involving biology, medicine, and engineering that is likely to revolutionize the ways we improve the health and quality of life for millions of people worldwide by restoring, maintaining or enhancing tissue and organ function |
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Term
| morula stage of development |
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Definition
1st differentiation that occurs after 3rd series of cleavage
-consists of inner blastomeres(inner cell mass)
-external cell differentiate to trophectoderm |
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Definition
*cells on the outside of the morula
*mediates implantation: formatino of extra embryonic structure(placenta)
*creates a fluid filled cavity by active transport of water to inside of the embryo |
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Definition
produced by cleavage of fertilized ovum and has ~128 cells w/ a large fluid filled space called Blastocoel
*after formation of morula, embroblast has inner cell mass-trophoblast |
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Term
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Definition
| phase in early embryonic development morphology turns into 3 germ layers: ecto, endo, and mesoderm |
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Definition
| skin, brain cells, nerve cells, part of the eye, mouth, anus, pituitary gland, adrenal gland, pigment cells |
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Definition
| lines the gastrointestinal: respiratory tracts, liver, pancreas, thyroid gland, thymus, lining of bladder |
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Definition
| skeletal muscle, heart, blood vessel, connective tissue, kidney, urethra, bone marrow, blood, bone, cartilage, fat |
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Term
what are stem cells?
what are 2 defining characteristics?
what are the 2 types of stem cells |
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Definition
limitless self renewing, multilineage differentiation
*are precursor cells that are capable of self renewal: differentiation into different cells
*somatic and embryonic |
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Definition
| complex process that leads to diversity in cell properties |
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Definition
| switch of a differential cell into another differentiated cell within the same or into a completely different tissue |
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Definition
some cells can dedifferentiate into less mature phenotype (i.e. chondrocytes can lose cartilage, turn into fibroblast)
*TGF (transforming growth factor): must be reintroduced to redifferentiate back to chondrocyte |
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Definition
| have the ability to form an entire organism(fertilized oocyte: the cells after first cleavage divisions) |
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Definition
| are able to form 3 gems into gem cells but not embryonic tissue (umbilical cord/placenta, inner cell mass of blastocyst) |
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Definition
| has the ability to form multiple cell types (mesenchymal can differentiate into bone, cartilage, fat) |
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Definition
| can differentiate into 2+ lineages (neural cells can form a subset of neurons) |
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Definition
| differentiate into one progenitor type. Has the ability to form cells from a single lineage (spermatogonial, stem cells) |
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Definition
| can differentiate or self renew |
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Definition
| begin cell differentiation but have to differentiate |
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Term
| important characteristics of embryonic stem cells |
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Definition
*unlimited self renewal
*pluripotent
*do not exist in body
*are in the inner cell mass of blastocyst |
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Term
| Harvesting embryonic stem cells |
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Definition
| use of blastocyst to take inner cell mass. those are transferred to a culture dish |
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Term
| invivo method determining embryonic stem cell potency |
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Definition
the injection of embryonic stem cells under skin or in kidney or testis of immunodificient mouse
*a benign tumor(teratoma) will form and all 3 germ layers will be present |
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Term
| chimeric mice show ultimate proof of pluripotency |
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Definition
use of ESC cells to form chimeric mice, cells contributed to formation of all tissues:germ layers
*only mouse embryonic stem cells: test whether # of chromosomes normal, test ES cell injected into cavity or blastocyst, transferred to psuedo-pregnant mouse, chimeric mice are produced |
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Term
| info embryonic stem cells |
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Definition
| indefinite proliferation capacity, pluripotency (neurons, insulin producing cells, cardiomyocytes), immune rejection issues, ethical concerns |
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Term
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Definition
can acquire in adults (bone marrow, dermal, menstrual, adipose, cardiac)
*non controversial, easy to isolate, availability
*difficult to differentiate, immune rejection
*shows promise with iPS |
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Term
| Induced Pluripotent cells (IPS) |
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Definition
*intorduction of 4 transcription factors reprogrammed into pluripotent state. Display similar morphology and growth phenotype of ES cells
*formed teratomas (tumor)
*IPS failed to produce chimeras |
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Term
| what is tissue homeostasis |
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Definition
*regulation involved w/ maintaining tissue; preventing regression in size and function
*cell turnover
*regeneration
*maintenance of a tissue by process of cell turnover/regeneration |
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Definition
*respond to loss of differentated cell
*uses stem cells to replace apoptotic cells
*normal physiological process |
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Definition
| difference between cell turnover regeneration. Is triggered by loss of limb/injury/disease |
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Term
| regeneration potential of liver, bone, cartilage, intestine, brain, heart |
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Definition
*liver: 75% of its mass. YES
*Bone: cell turnover 3 yrs. SLOW YES
*Cartilage: similar rate to bone. SLOW YES
*Intesine: High. Fast YES
*Brain: Neurons no renewal. NO
*Heart: No regenerative capacity. NO |
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Definition
*cellular environment that supports stem cells. shelters stem cells from differentiation, stimuli, apoptic signaling, and other signals
*intestinal, hair follical epidermal stem
hematopoietic |
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Term
| why is cell signaling important |
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Definition
cell to cell communication allows cells to respond to environment coordination of physiological behavior as a whole.
*Responds to environmental signals and organizes into functional tissue |
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Term
| what is the general pathway of cell signaling |
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Definition
a) reception: cell surface/intracellular receptors catch signaling molecule
b) activation of signal transduction: activate receptor, change extermal signal to intercellular message. aplification of signal, phosporylation/ dephosphorylation
c) Response: regulation of cellular activities. include protein activity (on/off gene) |
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Term
| hierarchical structure of collagen: function rolls: |
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Definition
Lowest to highest:collagen molecule-microfibirl-subfibril-fibril-fasicle-tendon
*fibers are unidirectional
*mechanical strength
*carries tension |
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Term
| mechanotransduction pathway |
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Definition
| collagen-fibronectin-integrin(transmembrane linear protein)-cytoskeleton-cell nucleus |
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Term
| things to consider for tissue engineered scaffold |
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Definition
*mechanical integrity
*Biocompatibility
*cells readily to attach
*degredation rate
*cells to regenerate the loss or damaged tissue
*scaffolds and matrices allow cell attachment and tissue ingrowth |
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Term
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Definition
acts as a temporary scaffold for cells and tissue. Disappears after degradation(degrades into metabolized molecules)
*PLA, PGA, PLGA into lactic and glycolic acids (Krebs) by hydrolysis/enzyme |
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Term
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Definition
| water soluble, non degradable (stable invivo), can be cleared away via urinary system |
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Term
| why are biodegradable polymers widely used in TE |
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Definition
*act as temporary scaffolds for cellular tissue(disappear after degradation)
*avoids chronic inflammation and foreign bodies |
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Term
| why is the degredation rate of PLG slower than PGA |
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Definition
| due to PGAs hydrophyllic nature it loses its mechanical stretch after 2 weeks |
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| 5 important factors that affect degredation rates biodegradable polymer |
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Definition
| *types of bonds, steric effect, hydrophyilicity, composition, acid/base catalyst |
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| what are 3 polymeric reaction mechanisms |
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Definition
*addition polymerization:
*step growth polymerization:
*ring opening polymerization |
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Term
| bulk degredation vs surface erosion |
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Definition
| diffusion of water into material vs surface degredation. surface degredation is better-longer period of time before dissipation of mass |
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Term
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Definition
chemical process in which a molecule is cleaved into two parts by the addition of a molecule of water. One fragment of the parent molecule gains a hydrogen ion, from the additional water molecule, the other group collects the remaining hydroxyl group.
*anhydride>ester>carbonate>amide.
* for proteins: Enzyme>hydrolysis |
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Definition
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Term
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Definition
Fetal bovine serum, DMEM-10% FBS and 1% antibiotic. Mediums for cell culture
*red: pH 7.4-best
*orange: pH 7.0-ok
*yellow: pH 6.5-time to change |
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Term
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Definition
| once cells become confluent cell growth slows, and ceases. RESEEDING AT LOWER CONCENTRATION |
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Term
| Integra tissue engineered skin |
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Definition
Top layer: silicone. enables immediate wound closure, controls fluid loss, provides mechanical protection, provides bacterial barrier, water vapor transmission similar to normal skin
*Bottom layer: 3-D matrix layer. cross-linked collagen and glycosaminoglycan, functions as extracellular matrix, promotes cellular growth and collagen synthesis, biodegrades while being replaced by autologous dermal tissue |
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