Stem cells Flashcards
(23 cards)
what is meant by induced pluripotent stem cells (IPS cells)?
it is the conversion of mature cells to stem cells, innovated by shinya yamanka & Jhon gurdon noble prize winners
What is a stem cell?
a cell that can differentiate into any kind of cell
What is meant by Totipotent?
cells that can differentiate into embryonic and extraembryonic tissues (includes placental tissue)
What is the difference between pluripotent cells and totipotent?
pluripotent cells cannot give rise to extraembryonic cells (placenta)
What is multipotent?
cells that gives rise to limited number of tissues in a particular linage (ectoderm or mesoderm or endoderm)
what are some examples of adult stem cells?
1) blood cells
2) intestine lining
what is pluripotent stem cells (ESC)?
cells created from leftover embryos that are donated to the fertility clinic which can grow to any type of tissue
what is the difference between adult stem cells and pluripotent stem cells (ESC)?
pluripotent stem cell (ESC) can develop into any tissue
What is meand by induced pluripotent stem cells(iPSC)?
Fat, nerve muscle or skin induced to become pluripotent
does BMCs have the potential to differentiate into neural cells, cardiac myocytes, liver hepatocytes, chondrocytes, renal, corneal, blood, and myogenic cells?
YES its a multipotent stem cell capable of dividing to any of it linage
What is meant by a stem cell niche?
area of a tissue that provides a specific microenvironment where stem cells are present in an undifferentiated and not active form
What factors activate stem cells to maintain undifferentiated in the niche or to promote differentiation?
1) Cell signaling,
2) Structure of the niche (cells and extracellular matrix “ECM”),
3) Metabolic products
4) Hormonal factors
5) Neuronal factor
what are the application of stem cells?
1) Tissue engineering
2) Local therapy
3) Combined 1 & 2
what is tissue engineering?
Creating new tissues to replace the part of tissue that is damaged
what are the four things required for tissue engineering?
1) Scaffold
2) cells
3) growth factors & proper environment
4) physical and mechanical forces for the development of cells
what are the important things to consider when choosing a scaffold?
1- 3D configuration
2- Number of cells /mass
3- Material effect of differentiation
4- Incorporation of growth factors
5- Penetration of nutrients/oxygen to the center of the construct.
What are the types of scaffolds?
1) Natural (from our body, collagen/polysacchride)
2) Synthetic (biomaterial polymer or ceramic)
what is a scaffold?
3D structural material that allows cells to adhere, migrate and differentiate
how can we use a rat or big heart?
we decellularize them use them as a scaffold and then recellularize them and then grafted into the humans
where can we take stem cells from?
bone marrow or hip
what is an example of Local therapy?
Regenerate the damaged area in the heart post-myocardial infarction via injection of stem cells derived from BM of hip then the cells embed and regrow new muscles and blood vessels
what are the risk involved in stem cell transplantation?
1) Tumor formation (as they survive longer)
2) Inappropriate stem cell migration (from 1 million cells injected into the peripheral blood, 740 cells reach their target)
3) Immune rejection of transplanted stem cells
4) hemorrhage during neurosurgery
5) postoperative infection
What are the different clinical trial phases?
1) I & II Check safety
2) III & IV Assess the efficiency of the treatment and the mechanism
