Lecture 13 - Tissue Engineering: Introduction Flashcards Preview

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Flashcards in Lecture 13 - Tissue Engineering: Introduction Deck (30):
1

What is a stem cell?

Undifferentiated cell
capable of slf-renewal

ability to differentiate into multiple cell types

defined by operation: maintain tissue and organ integrity

2

Why is stem cell research important?

Basci biology - cell fate decisions

Development - tissue formation

Homeostasis - tissue maintanance and turnover

Understand how alterations to steady state can result in disase

Potential to use cells as therapeutically

3

What are the classic stem cell properties?

renerwal

High proliferative potential

clonal repopulations _ single cell can form multiple cell types

multip-lineage differentiation

present in low marrows - rare

Quiscent - dormant (in niches)

morphologically unidentifiable

4

In responce to que's in the niche (microenvironment) - there is a triggering of..

proliferation - self renewal

then

differentiation - hrough transit amplifying progenitor cells which are intermediate cells that produce different types of mature cells

5

The more differentiated the cell is, the less..

proliferative potential

6

What types of niche's are there?

Restrictive - telling cell to stay quiscent

Permissive - go ahead


factors affecting the microenvironment can be cellular or a-cellular

7

ECM is comprised of

a network of macromolecules that provide strucutral support, and signalling molecules

Distribution and composition of ECM in different tissues is unique

8

Seemingly equal cells can behave differently depending on...

the microenvironment to which they are introduced

9

What determines cell fate?

Clues from Ontogeny

Cell-cell interactions, matrix, soluble factors required proliferation and differentiation

10

repair mechanisms often follow

developmental pathways

11

What are the option atm for when tissues or organs fail?

Transplantation - human donors, organ rejection

Prostheses - requires replacement, provides structural support but often limited function

12

What is tissue engineering?

Growing new tissues and organs for the maintenance/repair/improvement/replacement of damaged, diseases, or poorly functioning tissues or organs

13

What is the signifance of tissue complexity in realtion to tissue engineering bascics?

INcreasing fucntional parameters, metabolic requireemnts, cellular interactios, inter-organ-complications

All these increase the engineering complexity

14

What are the current limitations of tissue engineering?

vasculature

any tissue thicker than 400um must be vascularised

15

How are we addressing the lack of vasculature?

provide biochemical signals within transplant to stimulate endogenous angiogenesis and vascularisaion


the generation of well distributed blood vessels WITHIN engineered tissue in vitro remains a major challenge

16

Autologous cells are...

from own body

17

Alloogeneic cell are..

from another individual or speciesn - good because you can have them ready to go, but could be an immune response

18

What are some of the tissue engineering questions that need answering?

How do we isolate, where from

How do we generate enough cells for transplantation

how do we guide cells to differentiate and maintain desired phenotypes

how do we deliver cells to correct location

19

If needed immediately what are the options for Large organ and small organ tissue engineering?

Large Organ - Allogeneic adult SCs, ESCs

Small organ - Autologous adult SCs, allogeneic SCs

20

If NOT needed immediately what are the options for Large organ and small organ tissue engineering?

Large Organ - Autologous adults cells and iPSCs

Small ogran - Autologous adult primary cells, iPSCs

21

tissue engneering constructs are also influences by the presence of soluble

tissue engneering constructs are also influences by the presence of soluble growth factors

22

What are some examples tissue engineering constructs are also influences by the presence of soluble growth factorsf signalling molecules that are critical in development of differentiation of cell types?

BMPs
FGF-2
VEGF

can now be incorporated into ECM during scaffold fabrication

23

What functions does a scaffold have to serve?

provides 3D strucutre

space and strucural support

biomechanical que's

has to be biologically acceptive to body

degratable over time

should MIMIC the native ECM

promote the bodies production of ECM

24

What rate of ECM degradation is best?

the same as the rate of production of native ECM

25

What are some examples of scaffolds?

polypeptides

sythetic

can combine symthetic with ECM moietics

26

What factos give scaffolds different properties?

porosity (permeability)
cell adhesion
water content
mechanical properties
resorption and degradation
Haemostatic?

27

Decellularised tissues can be used for what?

providing an acellular, naturally occuring 3D scaffold containing ECM

the mechanical properties of the tissue are retained

28

CM is highly conserved acros species and will therefore be ..

well tolerated across individuals

29

what is the main problem with Decellularised tissues ?

still need an intact organ to start with - supply/demand issues

Still an new area of investigation

30

Bio 3D printing is able to..

deposit cells in a really sophisticated fashion - can have alternating cell types for instance