Stem Cells

Question 1

Define division

Answer 1

Replication of cells, leading to growth

Question 2

Define determination

Answer 2

Internal mechanisms determine the identity a stem cell will become

Question 3

Define differentiation

Answer 3

Cell changes morphology and other characteristics, becoming a specialised cell type

Question 4

What are the 2 types of growth and which animals do each?

Answer 4

Continuous= Fish and Crustaceans

Determinate- Birds and mammals

Question 5

Name examples of permeant cells that cant be replaced

Answer 5

Eye lenses

Eye rods cells

Question 6

What are the 3 types of stem cells

Answer 6

unipotent
multipotent/pluripotent
totipotent

Question 7

Define unipotent

Answer 7

stem cells become one cell type

Question 8

Define pluripotent

Answer 8

becomes several cell types

Question 9

Define totipotent

Answer 9

stem cell can become ALL cell types

Question 10

Name an example of a unipotent stem cell

Answer 10

Olfactory basal cell in the nose

Question 11

Name an example of a multipotent stem cell

Answer 11

Gut epithelium

Question 12

Name an example of a pluripotent stem cell

Answer 12

bone marrow

Question 13

Name an example of a totipotent stem cell

Answer 13

early embryo cells >16

Question 14

What are the 3 sources of stem cells

Answer 14

1) Culture cells from early embryo
2) Adult stem cell collection + culture
3) De-differentiate adult cells in culture

Question 15

What are the benifits + negatives to adult stem cell collection

Answer 15

Ethically and immunologically good
BUT
not numerous and may not exist for all tissue types

Question 16

What are the 3 challenges to 3D printing

Answer 16

1. Adapt technologies designed to print molten plastics
   and metals to instead print sensitive living cells
2. Recreate the fine structure of the ECM to
   allow biological function
3. Incorporate multiple cell types in sufficient resolution

Question 17

How does 2D printing work?

Answer 17

Ink onto paper matric or substrate. Single layer of cells

Question 18

What are 3 types of approaches to 3D printing?

Answer 18

Biomimicry
Autonomous self-assembly
Mini-tissue building blocks

Question 19

What cells are used for 3D printing?

Answer 19

autologous adult stem cells
Mesenchymal stem cells
Embryonic stem cells

Question 20

Embryonic-like stem cells and induced pluripotent cells (iPS) unlimited potential cell types. Why are these advantageous?

Answer 20

Immune tolerance

reduced possibility of disease transmission

Question 21

What are the 4 challenges of scaffold based engineering?

Answer 21

Immune or inflammatory response against scaffold matrix

Mechanical mismatch with surrounding tissue

Difficulty in getting uniform distribution of high numbers of cells throughout the matrix

Difficulty in precise positioning of different cell types

Question 22

How is a liver constructed on a chip?

Answer 22

HepG2/C3A human hepatocarcinoma cells formed into 191 μm spheroids

Spheroids suspended in gelatin methacryloyl (GelMA) - natural ECM-derived hydrogel scaffold

Printed in a 7 x 7 array

Cell number increased 10-fold over a 30 days incubation period

Drugs can be tested for efficacy prior to clinical trials

Induced pluripotent stem cells (iPSCs) could be used to test cells from specific patients.

Similar for cardiac, skeletal muscle cells, cancer tissues