Types & Sources of Stem Cells

Question 1

What are some reasons for tissue loss?

Answer 1

• accidents such as burns, abrasions, fractures
• cancer surgery
• tissue necrosis
• other diseases (osteogenesis imperfecta & congenital defects)

Question 2

Describe Tissue engineering

Answer 2

• aim of tissue engineering is to replace like with like, in the absence of tissue/organ donors

Question 3

What questions need to be considered before making a tissue in the lab?

Answer 3

• are they proliferative?
• can they grow easily in culture?
• are differentiated cells a good option?
  -what matrix is present ?

Question 4

What is a con of embryonic stem cell?

Answer 4

• ethical considerations are very challenging
• capacity for teratoma formation, which is when a tumour is formed that contains multiple tissues

Question 5

What are some examples of stem cells useful for tissue engineering?

Answer 5

• bone marrow
• adipose tissue
• umbilical cord blood/amniotic fluid
• skin cells induced to be pluripotent (iPSC)

Question 6

Describe Mesenhymal stem cells

Answer 6

• can be isolated from lots of different mesenchymal tissues
• MSC can be isolated from a bone marrow biopsy
• they can grow through multiple passages, meaning the initial biopsy can yield the first passage of cells

Question 7

What are two cell extraction methods?

Answer 7

• mechanical disruption
• enzymatic digestion

Question 8

What do mesenchymal stem cells need to grow in vitro?

Answer 8

• sterile environment
• incubator at 37 degrees with 5% CO2
• growth media = water, salts, protein source, growth factors, carb sources, antibiotics
• enough space to grow unhindered

Question 9

How is immunocytochemistry used to confim cell type?

Answer 9

• used in conjunction with microscopy
• primary antibody is targeted at the antigen of choice & secondary labelled antibody is targeted at the primary antibody
• when it detects a primary antibody it sticks to it & its labelled therefore detectable via a microscope

Question 10

Describe Flow Cytometry

Answer 10

• flow cytometry principle simialr to immunocytochemistry as its used labelled antibodies to detect antigens of interest
• cells aren’t observable via microscope - instead observed in a flow of fluid which passed through a detector that can recognise the label added to the cell