Module 11

Question 1

Major function of bioreactors:

Answer 1

Devices used extensively in tissue engineering to ENABLE the fabrication of 3D artificial tissue and SUPPORT the growth, maturation, and development of artificial tissue engineering during controlled in vitro culture

Question 2

Effects of perfusion on cell seeding

Answer 2

Cells will penetrate the whole scaffold and perfuse more homogenous

Question 3

Methods for estimating number of cells in a reaction

Answer 3

1. Glucose or oxygen consumption
2. Specific product: (hepatocytes monitor urea, fibroblasts produce collagen, general: lactate…yeast produces ethanol)

Question 4

Role of physical conditioning

Answer 4

1. SYNTHESIS & HIERARCHY: Physical forces have been shown to be potent regulators of cell physiology in vivo, and modulate ECM synthesis and organizations at various hierarchical levels- from molecules to whole tissue/organs
2. DIFFERENTIATION: Mechanically generated signals play a significant role in differentiation of progenitor cells into different lineages
3. ORGANIZATION: Effective means to improve the cell/tissue structural organization

Question 5

Design consideration for bioreactors

Answer 5

1. Definition of Stimuli: Most important
   (stretch, electrical stimulation, perfusion, growth factors)
2. Control of Cultural Variables: temp & pH
   (temp, pH, oxygen saturation)
3. Sensor Technology: latest developed technologies in the field
   (temp, pH, oxygen saturation)
4. Stimulation Protocol: Stretch protocol, etc.
   (feasibility testing, maturation & development, maintenance and sustainability)

Question 6

Scale up vs. Scale out

Answer 6

reduces the operator-dependent variable and ensures product quality
vs.
going from one to multiple