08 Anchorage vs Suspension cultures

Question 1

Bioreactor

Answer 1

• supports a biologically active envmt/ facilitating a microoorganism’s reproduction
  >biofermentor

Question 2

Growth culture considerations

Answer 2

• cell type
• optimal means of growth
• decisions in growth scale
• decisions in disposability
• bioreactor issues

Question 3

Anchorage dependent culture

Answer 3

• requires a solid substratum for growth
  >Adherent cell culture
• usually derived from stationary cells (liver,heart)
• attached to surface of vessel while growing

> animal, insect

Question 4

Suspension culture

Answer 4

• grows free-floating in media
• not attached
• cells exposed to media
• must be mixed/shaken

> animal, insect, bacteria, yeast

Question 5

Bioreactor issues:

Answer 5

• oxygen limitation
• shear damage
• metabolite toxicity
• nutrient limitation

Question 6

The common theme in each of these scale up methods is _______

Answer 6

finding a way to increase surface area

Question 7

Tissue Flasks

Answer 7

• Bottom (horizontal) section is chemically treated so cells have surface to adhere
• 50 – 650mL
• Monolayer of cells grows along ‘bottom’ of flask
• Cells removed by chemical treatment or by scraping

Question 8

Cell Factories

Answer 8

• Simplest form of scale up due to similarity with growth in flasks
• 200 – 8000mL
• Fixed together vertically and supplied with media (and air) via interconnecting channels at corners
• Difficulties in harvesting and expensive to use (single use)

Question 9

Roller Bottles

Answer 9

• Monolayer of cells is created around inner surface of the bottle
• 100 – 1000mL
• Main advantage is increased ratio of surface area to volume

Question 10

Hollow Fiber Bioreactors

Answer 10

• Bioreactor is composed of small hollow tube-shaped filters that are sealed into a sterile cartridge shell
• 2.5 – 150mL (limited volume)
• So if product is designed to be excreted by cells can extract that though the pores in the hollow fibers

Question 11

Microcarriers

Answer 11

• Small spherical beads act as a support for cells (100μm diameter)
• Cells grow in monolayer on surface of beads
• Difficult to monitor growth as cells must be trypsinized off first

Question 12

3D Cell Culture

Answer 12

• Scaffold to support cell growth
• Tissue cultures are very similar to cell types when in the body
• Better growth of complex tissue structures
• High yield relative to volume
• Very small scale (mostly performed in microplates), not readily upscaled

Question 13

Flasks

Answer 13

• Most common means of small scale growth
• 50 – 5000mL
• Normally grown in shaking incubator

Question 14

Spinner Flasks

Answer 14

• Simple, inexpensive means to grow culture
• 25 – 3000mL
• Also limited by oxygen exchange

Question 15

Wave Bioreactor

Answer 15

• Disposable bioreactor system (no cleaning, no sterilization)
• 1 – 500L
• Closed system, with limited access points for media addition/withdrawal, air filtration,
• Less prone to contamination, higher costs (materials)

Question 16

Bello Cell

Answer 16

• Fashioned after principle of a bellows
• 500mL bottles – one size, no available option for scale up
• Can collect cells or cell products
• Adaptable to many cell types
• Sterile, disposable, single-use

Question 17

Biofermentor

Answer 17

• Closed system with controlled access to chamber interior
• Industrial scale: 10,000 – 50,000L
• Standard bench top units from 500 – 10,000 mL
• Cooling and heating coils or jacket, sterile air inlet/addition by sparger, mixing by impeller