Bioreactors Flashcards
(25 cards)
What is the main purpose of a bioreactor in tissue engineering?
To support cell growth and tissue development by improving mass transfer and applying mechanical stimuli.
How do bioreactors support cell culture?
By providing nutrients, removing waste, and mimicking mechanical environments of tissues.
Why are mechanical stimuli used in bioreactors?
Most cells respond to mechanical forces (e.g., tension, compression, shear), promoting growth and differentiation.
What’s the advantage of mechanical stimulation over biochemical factors?
It’s often cheaper and avoids the high cost of recombinant growth factors.
List 3 common bioreactor designs
Spinner flask
Rotating wall vessel
Perfusion chamber
What is a spinner flask bioreactor?
A vessel with a central stirrer creating turbulent flow.
What are two pros and cons of spinner flasks?
✅ Simple, cost-effective
❌ Shear stress can damage cells, scalability is limited
How does a rotating wall vessel work?
It rotates to create low shear, microgravity-like conditions for cell culture.
Pros and cons of rotating wall vessels?
✅ Low shear stress
❌ Complex operation, limited oxygen diffusion in larger constructs
What is a perfusion chamber?
A system that perfuses media through a 2D/3D scaffold.
Pros and cons of perfusion chambers?
✅ Can mimic in vivo flow
❌ Complex and expensive, precise flow control is need to avoid high shear
What is co-culture and why is it important?
Culturing multiple cell types together to mimic real tissue environments.
What are the requirements of a bioreactor in this context.
Flow / media distribution
Co-culturing
Sterile/ impermeable
No intentional air bubbles
Mechanical stimulation
What mechanical forces can bioreactors apply?
Shear stress, tension, compression, bending, hydrostatic pressure.
What is the purpose of a “coffee plunger” system?
To apply shear and compressive stress in a vertical loading model.
What are some mechanical stimulation techniques?
Coffee plunger
Compression and perfusion
4 point bending
Rocker culture
Why use compression + perfusion in bone and cartilage engineering
Mimics bone and cartilage environments with dynamic load and flow.
What is four-point bending used for?
Uniform 2D stretching/compression to stimulate cell cultures.
Describe 2 approaches to mechanical stimulation of a 3D construct
- Pre-differentiate cells in 2D, stimulate, then implant them in vivo.
- Stimulate a 3D construct with cells already embedded.
What is a rocking platform used for?
To induce oscillatory fluid shear stress (FSS)
What are some signs of success in bone/ cartilage engineering
Improved mineral deposition, collagen, and stem cell growth.
What are microfluidic or “organ-on-a-chip” systems?
Devices with microchannels that replicate tissue environments for cell studies.
Benefits of microfluidics?
Small volume, high precision, dynamic control of fluids and gas.
What is “osteogenesis-on-a-chip”?
A microfluidic platform supporting bone cell growth via mechanical and chemical stimulation.
