Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Regenerative Medicine > Lecture 9 - Tissue Engineering 2 > Flashcards

Lecture 9 - Tissue Engineering 2 Flashcards

1
Q

What are the required cues for effective maturation of tissue in vitro?

A

O2 concentration, fluid flow, forces

These cues can be achieved using bioreactors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Name a type of bioreactor used in tissue engineering.

A

Rotary Cell Culture, Stirred Flask

Stirred flask - medium flowss over and through scaffold
Rotary cell culture - cells in free flow stimulating microgravity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the types of forces applied in bioreactors?

A

Tension, Perfusion, Compression

Reference: Courtney A. Powell, et al (2002) American Journal of Physiology - Cell Physiology.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the optimal bioreactive for cartilage?

A

Rotating wall

Static - necrosis seen at centre and deposition of matrix
Spinner flask - harsh shear forces so cell death seen at edges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the significance of the temporomandibular joint (TMJ) in tissue engineering?

A

Used as a model in tissue engineering studies due to difficulty in generating it in vitro

Approximately 25% of the population exhibits TMJ disorders.

Uses combination of natural scaffold, bioreactor technology, and cell biology to replicate TMJ with cells at physiological density.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the outcome of bioreactor culture in bone defect repair?

A

Increased cell proliferation and bone matrix formation in comparison to static.

Pateint-specific bone constructs a possibility.

Reference: Grayson, W.L., et al. (2010) Proc. Natl. Acad. Sci. USA.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a patient-specific application of bioreactor technology?

A

Creation of patient-specific bone constructs

Reference: Grayson, W.L., et al. (2010) Proc. Natl. Acad. Sci. USA.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define the concept of using the body as a bioreactor.

A

Using the body to provide the correct environment for tissue development

Involves chemical signaling and mechanical forces.

Scaffold inserted into host and body does the work.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What substance was injected to create an ‘in vivo bioreactor’ in a study?

A

Calcium alginate hydrogel

Injected between periosteum and tibia in rabbits.

Activates stem cells to differentiate into bone tissue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the advantages of acellular strategies over engineered tissues?

A

Designed to release drug cocktails, recruit specific cells, less expensive

Example: 30-year-old TB patient, Claudia Castillo - end-stage bronchomalacia (weaking cartilage).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What was the method used in bronchial repair involving a donor trachea?

A

Seeded with epithelial cells and MSC-derived chondrocytes from the pateint

Bespoke bioreactor
Hydordynamic forces and liquid/air

Reference: Macchiarini, P., et al. (2008) Lancet.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What was the outcome of the bronchial repair procedure after 4 months?

A

Immediate restoration of functional airway, normal appearance and mechanical properties at 4 months

No donor antibodies & no immunosuppressive drugs = ‘biological scaffold’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the complexity challenge in tissue engineering?

A

Tissues are extremely complex, involving 3D structures, vascular networks, and nervous connections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a key component in the application of heart blood vessel repair?

A

SMCs on polyglycolic acid mesh with pulsatile flow 5% distension to stretch mesh and cells can experience mechanical force

Reference: Xu, Z.C., et al. (2008) Biomaterials.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What effect does pulsatile/dynamic culture have on blood vessels?

A

Increased strength and more ECM deposition

Reference: Xu, Z.C., et al. (2008) Biomaterials.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Fill in the blank: The application of _______ is crucial for cardiac muscle development in heart attack repair.

A

Contractile cardiomyocytes

Cells seeded onto scaffold, expansion takes place and contractile cardiomyocytes generated.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the primary use of donor organs or tissues in engineering?

A

To replicate structural complexity

This approach could potentially utilize xenogeneic tissues.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which publication discusses the engineering of livers?

A

Uygun, B.E. et al (2010) Nature Medicine, 16, 814-821

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What process was used to decellularize the liver in the study?

A

SDS treatment over 72 hours

Vascular network remains intact.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What remains intact after the decellularization of the liver?

A

Vascular network

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is a significant challenge in tissue engineering related to cell survival?

A

Cells need to be within ~200 µm of a blood vessel to survive

Tissue engineered constructs need capillaries which integrate with the patient.

22
Q

What are three proposed solutions for vascularization in tissue-engineered constructs?

A
  • Seed scaffold with endothelial cells (randomly or pre-formed channels)
  • Incorporate VEGF into scaffold (promotes angiogenesis)
  • Build scaffold around vascular bed ex vivo
23
Q

What is the ideal solution for promoting vascularization?

A
  • Scaffold (human platelet lysate)
  • Signals (human platelet lysate)
  • Cells (ECFCs)

Incorporarted into a bioactive construct

24
Q

Name a type of cell that can form blood vessels when stimulated.

A

Endothelial Colony Forming Cells (ECFCs)

25
What are some key proteins found in platelets that promote blood vessel formation?
* PDGF * VEGF * FGF-2 * EDF ## Footnote ECFCs can also form blood vessels when stimulated.
26
What characteristics should an ideal scaffold have for tissue engineering?
* Biodegradable * Adhesive * Non-animal origin * Affinity to GFs * Multifactorial * Inexpensive
27
What is one of the challenges of vascularization in tissue engineering?
Integration with the host’s blood vessels
28
Fill in the blank: The engineered liver study by Uygun, B.E. et al was published in _______.
Nature Medicine
29
True or False: The ideal scaffold for tissue engineering should be easy to obtain and support the formation of a vascular network.
True
30
What is a bioactive construct in the context of tissue engineering?
A construct that can promote biological activity, such as cell integration or growth
31
What is the role of collagen in tissue engineering?
To provide structural support and promote cell adhesion
32
What is the significance of endothelial lineage cells in vascularization?
They are proliferative and support the formation of a vascular network
33
What does the term 'ex vivo' refer to in the context of tissue engineering?
Experiments or processes performed outside a living organism
34
What is 3D bioprinting?
A technology that combines cells and biomaterials to create tissue-like structures. ## Footnote 3D bioprinting is used for applications like organ and tissue regeneration.
35
What are some commercially available bioprinters known for?
Printing cells and scaffold materials separately. ## Footnote Examples include various models available from companies like Allevi.
36
What are some approaches to 3D bioprinting?
* Chemical crosslinking * Physical interactions * Coaxial & microfluidic approaches * Support bath ## Footnote These methods are essential in the formulation and printing of bioinks.
37
What are two advanced 3D printing techniques mentioned?
* Digital light processing (DLP) * Stereolithography (SLA) ## Footnote These techniques are used for high-resolution printing.
38
What are some challenges faced in 3D bioprinting?
* Cell density * Resolution * Vascularization * Innervation * Mechanical integrity ## Footnote Addressing these challenges is crucial for the advancement of bioprinting technologies.
39
List five body parts that can be made with 3D printers.
* Blood vessels * Heart valves * Skin * Liver cells * Bionic ear ## Footnote These advancements highlight the potential of bioprinting in regenerative medicine. Cartilage can also be made.
40
What significant achievement has been made in automated skin generation?
100 cm² in just 35 minutes postgrafting on immunodeficient mice. ## Footnote This process shows promise for therapy and industrial applications.
41
What progress has been made in 3D bioprinting for skin?
Great progress in scaffold design, bioreactors, and the use of stem cells. ## Footnote These advancements have improved the potential for skin regeneration. Presence of basal lamina and stratum corneum.
42
What types of tissues and organs have been implanted into patients?
Currently comparatively 'simple' tissues and organs. ## Footnote More complex structures still face significant challenges.
43
What are the main challenges ahead for 3D bioprinting?
* Vascularization & anastomosis * Innervation and synaptogenesis * Arrangement of multiple cell types in complex 3D patterns & high resolution * Regeneration ## Footnote These challenges need to be addressed to enable the printing of complex organs.
44
Fill in the blank: 3D bioprinting has great potential but is currently limited to _______.
[comparatively 'simple' tissues & organs]. ## Footnote Complexity in tissue structure remains a barrier to full implementation.
45
What are the disadvantages associated with bronchial repair using tissue engineering?
* Lack of functional epithelium can lead to infection, inflammation, and stenoisis formation * Mechanical and vascular challenges - may not be structurally strong enough and poor blood supply can lead to tissue death Clinical failures: * Paolo Macchiarini performed first synthetic organ transplant * Out of 9 patients recieving the synthetic trachea, 7 died and the other 2 had their removed
46
Different applications of tissue engineering in heart repair
* Heart valves * Blood vessels * Cardiac muscle
47
What effect does platelet lysate have on existing blood vessels?
Causes the outgrowth of blood vessels (stimulates growth from existing blood vessels)
48
What potential does combining platelet lysate with ECFCs hold?
Potential to offer ready made, vessel-containing scaffold for engineering many tissue types ## Footnote Growth factors in gel will stimulate pateints existing vessels to integrate. All materials are from the patient, so no rejection or disease transmission problems.
49
What is the top-down approach?
Involves seeding cells onto a pre-fabricated scaffold, which mimics the tissue's shape and size, allowing cells to grow, proliferate and form a new tissue construct.
49
What is the bottom-up approach?
Involves constructing tissues by assembing smaller, functional building blocks (such as cells or micro-tissues) into larger, more complex structures.
50
What are the different types of 3D bioprinting approaches?
Droplet bioprinting Laser bioprinting Extrusion bioprinting ## Footnote Droplet based = discrete droplets of bioink onto substrate to form 3D strucutre Laser = laser beam to transfer biological material from a donor layer onto a receving substrate Extrusion = nozzel to extrude bioink onto a substrate, forming a 3D structure layer by later

Regenerative Medicine (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions