9. Scaffolds for Biological Tissue Reconstruction Flashcards
What is the tissue engineering triad?
Bioscaffolds + cells + growth stimulating signals
What is the function of bioscaffolds?
To mimic ECM
What are the 5 broad functions of ECM?
1) Structural support and physical environment for cells to grow
2) Provides structural/mechanical properties
3) Provision of bioactive cues
4) Acts as reservoir of growth factors
5) Provides a changeable environment to allow for events such as remodeling and neovascularisation
What are the three layers of ECM?
Fibrous layer
Cellular layer
Dense layer
What are the 4 important scaffold properties?
1) Architecture
2) Tissue compatibility
3) Bio-activity
4) Mechanical properties
What does architecture encapsulate?
Void volume
Porous
Biodegradable (degradation matching neo tissue formation)
What characteristics of tissue compatibility does a scaffold need to exhibit?
Cells need to grow and differentiate
Scaffold and products must be non-toxic
What characteristics of bio-activity does a scaffold need to exhibit?
Able to interact with cells to regulate activities
-Via topography or exogenous molecules
What mechanical properties does a scaffold need to exhibit?
Shape and stability
Similarity to host tissue
- Important for cell differentiation
What are the 4 main approaches to scaffold design?
- Pre-made porous scaffolds for cell seeding
- Decellularised ECM
- Cell sheets with secreted ECM
- Cells encapsulated in self assembled hydrogel
- Combination Scaffolds
What are the two “sources” of porous scaffolds?
a. Natural
b. Synthetic
What are the 3 main sources of natural scaffolds?
Autogenic
Allogenic
Xenogenic (different species)
What are the advantages of natural scaffolds?
Excellent biocompatability
Good cell attachment
What are the disadvantages of natural scaffolds?
Limited physical and mechanical stability
What are some sources of synthetic scaffolds?
Inorganic - Glass + ceramics etc
Organic - Polypropylene, nylon, teflon, polymethylmethacrylate