(PM3A) Tissue Engineering Flashcards
What is tissue engineering?
In vitro development of tissues/ organs
to replace/ support
injured/ defective body parts
What is the role of scaffolds in tissue engineering?
To act as temporary/ permanent artificial extracellular matrices
What is an ECM?
Extracellular matrix
What is an ECM comprised of?
Protein fibres
What is the role of an ECM?
Serves as a dynamic substrate to support tissue repair and regeneration
On what level do ECMs function, in SI units?
(nano, micro, milli, etc)
Nano to micro
What stages are there in tissue engineering before a tissue can be transplanted into a human?
(1) Cells taken from a healthy sample (biopsy)
(2) Monolayer cell culture
(3) Expanded cells
(4) Culture on a 3D polymeric scaffold
(5) Generation of a graft
(6) Transplantation into human
Which molecule are platelets comprised of?
Fibrin
A protein
What is fibrin?
A protein that comprises platelets
What can cause a chronic inflammatory response in a patient with tissue engineering?
Biomaterial is a persistent irritant
Can lead to chronic inflammatory response
What is an effect of scar tissue, regarding function?
Impedes function
What is biocompatibility?
Ability of a material to perform with an appropriate host response in a specific application
What are some important properties of an ideal scaffold in tissue engineering?
(1) Have an interconnected macroporous network for vascularisation, tissue ingrowth and nutrient delivery
(2) Template for 3D growth
(3) Mechanical properties similar to host
(4) Bond to the host tissue without the formation of scar tissue
(5) Resorb at the same rate as the tissue is repaired
(6) Influence the genes in the cells of the tissue to enable efficient cell differentiation and proliferation
(7) Be easily and cheaply produced (must be easily sterilised)
Define resorb.
Absorb (something) again
How many important properties of an ideal scaffold are there to remember, in tissue engineering?
Seven
What size should the macropores of an ideal scaffold be?
100 mcm
What size should the micropores of an ideal scaffold be?
10-50 mcm
What are micropores important for in scaffolds?
(1) Cell adhesion
(2) Diffusion of oxygen + nutrients
(3) Waste clearance
What are macropores important for in scaffolds?
(1) Cell infiltration
(2) Invasion of blood vessels
(3) Building of tissue layers
What are the types of material that scaffolds can be made from?
(1) Synthetic polymers
(2) Natural
(3) Synthetic calcium phosphate ceramics (CPCs)
Give two examples of synthetic polymers used for scaffolds.
(1) Chitosan
(2) Alginate
Give three examples of synthetic polymers used for scaffolds.
(1) Fibrin
(2) Collagen
(3) Elastin
Define polymeric.
of/ relating to a polymer
What is another name for fibrin?
Factor Ia
What is another name for Factor Ia?
Fibrin
Which enzyme is responsible for the production of fibrin?
Protease thrombin polymerises fibrinogen
What is soluble tropoelastin protein?
Contains glycine and valine + modified alanine
Forms elastin
What is a CPC?
Calcium phosphate ceramics
When are CPCs often used in tissue engineering?
Bone tissue engineering
What is osteoinduction?
Stimulation of new bone formation
What is the significance of CPCs in vivo?
Shown to promote bone growth in vivo
Recruit bone marrow stromal cells (BMSCs) to ectopic sites
Induces bone formation
What are BMSCs?
Bone marrow stromal cells
What are some difficulties to be achieved in successful tissue engineering?
Achieving suitable porosity while maintaining appropriate mechanical properties
How can vascularisation be achieved in tissue engineering?
Have an interconnected macroporous network in the scaffold
What does an interconnected microporous network achieve?
(1) Vascularisation
(2) Tissue ingrowth
(3) Nutrient delivery
What is tissue in growth?
Ability of the body to incorporate an implanted mesh
