Tissue engineering

Question 1

what is the goal of tissue engineering?

Answer 1

replace/improve biological tissue and their functions

different tissue artificially made/formed into bone/vessels/bladder/muscle

Question 2

what does tissue engineering consist of

Answer 2

1. scaffold - supporting tissue formation in 3D space
2. living cell/tissue
3. control over growth factors
4. culturing - maintain oxygen/pH/humidity/temp/nutrients/osmotic pressure
5. biocompatible/biodegradable and low immunogenicity

Question 3

what is the general process for tissue engineering?

Answer 3

1. remove cells from the body e.g. stem cells
2. cell expansion in culture
3. seed cultured cells on nano-fibrous scaffolds in culture media
4. leave in culture to form functional tissue
5. re-implant the engineered cell-scaffold construct to the injury site

Question 4

what must the scaffolds must do?

Answer 4

to recapture the extracellular matrix (ECM) and microenvironment to match where the injury site is

Question 5

what are important factors of scaffolds?

Answer 5

1. Biocompatibility, biodegradability, and low immunogenicity
2. provide mechanical support during the spatial tissue organisation of cells
3. maintain mechanical integrity
4. accelerate tissue formation
5. composed of nanoscale fibres = better tissue compatibility
6. potency of biomimetic fibres
7. mimic ECM
8. increased SA
9. support cells

Question 6

why is a scaffold important?

Answer 6

leads to sufficient neovascularisation, adequate oxygen supply, and mechanism for waste disposal

Question 7

what are the advantages of metallic nanostructures?

Answer 7

Optical adjustability, electrical conductivity,
surface chemistry, ease of fabrication

Question 8

what are engineered cardiac patches used for?

Answer 8

treating damaged heart tissues after a heart attack

Question 9

how are engineered cardiac patches made?

Answer 9

biological polymers - alginate /synthetic polymers
such as poly(lactic) acid (PLA)

Question 10

what are engineered cardiac patches made of ?

Answer 10

metallic nanostructure

Question 11

what are the disadvantages of engineered cardiac patches?

Answer 11

poor conductivity of these materials limits the ability of the patch to contract strongly as a unit

Question 12

what does gold nanowires incorporated into alginate scaffolds show?

Answer 12

To bridge the electrically resistant pore walls of alginate

To improve electrical communication between adjacent cardiac cells

The gold nanowires have also enhanced the tissue thickness and alignment

The cells in this tissue have shown the ability to contract synchronously corresponding to electrical stimuli

Question 13

name material used in metallic nano materials in tissue engineering?

Answer 13

gold, silver and titanium/Ti6Al4V

Question 14

when are carbon nanotubes used in tissue engineering?

Answer 14

cardiopulmonary applications - catheters
neuronal tissue regeneration

Question 15

why are carbon nanotubes used in tissue engineering?

Answer 15

highly compatible with blood
chemically inert
neuronal tissue regeneration due to superior electrical conductivity = promote neurone attachment/growth /differentiation and long-term survival

Question 16

what CNTs combines with to enhance its strength and elongation capacity?

Answer 16

polyurethane

Question 17

what happens when CNTs are integrated into polyurethane?

Answer 17

enhance its strength and elongation capacity
anticoagulant properties

Question 18

why are engineered cells encapsulated?

Answer 18

1. prevent immune cells/antibodies from destroying
2. overcome existing problems of graft rejection
3. reduce the need for immunosuppressive drugs after an organ transplant to control side effects = reduce polypharmacy

Question 19

what are engineered cells encapsulated in?

Answer 19

polymeric semi-permeable membrane

Question 20

why are engineered cells encapsulated in a semi-permeable membrane?

Answer 20

influx of oxygen, nutrients and growth factors

Question 21

when is collagen used in tissue engineering?

Answer 21

in the ECM (Extracellular Matrices)
abundant mammal protein
to provide support to tissues - skin/cartilage/bones/blood vessels/ ligaments

Question 22

how are cells regrown?

Answer 22

3D bioprinting has been used