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Flashcards in L1-4 Deck (38):
1

List some major used of biomaterials.

Replacement- dialysis
Healing - sutures
Improve function - contacts
Correct function - spinal rod
Cosmetic correction - silicone boobs
Replace rotten - dental amalgam
Replace dead - skin

2

What are the 5 main issues with biomaterials?

Biocompatibility
Mechanically appropriate
(Rigid for bones, flexible for tendons)
Stability appropriate
Machinability
Sterilisability

3

Two degrees of biocompatibilities, what are they?

Integrated fully - strong attachment to tissues

Inert- just chill except physical presence

4

Examples of biomaterial use according to appropriate degradation time?

S/mins: surgical instrument
Hours: hemodialysis membrane
Day/weeks: sutures
Life: joints

5

Outline development of biomaterials in terms of generations and give example for each.

First generation: gold fillings, titanium alloy dentals

Second generation: bioengineered materials like bioactive glasses and ceramics, biodegradables

Third: state of the art techniques with regenerative medicine aka tissue engineering
Grow ear on a rat?!

6

Basic outline of tissue enginnering?

Cells from host
monolayer cell culture
Expand culture can use scaffolds, causing cell integration

Generate a graft
Implanted to host

7

Define

Cell culture
Tissue culture
Explant culture

Cell: in suspension
Tissue: intact structures maintained outside body

Explant: in between the two types

8

Compare the two main classes of cell culture, primary cells and Cell lines.

Primary cells: derive from tissues directly. HAYFLICK LIMITED

Cell lines: grow continuously, originally from primary cells but immortalised. NO HAYFLICKS

9

Which cells can grow in suspension?

Blood cells
Blood cell progenitors

10

how can you obtain cell suspension from tissue fragment?

Use Trypsin (proteolytic enzyme)

11

Describe serial culture.

Confluent monolayer cells broken by trypsin

Cells round up and detach

Each cell seeded into different vessels

12

Explain Explant culture z

Tissue fragments seeded in vessel
Cells grow out of explants
Form confluent monol


*contains mixture of cells ofc*

13

What are some crucial factors for cell culture in serum?

ITS: insulin transferrin selenium
attachment factors: Vitronectin, fibronectin

GF: IGF EGF FGF

Other hormones or steroids for proliferation

14

How can we use ECM in cell culturing?

Anchorage of cells
Providing scaffold during growth
Physical barrier to shape cells or orientation

Can aid cell deformation

15

What is SF/HGF?

Scatter factor/ hepatocyte gf

A plasminogen like protein
Secreted by fibroblasts
Binds to C-Met Oncogenic tyrosine kinase receptor

Act on epithelia, endothelia, muscles, bloods

Binds to receptor- dimerise- auto phosphorylation - morphogenic change

16

What happens to the cell when cultured on :

Flat surface
3D ECM gel

Flat surface causes Scattering of epithelia

3D ECM gel causes epithelia to form fluid-filled hollow cysts. These are stimulated if we want to make branching tubules.

17

How does external factor influence scattering?

Greater scattering if culutred on collagen1 than in serum.

Scattering depends on what cell and what attachment factors are present

18

What is anchorage dependence?

Cells require adhesion to support to be able to fully respond to GFs.

19

Contact inhibition of Locomotion?

Is where cells make contact there is paralysis and the other side cell spreading is promoted, moves away from each other

20

Define contact guidance.

Effect of the layout of local environment on cell shape and migration.

21

Which case causes more spread out cell?

Large radius curvature surface
Or small radius c

Large radius curvature, cells don’t like to bend

22

Processing of Microphotolithography

Substrate coated with photosensitive plastic

Cover with patterned mask
Exposed to light

Exposed area chemically changes to be more sensitive for removal

Dissolve in developing solution to remove that

Substrate exposed are etched

Photoresist removed completely
Gives you topography

23

How does ;Neurites, Fibroblasts
And Epithelia
Respond to 10micrometer topography in terms of alignment?

Neurites ignores it

Fibrob shows GRADED response

Epithelia NON GRADED response in alignment
But graded response in cell elongation

24

How do you create hydrophobic micropatterns?

Substrate covered with desired patterns then exposed to ALKYLCHOROSILANE

reacts with OH on the substrate causing covalent bonding of the hydrophobic groups

Exposed area becomes poorly adhesive

25

We can control Neurites growing using micropatterns. Use Dorsal root ganglion to explain thisz

Dorsal root ganglion cells are
Pseudounipolar in vivo
Multipolar in vitro
Bipolar on Laminin

26

On narrow micropatterned tracks, narrow myotubules formed. What can you see on Wide micropatterned tracks?

No no wide myotubes. Still narrow.

27

Define nanoparticle.

Structure with at least one dimension of 100nm or less

28

List a natural nanoparticle and a man made.

Soot or volcano ash

Diesel exhausts

29

Name some carbon based nano materials.

FULLERENE
CARBON NANOTUBES

30

What metals and metal oxides are used as nanomaterials?

Gold and silver

TiO2 cosmetics πŸ’„
ZiO2 suncreameee β˜€οΈ

31

Why is Graphene the don of the don?

Thinnest
Strongest
Electrical conductor
Super heat conductor πŸ”₯
Incredibly dense
Transparent

32

Why are carbon based nanoparticles good for drug delivery?

Many different shapes : rod, spheres (FULLERENE), spiral...

Very stiff and strong
Good electrical conductor
Thermal stability πŸ’ŽX2

33

Where do we use carbon nanotubes for?

Engineering, construction, cosmetics...

34

List uses of silver and its appliance from that.

Antibacterial - add to cost venous catheters and use in bone cement
Healing promotion- wound dressings

Cauterization: to stop epistaxis
Inflammatory: pleurodesis to prevent lung collapsing

Regenerative : ulcer treatment and cosmetics

35

How is gold used for Arthritis?

Macrophage engulfs gold
Becomes anti inflammatory

36

Good and bad tings about AFM

ATOMIC FORCE Microscopy

:) wide range of cells, can use on living cells

:( unreliable for eukaryotic because tips can damage.

37

Why does Scanning Ion Conductance Microscopy not cause cell damage?

What are other benefits?

Electrode measurement of current maintains the tip constantly distant from cell surface
But can damage tall structures

High resolution
Can study changes in topography during stimulation

Cell vol and height measured
Study cell dynamics

38

Tell me a limitation of SICM. How can we solve this?

Limited to a flat surface specimen.

Hopping probe ICM
Probe hops to catch every level!