Flashcards in L1-4 Deck (38):
List some major used of biomaterials.
Healing - sutures
Improve function - contacts
Correct function - spinal rod
Cosmetic correction - silicone boobs
Replace rotten - dental amalgam
Replace dead - skin
What are the 5 main issues with biomaterials?
(Rigid for bones, flexible for tendons)
Two degrees of biocompatibilities, what are they?
Integrated fully - strong attachment to tissues
Inert- just chill except physical presence
Examples of biomaterial use according to appropriate degradation time?
S/mins: surgical instrument
Hours: hemodialysis membrane
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?!
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
Cell: in suspension
Tissue: intact structures maintained outside body
Explant: in between the two types
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
Which cells can grow in suspension?
Blood cell progenitors
how can you obtain cell suspension from tissue fragment?
Use Trypsin (proteolytic enzyme)
Describe serial culture.
Confluent monolayer cells broken by trypsin
Cells round up and detach
Each cell seeded into different vessels
Explain Explant culture z
Tissue fragments seeded in vessel
Cells grow out of explants
Form confluent monol
*contains mixture of cells ofc*
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
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
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
What happens to the cell when cultured on :
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.
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
What is anchorage dependence?
Cells require adhesion to support to be able to fully respond to GFs.
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
Define contact guidance.
Effect of the layout of local environment on cell shape and migration.
Which case causes more spread out cell?
Large radius curvature surface
Or small radius c
Large radius curvature, cells don’t like to bend
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
How does ;Neurites, Fibroblasts
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
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
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
On narrow micropatterned tracks, narrow myotubules formed. What can you see on Wide micropatterned tracks?
No no wide myotubes. Still narrow.
Structure with at least one dimension of 100nm or less
List a natural nanoparticle and a man made.
Soot or volcano ash
Name some carbon based nano materials.
What metals and metal oxides are used as nanomaterials?
Gold and silver
TiO2 cosmetics 💄
ZiO2 suncreameee ☀️
Why is Graphene the don of the don?
Super heat conductor 🔥
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 💎X2
Where do we use carbon nanotubes for?
Engineering, construction, cosmetics...
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
How is gold used for Arthritis?
Macrophage engulfs gold
Becomes anti inflammatory
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.
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
Can study changes in topography during stimulation
Cell vol and height measured
Study cell dynamics