MMM, Biomaterials II
MMM (3), Biomaterials II
MMM (3), Biomaterials II
Kartei Details
| Karten | 12 |
|---|---|
| Sprache | English |
| Kategorie | Technik |
| Stufe | Universität |
| Erstellt / Aktualisiert | 09.01.2019 / 09.01.2019 |
| Weblink |
https://card2brain.ch/box/20190109_mmm_biomaterials_ii
|
| Einbinden |
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advantages of drug delivery
- maintain therapeutic level of drug
- protection of drug and patient (less side effects)
- easy administration
- matching drug release profile to patients needs
- reach hard-to-reach areas (brain)
- implants do not have to be removed
Mab
Monoclonal antibody
Nib
inhibitor
polymer requirements for drug delivery
- safe for clinical use
- degrade into non-toxic products
- tunable degradation rates
- biocompatible
biomaterial challenges
- vascular devices clot blood
- metal implants corrode and leach ions
- implanted sensors encapsulate and fibrose
- contact lenses infect
- implanted valves calcify
- soft tissue implants fibrose, infect
encapsulation of implanted materials
infection after the implantation of a material leads to attraction of neutrophils, they make contact to the surface and induce an immune reaction. macrophages arrive and also fibroblasts. several macrophages then couple up in "Foreign Body Giant Cells FBGCs", they have multiple nuclei. The biomaterial gets encapsulated by fibers built from the fibroblasts.
anti-inflammatory materials
- anionic
- hydrophilic
- softer
- topologies around 1-2 microns
biocompatibility testing procedures
- extract test
- extraxt test: colony formation
- direct contact test
- indirect contact test: agar diffusion test
- indirect contact test: filter diffusion test
extract test: procedure
Test sample is given on a cell culture plate, the cells are able to degrade Tetrazole (yellow) into formazon (purple). the more purple the solution is after a while, the more active the cells are.
a 30% reduction in cell activity is considered as a toxicity and therefore is bad.
- short exposure time
extract test: colony formation
less cells in the culture, add medium and then observe how the culture has grown.
--> quantitative evaluation after colony formation
direct contact test
test sample is placed on a subfluent cell culture, 10% of the area of the culture must be covered. the test sample then diffuses. the dead cells are marked in red, the alive ones are marked in green.
- depending on diffusion rate out of material
indirect contact test
filter or agar on top, live-dead-assay
- low sensitivity due to layer.
