Blood-Material Interactions Flashcards
Week 7
How do you identify the macrophages in this image?
- size of macrophage
fixme insert annotated picture
What are two vital functions of macrophages?
- Recognize cells as ‘self’ or ‘not self’
- Phagocytosis (engulfing other cells)
What type of cell is a neutrophil?
Immune cell
What does the immune system do?
- Mobile
- Find bacteria
- Chemotaxis (movement of a cell/organism)
What are the 8 steps in the body’s response to injury?
- Injury
- Blood-biomaterial interaction
- Provisional matrix formation
- Acute (short-term) inflammation
- Chronic (long-term) inflammation
- Granulation tissue
- Foreign body reaction
- Fibrous capsule formation
True or False:
Surgery alone is an injury.
True
A fibrous capsule forms around an implant. Afterward, how does it integrate with the surrounding tissue?
It doesn’t become part of the tissue. It’s walled off.
What is the sequence of cell types in response to an implanted biomaterial?
- Neutrophils
- Monocytes
- Macrophages
- Fibroblasts and foreign body giant cells
- Myofibroblasts
What are the 5 stages of healing after a biomaterial is implanted?
- Biomaterial implantation
- Protein adsorption
- Macrophage adhesion
- Encapsulation
- Capsular contracture
see this picture for more information
What is the immune system doing during the homeostasis phase of wound healing?
Processes:
- Coagulation
Cells/Molecules/Tissues
- Platelets
- Fibrin
What is the immune system doing during the inflammation phase of wound healing?
Processes:
- Immune infiltration
- Debris clearance
- Pathogen killing
Cells/Molecules/Tissues
- Neutrophils
- MQ (Macrophages)
- Lymphocytes
What is the immune system doing during the profileration phase of wound healing?
Processes:
- Fibroblast proliferation
- Scar formation
- Collagen synthesis
- Angiogenesis
Cells/Molecules/Tissues
- Proteoglycan
- Fibroblast
- Collagen
What is the immune system doing during the remodeling phase of wound healing?
Processes:
- Epithelialization
- ECM remodeling
- Scar maturation/contraction
- Apoptosis
Cells/Molecules/Tissues
- Epithelium
- Endothelium
The homeostasis phase of wound healing lasts:
A. hours
B. days
c. weeks
d. months/years
A. hours
The inflammation phase of wound healing lasts:
A. hours
B. days
c. weeks
d. months/years
B. days
The proliferation phase of wound healing lasts:
A. hours
B. days
c. weeks
d. months/years
c. weeks
The remodeling phase of wound healing lasts:
A. hours
B. days
c. weeks
d. months/years
d. months/years
How do cells sense and interacts with a foreign object, such as an implant?
Protein interactions
Designing how proteins bind to the ________ controls how the body reacts to the implant
A. implant
B. cells
C. body
A. implant
True or False:
Blood-implant interactions regulate cell-implant interactions.
True
What are two biomaterial properties that regulate adsorption?
- surface hydrophobicity
- surface charge
What happens if you change an implant’s surface hydrophobicity?
- Dehydration of the surface and protein (H2O molecules are rearranged)
- Structural arrangements of proteins (2, 3, 4 structure)
What happens if you change an implant’s surface charge?
- Redistribution of charged groups
- Structural arrangements of proteins (2, 3, 4 structure)
What are five biomaterial properties that regular adsorption?
- Topology
- Composition
- Hydrophobicity
- Heterogeneity
- Potential
What is the effect of changing the topology property of an implanted biomaterial?
More texture means more surface area, which means more interaction sites.
What is the effect of changing the composition property of an implanted biomaterial?
Chemical groups will determine types of interactions with proteins
What is the effect of changing the hydrophobicity property of an implanted biomaterial?
Hydrophobic surfaces tend to bind to more proteins
What is the effect of changing the heterogeneity property of an implanted biomaterial?
Non-uniform surface properties leads to surface domains that can interact differently (*some +/- charges are rough/smooth)
fixme check this
What is the effect of changing the potential property of an implanted biomaterial?
Electrochemical potential - distribution of ions in solution and interaction with proteins
release to charge + protein shape + entropy
fixme check this
What are four protein properties that regulate protein adsorption?
- size
- charge
- hydrophobicity
- stability (structure)
What is the effect of changing the size property of a protein?
Big molecules have more sites for contact
What is the effect of changing the charge property of a protein?
Molecules with charge generally adsorb more readily
What is the effect of changing the hydrophobicity property of a protein?
Hydrophobic molecules adsorb to hydrophobic surfaces
like binds to like
What are two effects of changing the stability property of a protein?
- Less conformationally stable proteins can unfold more and form more surface contact points
- Molecules that unfold more rapidly can form contact points more rapidly
On this image, identify the regions where the protein will interact with the solid.
What is the vroman effect?
