exam 3 Flashcards
1
Q
actin filiments goes with?
A
motor clutch mechenism
2
Q
cell receptors do what?
A
cell surface specilization, interface with biomaterials
3
Q
necrosis
A
uncontrolled cell death
4
Q
apoptosis
A
“programed” (aka by design) cell death
5
Q
list the three types of whiite blood cells that are assosiated with inflammatory cell infiltration
A
PMNS, monocytes, lympocytes
6
Q
monocytes differentiate into what?
A
macophages
7
Q
mast cells
A
assosiated with acute inflamation, found in connective tissue (local cops)
8
Q
cytokines
A
secreated factors that affect cells
9
Q
lymphocytes
A
chronic inflammation, fight infections and destroy foreign substances
10
Q
does the protein layer form before or after biomaterial interacts with host cells
A
before
11
Q
what do absorbed proteins on a biomaterial do
A
modulate host inflammatory cell interactions and adhesion
12
Q
three parts of the vroman effect
A
- protine absorbsion and desorbsion
- protine competative exchange
- protine exchange via transiet complex formation
13
Q
transition cascade from blood to foreign body giant cell
A
- monocyte in blood chemotaxis migration (movement and response to chemcial stimuli)
- monocyte transition to macrophage in tissue adhesion and differentiaion
- macrophage at the tissue/biomaterial interface signal transduction and activation
- foreign body giant cell on the biomaterial activity and phenotypic expression (ie. capsual formation, growth of new tissue)
14
Q
how to proteins arrive to the biomaterial
A
diffusion or convection bc they are dissolved in serum
15
Q
protines arrive to a biomaterial surface in order of what? (two)
A
- mollecular weight
- concetration and proximity
16
Q
five protein actions once they arrive to biomaterial surface
A
absoption, desorption, exhange with other proteins, denaturing, increase or deacrease in bioactivity
17
Q
time cascade of immune response to stimulus
A
- days: innate response. white blood cellse inclusing neutrophils
- weeks: adaptive response. lymphacytes (T and B cells) determine specific immune response with macrophaces
- months: resolution (tissue formation). fibroblasts trigger foreign body giant cell or regeneration
18
Q
cell interactions with foreign surfaces are mediated by what TWO things?
A
- intergrin receptors with absorbed adhesion proteins
- proteins can sometimes change their biological activity when they absorb
19
Q
what is immunomodulation
A
changing or instructing the innate and/or adaptive immune response for implants or tissue engineering purposes
20
Q
what is fibrosis?
A
a non-functional tissue scar
21
Q
three phases of cutaneous wound healing and timeline
A
- innate and adaptive inflamation (2-6 days). low collagen deposition
- tissue specific cell proliferation (6-12 days). medium collagen deposition
- growth and function maturaton (12 to 16 days). high collage deposition
22
Q
biological response is mediadet by what four items?
A
- innate and adaptive immune response
- autocrine and/or paracrine signals (auto = affect self, para = affect somone else)
- protein and cell interactions
- patient variability
23
Q
M1 macrophages
A
- pro-inflametory
- kill bacteria and fungi
24
Q
M2 macrophages
A
- anti-inflametory (reparative)
- wound repair and fibrosis
25
removal of WHAT is key to long term WHAT influx and causes WHAT if not done right
1. M1 macrophages
2. neutrophil
3. chronic inflamation
26
adheard cells on biomaterial surfaces releases WHAT
cytokines and chemokines
27
five domains of protein structure
1. hydrophobic
2. hydrophilic
3. positively charged
4. negativly charged
5. neutral (rare)
28
vroman effects are primarily driven by WHAT forces and why?
thermodynamic, to lower the overall system free energy (it wants to be neutral and reach equlibrium)
29
WHAT modifications of material WHAT are used to alter WHAT
1. physiochemical
2. surfaces
3. biological responses
30
three categories of biomaterial surface modifications
1. chemically or phiscally altering an existing surface
2. overcoating an existing surface with a different material
3. creating surface textures or patters
31
why are thin surface modifications deseriable
to keep the material's bulk functional properties the same
32
thick surface coatings are more subject to what?
delamination and cracking
33
at what point in the healing cascade do thin surfaces modify the path and why?
between protein absorption and immune cell response, it is easier to drive the response when you control the path early
34
why is delaminaiton of biomaterial surfaces bad?
you dont want loose material floating around the body bc it can trigger biological responses in the wrong areas
35
three methods used to resist delamination
1. strong covalent bonding between thinfilm and substrate
2. intermix substrate and thinfilm at interface zone for physical entrapment (ie IPN)
3. using a primer layer or incorperating functional groups for strong intermollecular adhesion
36
what is a nonfouling surface
a surface that resists the adsorption of proteins and/or adhesion of cells
aka: stealth surfaces that dont form biofilms
37
what is an exopolymer?
a bad biofim escreated by an organism (cells and pathogens)
they often grow to encapsualte the infection and made the infection nontreatable with drugs. they could fall of and bring the infection into other parts of the body
often requre surgery to adress... prevention>treatment
38
what type of surfaces tend to irriversibly absorb proteins and why?
hydrophobic bc of the proteins unfolding rate
39
list the principal significant adaptive respones of cells and what they are.
1. hypertrophy: cells get bigger
2. hyperplasia: more cells
3. atrophy: cells get smaller but not more plentiful
4. metaplasia: cells transform from one mature cell type to another
40
potential activities of a baseline cell population
1. grow bc of stem cells
2. natural cell death (apoptosis)
3. differentiation (change into different cells)
4. proliferation (create more of themselves)
41
what cells peak first during the inflametory response?
neutrophils (innate white blood cells that release signalling molicules)
42
immune response cascade to a biomaterial
1. nonspecific protein adhesion
2. monocyte adhesion
3. macrophage differentiaion
4. fusion and formation of foreign body giant cells (adaptive)
5. foreign body response
43
dendric cells fall into what immune response
innate (and adaptive?)
44
four categories of pattern recognition receptors
1. soluble complement receptors (transmembrane)
2. membrane-bound phagocytic receptors (engulf large particles)
3. membrane-bound signaling receptors
4. cytoplasmic signaling receptors
45
what do natural killer cells effect?
visus infected cells
46
what are antigens?
molecules that induce a specific immune response
control the adaptive immune response
47
T cells
lymphocytes
produce cytokines to orchestracte cell activities (feedback control system), and directly kill infected cells
48
B cells
lymphocytes
surface receptors work as membrane bound antibody (differentiate into plasma cells to secrete antibodies)
49
four factors of biocompatability
1. toxicology
2. reactions to products from extrinisic microbiological organisms colonizing on the biomaterial
3. mechanical effects
4. interactions with the enviornment
50
what is toxicology?
effects of material LEACHING from biomaterials (ie. ions)
absence of toxicity is not evidence of saftey
51
what is the goal of animal modaling?
to determine the saftey and efficacy of devices prior to human clinical trails
52
three Rs of animal modeling
1. replacement (dont use one if you dont need to)
2. reduction (use as few as possible based on the statistics)
3. refinement (its a step to a bigger human medical application) (use comp methods for refinement before animal models)
53
design criteria pyramid vertices for tissue engineering biomaterials
1. cells
2. biomaterials
3. biomechanical stimuli
4. mechancial stimuli
54
three FDA categories for biomaterial products
1. devices
2. drugs
3. biologic
55
what is an FDA 501(k) for
FDA approval of a device based on an already aproved predicate
based on non-inferiority (of mechanics, architecture, and cellularity)
56
list FDA premarket submission options
- 501(k)
- PMA (pre market aproval)
- de novo (new but low or moderate risk)
- humanitarian device exeption (high risk for rare conditions)
57
you need to have resonable assurance of BLANK and BLANK for BLANK and BLANK to get FDA aproval
1. saftey
2. effectiveness
3. function
4. design
