Kristen K Comfort Department of Chemical and Materials Engineering University of Dayton Defining the Nano bio interface Nano Bio interface dynamic physicochemical interactions kinetics and thermodynamic exchanges between nanomaterials NM surfaces and biological ID: 494616
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Slide1
The Need for Nanomaterial Evaluation in a Physiologically Relevant Model: Connecting Environmental Variables and NM Behavior to Toxicological Responses
Kristen K. Comfort
Department of Chemical and Materials Engineering
University of DaytonSlide2
Defining the Nano-bio interface
Nano
-Bio interface
= dynamic physicochemical interactions, kinetics, and thermodynamic exchanges between nanomaterials (NM) surfaces and biological components
Influenced By:
Determines:Slide3
motivation
Tremendous advances have been made in NM characterization, synthesis, and dosimetry
Parallel progress in biological models
needs to be developed and implementedLong term goals:Generate in vitro models that mimic an in vivo systemImprove predictive modeling of NM-behavior and bioresponses
Design accurate, high-throughput in vitro systemsSlide4
In vitro vs in vivo systems
in vitro
in vivo
Advantages:
Simplified model
Lower cost
Rapid assessment/ High-throughput capabilities
Can
explore mechanistic response
Cell line specificity
Advantages:
Complete physiological response
Inclusion of immune/inflammatory systems
Disadvantages:
Difficult to extrapolate to human system
Applicability is dependent on design
Disadvantages:
Ethical concerns – Europe is phasing out
High cost
Time requirements
Dosimetry and distribution concerns
Difficult to puzzle out NM mechanismsSlide5
In vitro vs in vivo systems
in vitro
in vivo
Current Limitation:
Poor
correlation
Need to improve in vitro models to bridge this gapSlide6
Let’s examine a tissue/organ system
What are its unique characteristics?
1) 3-DimensionalSlide7
Let’s examine a tissue/organ system
What are its unique characteristics?
3-Dimensional
Comprised of multiple cell types
(hepatocytes, endothelial,
Kupffer
)Slide8
Let’s examine a tissue/organ system
What are its unique characteristics?
3-Dimensional
Comprised of multiple cell types
(hepatocytes, endothelial,
Kupffer
)
Physiological fluid
Interstitial fluid or secreted bileSlide9
Let’s examine a tissue/organ system
What are its unique characteristics?
3-Dimensional
Comprised of multiple cell types
(hepatocytes, endothelial,
Kupffer
)
Physiological fluid
Interstitial fluid or secreted bile
Dynamic environment
Connected to the CVSSlide10
Primary goals…
To transform this:
Into something that is more representative of:
(1)
(2)
Which will lead to augmented in vitro applicability:
Increased
Correlation & Predictive ModelingSlide11
Experimental resultsSlide12
Study approach
Target system: Alveolar region
Model contains:
Human alveolar epithelial cellsArtificial alveolar fluid (AAF)Dynamic movement60 nm tannic acid gold nanoparticles (AuNPs)CharacterizeEvaluate nano
-bio interfaceSlide13
Dynamic flow
Introduced to the cell culture system through use of a peristaltic pump
Tubing was inserted into lid of 24 well plate
Each well was singularly connected, producing unilateral flow across the surfaceTarget volumetric flow rate was selected:Velocity in tubing = 0.2 cm/s (capillary rate)Velocity across cells = 0.003 cm/s (diffusion-based rate)Slide14
Environmental influence on cell morphology
A549 cells cultured with:
M
edia, staticAAF, staticMedia, dynamicAAF, dynamic
Conclusions
:
Dynamic flow induced elongation
AAF causes curvature
BOTH are seen in vivoSlide15
AuNp characterization
Primary size (nm)
65.1
± 5.3
Agglomerate size (nm)
74.8
± 4.6
Zeta potential
(mV)
-31.8
± 0.9
Ionic dissolution
(%)
0.8
± 0.5Slide16
AuNp characterization
Conclusions
:
Exposure to AAF significantly altered
AuNP properties and behavior.Slide17
Aunp Deposition
Deposition = percentage of administered NPs that are bound to the cell surface or internalized
The deposited dose has been strongly correlated to cytotoxicity
Conclusions
:
In media: dynamic flow reduces deposition
In AAF: deposition is unchanged due to sedimentation of large agglomeratesSlide18
Aunp internalization
TEM images of
Media, static
AAF, staticMedia, dynamicAAF, dynamic
Conclusions
:
Increased AuNP
number with AAF
AAF/dynamic – no internalizationSlide19
Nano-bio interface
Conclusions
:
Cells maintained altered morphology
Increased
AuNP
number with AAFSlide20
Take away message
It is possible to modify traditional in vitro systems to more closely mimic in vivo models
We introduced dynamic flow and biological fluids
NP characteristics and behavior are strongly dependent upon the surrounding environmentThis has been linked to bioresponsesTherefore, modified in vitro systems allow for identification of novel responses previously unobtainable.
Bridging the in vitro – in vivo gapSlide21
Thank you