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The Need for Nanomaterial Evaluation in a Physiologically R The Need for Nanomaterial Evaluation in a Physiologically R

The Need for Nanomaterial Evaluation in a Physiologically R - PowerPoint Presentation

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Uploaded On 2016-11-28

The Need for Nanomaterial Evaluation in a Physiologically R - PPT Presentation

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

dynamic vitro aunp vivo vitro dynamic vivo aunp aaf system flow systems cell characteristics conclusions nano bio unique deposition

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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