First of all I'd like to take
a moment to really thank God for

the war me with Haitian to join
the fence forum at Georgia Tech.

And indeed it is my pressure to serve

it is my great pleasure to have such
a opportunity to really discuss and

important research in the area of
this emerging area of nanotechnology.

That is development of a safe and
biocompatible national platform.

As was any new technology.

I believe that it's very important
to understand implications of

environmental health and

safety issues with an ultimate goal to
mitigate the risks in the workplace and

to promote positive perceptions from the
general public as you guys sitting here.

Well I think there are two
knowledge is around us the most

popular product consumer product
is this sunscreen and more

than three hundred sunscreen containing
single oxide and titanium particles.

And the automobile industry this
catalytic converters going Annele.

As you can see that you can really by
using I mean these these Comeau to rely on

the new particles of plant the rhodium and
palladium to just the cold air

on the surface to promote to speed up
chemical reaction for pollutes and

to create one pot sic emissions by using
in a particles little material is needed

to create the same surface area across
the ceramic substrate in the commode or

carbon nanotubes have the strongest
strength to weight materials.

Of any you know materials and

researchers are using carbon
nanotubes to combine carbon and

shoes with other materials into composite
to build this light weights race craft.

However there is an issue
about toxicity of these nano

carbon in the tubes that raises
an important question about

whether they are safe to use or
not because it is so easy to in hell.

The Continental body.

Recently soon and wires are being
developed to make this flexible.

Touchscreen units for smartphones.

And believe or not if you hop online and
Google measle gold you will find.

This on my shop is selling these color in
their particles as a dietary supplements.

For optimal health health.

All these strongly believe that the small
size of particles really can create

the surface areas to
maximize effectiveness.

In the research from and

nanomaterials have identify many new
applications seeing emerging areas.

And because they do have this unique
physical chemical and biological

properties and then a scale that would
not otherwise occur in the boat material.

For example gold and
OK just represent golden cages.

Go Hurrell gold boxes
was truncated corners.

These go in and
OK just has extremely large scattering and

absorption coefficient as such they are
finding the new applications unanimous and

as a highly effective counter and agent.

Conceptually you could
inject the going out of his

body where they can deliver a specific
anybodies to the cancerous cells.

As I mentioned before they have extremely
large scale coefficient as such.

You will be able to enable that
improve image and to identify tumors.

OK.

And the strong absorption characteristic
of these cages will help them

to really facilitate these
thermo therapeutic treatments

after localization of these tumors.

While go nanomaterials will find.

Different possibilities for
use in the nano medicine.

There is an issue that
have to be considered for

us to get it in regards
with the Nano toxicity.

Because the small size particles could
enter tissue cells organelles and

interact with biologic speed.

To induce toxicity for human health.

And as you can see that there is really
a very complicated steps when you

really Trink those particles your body.

If you ask me I read it to take it.

No I'm not so

I think that you know not of toxicology
is really a substitute of nanotechnology.

That is Emergent to the area.

And then toxic really refers
to study the interaction

between of interaction nanomaterials and
biological systems.

You really focus on the identifying
the unique relationship

between these physical and
chemical properties of materials and

their biological response and on your hand
and on the other hand a good understanding

of these properties of that you reveal
I mean ritual behavior really you

would provide a basis for accessing
toxicities of these nanomaterials for

use in the animal studies you were ideally
you identified bag best all the interest

in turn leading to develop these kind of
evil and you need to study this too far to

understand how these nano particles
really interact with molecules and

molecule level and these informations
really can provide a good basis for

assessment or
risk management on the animal trails.

And the clearly cannot stand alone
by themselves in the engineer and

scientists of world making materials and

try to understand those kind
of fundamental things and

the same time you have to work with
the other communities from the Madison to

understand what's the best consequence and
working together is really needed to

really promote this very important area
of research in two thousand and eight

national nanotechnology initiative really
published this article knowing it safe

is a central theme with lots of funding
agencies working together to support this.

This area.

And as the material scientists sitting
here are any national scientists if you

ask me Are you nervous about
the things you're doing.

Yes we always have
a degree of nervousness.

What kind of other public opinions about
how science are going to be unfolding

unfolding.

And most importantly I think that we
have to engage the general public to

really understand this kind of the issues
and complications to help them to develop

nanotechnology and if you ask me Are you
really scared of nanotechnology.

No because I think that whenever a new

whenever a new technology
starts to emerge.

You have to understand the safety
issues and evaluations.

So because this is very important step for
the product development cycles

as shown here and this thing is
just shows you the timelines and

those kind of pipelines associated was
the product development of agriculture

biotechnology and biopharmaceutical via
pharmaceutical products as you can see

that clinical trials and safety variations
always play significant role before

any new technology takes to the steps for
the commercialization.

So I think then a technology is
in the stage that we have to

really take serious consideration
of those kind of the things.

And in this talk I'm going to use two or
as a case analysis for

our investigation of
the implications of silver.

Environment and health issues
environment and safety issues and

Sue is a noble battle and you will be able
to find those kind of products Where's

mirrors and
photographic films in the marketplace.

And.

And interesting enough to violence is
a by active was sufficient concentration.

You will be it is ready to kill bacteria
us as a result sewer is a very good and

he microbial agent.

And these days people are used
souvenir particles to cold a bandage.

OK To create this coating of and
microbial layer with

a low dose release from the silver
ions to protective to prevent or

prevent protect the bacteria's for effect.

If Hubie by the same token you will
be able to find this nano socks and

send to watch for purchase.

So as those products of SUV products.

Proliferated in the marketplace.

We are deliberating a souvenir
of particles truly safe for use.

So I think that you know the previous two
speakers have covered this area very well

and we know that has become and
very effective and

few microbial agents and but.

Ionic Silvers is one of
the most toxic metals known to

those kind of aquatic organisms in
laboratory testing and you are going

to get those kind of communities to
oversee the solo and in the universe and.

And you know imagine.

Let's just say what really
happened if you really dump.

A put a pot of sewer nanomaterials
in your backyard where

you're growing this pumpkin plants.

And this is a simple The broad tree
illustration that has been done by a high

school student and what we did is we put
in the hydroponic systems and then we

try to monitor the growth of the behavior
of these pumping plants and we found that.

No problem if you use human and
wires with the diameter of fifteen and

really extremely long.

Noodles of spaghetti is not a problem they
won't be able to penetrate into the cell

and really create any damage on
the pence but on the other hand if you

start to use forty nanometer Schuman and
accused as shown here and

their families the pumping
plant got sick after a while or

so without Again this is really as
matter as it was a dose you used and

you can see that there are LOTS of
a greenish stuffing those kind of water

that probably perhaps
indicate that overdosed.

The things this pumping in print and

what we always what we also there
is that we cut the leaf and

cut the roots and digest in the asset and
use I.C.B.M.'s to see that the weather we.

Have identified any transport from
routes to beef Yes we found that.

So we know that it is
getting into the pen and

somehow perhaps blocked nutrition
pathways and just getting sick.

But this simple illustration demonstrate
that the toxicity of the understanding of

the interactions with biological systems
really matters with the shape the size and

those characterise of characters
of materials as such this work

has motivated a systematic study of the
sewer of those kind of poor relation of

physical chemical properties of soon and
particles as a as a function for

the growth in his vision of East cells and
specifically we

wanted to demonstrate that surface
chemistry really has a great importance to

really either provide a very
reliable toxicity evaluations or

find in approaches to meditate the risks
of Susan and part of course of toxicity

is specifically we use welcome coarseness
is based upon all senses to generate

those kind of the human and of structures
and we are able to maneuver and

control the sequels and nucleation steps
through either someone emic of kinetic

control to formulate different crystal any
of seeds from which they can photo grow to

make wires plates and cubes was the silver
crystal linearity of one one and

one more facets respectively and
the beauty to have a very good controlling

size and
shape really help us to understand

you know what really happens for

the interaction of these nano Suman and
structures and with biological systems and

in particular we're interesting
the role of size shape.

So if it's chemistry that includes
capping agent surface facet and

sample agent issues that can cause
toxicity on the enemy trails.

And again we use those kind of
routine characterization tools for

mythology characterize Asian and
dynamic like scan.

Systems for size distribution and
surface charge.

And I.C.B.M.'s for
elemental concentration and finally we

use You've even spectroscopy to monitor
the the unique optical properties

coming out from the super nano
structures and for simplicity and

also sometimes you don't have lots of
choices as material scientists and

collaborator suggest
that we should look at.

And it's and it's a simple system.

It doesn't take a lot of time to incubate
our growth of the east cells and

the interesting to see that you know for
the regular budding process.

What really happened if we really don't
those kind of the inner part of course

was the to see that if
there is any inhibit.

Vision in the growth of the cell.

And I want to see I want to show you
that these are the key images and

specifically where interesting undecisive
fact twenty five nanometers cubes.

Suman and wires and plates and.

So first of all before we start any
investigation we really want to

understand what is the impact from
the I R N A super ions that can

dissolve from the next to an endometrial.

Because this is important we all know that
the two ions they can kill the cells or

they can generate toxicity and so
we have been very careful study for

all the study for all those kind of
samples we have done a time dependent

dissolution of Sooner particle studies
using I.C.B.M.'s and we found that

the release is from zero point one to
zero point eight milligrams per liter.

And what we were there and what we did.

Next is to use the super nitrite two
to do the process of the assays and

we found that nothing has been hit so

that results in the case that the release
of the sewers coming out from

nanomaterials won't generate any impact
for the toxicity studies in the next.

And also it is very
important to really monitor

the mythology changing solution because.

You have to dry out the sample and

you know that what's going on with it but
you know most of times when you

think you'll be in the horror of
hosting the cell culture media.

Perhaps they were aggregates
aggregation is a key point.

So what we try to do is use U.V.

simple you give this to monitor to
characterize mythology institution.

And interesting enough pretty much for
the soon and these are the you even in

an acute sense fears as you can see
that through a simple you have this you

can really see a distinguishing
peaks between the cubes and spheres.

So if you can monitor those kind of
you even as you would all be able

to monitor the change of
the mythology in solution.

And this is definitely
is the case because so

we can cook those kind of superdelegates
and make two fears in the solution.

Under this high pressure high
temperature environment.

And we found that you see those kind
of peaks continuously shift from blue

as the mythology changes start
it from cubes to spheres losing

corners in specifically and eventually
ended up with the sewer Nanos fears.

So that just indicates that you
believe this is a sensitive approach

to characterize the mythology in solution.

And we have been very careful experiment
during the those kind of the analysis and

we always monitor the new Reavis to
make sure it is the single format on

their part across not looking
at aggregation of particles and

specifically previous results have
indicated size really make the impact on

those kind of the interactions between
the cell uptake and biological tissues and

we choose to back to solve cubes
to Starwars twenty five and

sixty and
it has been reported thirty is a sensitive

areas that can promote those kind of
toxicity of soon and particles and

this is the twenty milligram of
the concentration by weight.

And we found that P.V.P. control P.V.P.
is is kind of a polymer and

there is no if this is a controlled
experiment and clearly.

All of the size of particles and
just prolong it.

The prolong it for twenty five nanometer
cubes vs sixteen animated cubes.

And we also follow use the D L S to
really monitor if there is an aggregation

in the solution not we're
looking at a single particle.

So the results indicate that smaller
sized particles demat toxic it is and

this is consistent to previous
findings because as you can see

that smaller sized particles perhaps
it's much easier for them to

really penetrate into the cells and also
the smaller size the larger the surface

to surface to lot of Rachel's then
ultimately they are more reactive.

And then this is this.

We use capping agent P.V.P.

to really promote the growth from
one the old surface of the facet.

And as such we can make those kind are we
can make those kind of the Pates wires and

the cubes and such to and the cubes is
always called it with a thinly P.V.P.

and P.V.P. You know this coating of P.V.P.
you won't generate any

toxicities to the needle structure so
we know that they are safe.

OK so we're trying to understand P.V.P.

by reducing by finding a way to reducing
the coverage of peer review on the surface

to see what kind of rule purity is
plain for the toxicity evaluation.

So what we can do is we can
wash the Sioux and the cubes.

You know in the water the washing cycles
in the case that you remove the P.V.P..

Repetitively And
just to really just reduce the layer.

And we found that this is a this is for

twenty five nanometers we found
that the more washing steps.

The more toxicities you're
generate it that in the case that.

OK because now you have more
sewer surface is exposed to

those kind of the biological systems
then this is this makes sense.

OK But interesting enough we did
the same experiment for sixteen.

So another cubes and it's opposite.

Something is going on.

It's opposite.

It turns out that the more washed.

You apply to cubes and
they become less toxic.

So we carefully again we look at
the aggregation though our relation.

There we are specifically pay attention to
the surface charge in the cell culture and

we found that the surface charge
really changes as function of time.

That indicates that perhaps four
to six in any particles you

really capture something in the culture
medium and make them less toxic.

So this results really
indicates that you know.

Yes you can put a coating are part
of your human and particles.

You can make them less toxic but

on the other hand when you do those kind
of evaluation in cell culture you have to

think that there are possibilities for
outer those kind of the body

cues that can't attach to your systems
that can interfere your understanding.

So it is a complicated process.

And also we're very
interesting the shape and

surface facets impacts on the toxicity
of human and particles and

as I said was ability to make different
shapes and if you look at it.

I'm making them as the color of
orange is fretted when one and

a grain is fastened one all and

it is such a coincident you can do the
color in your prior Point presentation.

And invention.

You know you can see that for
the cubes majority of wall plates

exclusively won't one and
a wire is a mixture.

So what you can do is you can
again do the toxicity experiments.

And first of all we found that yes.

For all those kind of measurements
twenty five sixteen and

different science wires in place.

They all have a concentration dependent
on things spewed up for the toxicity.

If you look for into the details.

Plates.

They are the most toxic and all materials.

Then next is wires and cubes.

So if you look at I mean we can do
a simple calculation of surface to volume

ratio and mass and in fact that still in
the cubes they are the ratio is the Lord.

First and they are the lightest in weight.

So you magine that
the reactivity should be higher

because they can easily get into the cells
or they can easily mobilize those and

the reactivity should be large for
this one and cubes.

But this conclusion is
totally opposite and

from what we are observed to without a
cube they are the least toxic and what we

believe is that we believe that the the
facet really pacing point to over there.

When when one is the most toxic and

one though is toxic and and
also for the P.V.P. this effect and

we use they have preference to attach to
well one more one more than one on one.

So as a result of that you know the school
kind of surface facet really plays

an important role.

For the toxicity measurements here.

And also for the sewers as we said that
you know always make nanomaterials and

you keep the increased illusion.

There is an aging problem there.

Over the age of means that.

Perhaps you see a very nice car at all.

You say all freshly made and as time goes
on you find that OK starts to orange.

That's an indication that catch those kind
of process monic property changes because

of the change in the fog.

And so we feel we did experiments
means two months old fresh

means that a fresh pot of coffee and two
months old coffee and we found that yeah.

It's consistent six in the enemy took
ages aged they always intend to be more

POCs it OK if we look at the details and
ageing means that most of time means that

it starts to lose the shop corners and
there is a process to release to audience.

OK So first of all they start to
lose those kind of the mythology and

they release you and so what we did is
we again we measure the concentration of

the release of Super ions then we did
this toxicity measurements at this kind

of concentration range and we found
that this is not due to the release

of the sewer ions coming out from
the nanomaterials So then we go back and.

And look at the facet.

So you can see that you know those
kind of the party host it's get

you know when you start to
lose corners you actually in.

For nanoparticles it has majority
of one one one surface again.

So this is consistent to
the fact that argument is that

when the size of particles from
the cube changes to fears.

You know its star is gradually
introduce more one on one facet and

eventually you have the different facets
from conversion from Won't one the old one

that is why you know this
is more toxic of this.

And again we have the cell internalization
N. and what we have done is you

have a part all of those kind of Sooner
particles incubated with the East so

that you can wash out the particles
that you have you know before and

after concentration solutions.

Then you do the measurement of I.C.B.M.'s
and we found that yeah seventy.

Sorry seventy percent of particles
should get into the cell.

And where the where do they go.

So at least you know it's just the based
on those kind of the mass and.

I wish we could share the same
excitement from the team and

the person has shown and
these you can see that.

Yeah.
We only see a little bit of silver gets

into the cells and we couldn't see.

I mean seventy percent that's a majority
of silver should get into the cell but

we can identify many of them.

OK and either did show a little
bit of stew or cumulated there but

it's not convincing that cup a possibility
is there what it is that perhaps

the particles gets into the cell and
in the condition they start to dissolve.

The other possibility is that because we
have done a careful eye characterize Asian

and culture media but we have never
taken a serious consideration

about what really happened to a particle
aggregation is in the cellar environment.

So if they dissolve the create
super ions they kill the cell.

If the aggregates they perhaps they
they were hiding in one playing.

We just couldn't see it.

So this is still.

And ongoing research and actually this
will provide some motivations for

me to just continue some
investigations as I was discussed.

Next.
So

in conclusion we actually you know use
the east the cell as the system and

use sewer nanostructures and
the control of their size shape and

service charge to try it was an attempt
to understand toxicity issue of course.

And so we concluded that size shape and
surface chemistry really play an important

role and this is a big question here is
what really happened to the particles

when they get into the cell and this is a
kind of like unfinished and that will shed

light on the future directions we want
to explore and specifically on I want

to own my own my future research because
I just started Georgia Tech in January.

So I'm allying my
research on the areas and

specifically we want to continue to use
the sewer nano materials as the building

blocks because I'm very interested in
class monic properties of silver and

use it for the imaging and
sensing application to perform.

And again you know in order to national
platform means that you know you

start it was raw materials you really want
to build those kind of functional groups

attached to the beauty blogs.

And the major question is what's the fate.

Now and to really interact
with those kind of cells and

all those and internalization of the
particles and specifically I think that

we need to really study very hard
to understand this release process

of the Silver to silver ions if you
really can control them biocompatible.

If you don't control them.

Yeah you can use it as and
you microbial agent.

And I think that you know as we
discussed previously that involves

was lots of steps and
the one Materials one biological systems.

Then if you think about ten materials and

ten biological systems there there hundred
possibilities are even more so when

we think that perhaps we should really
start to think about have form that can

do a high screen throughput to see what's
the nature of these particles and spectra.

So what we want to do is formally droplets
OK So we wanted to formally droplets and

it's kind of like the water
droplets in the oil suspension.

So these droplets and we want to use these
droplets to make their particles into

opulence OK so there and we also want to
you know if you can imagine that you can

feeding soon and particles in the feeding
different ingredients in those into these

channels to really use droplets as
a nano beakers to see what really

is going on with in terms of
aggregation release of sewer ions and

interaction with cells and
specifically I'm developing this optical

detection systems detection systems for
like some focal and

some folk around to really monitor those
kind of in situ measurements there and

you know this is a brew print
that involves lots of effort and

this is starting point and I think that
you know I'm right I'm the only one and

graduation just start it lab is
you body and the renovation.

But we did we are able to formulate
those kind of to food color droplets

all of oil or it's not so difficult.

We still can do this.

I look for the interaction with the
community and start my research project.

And specifically I want to send our
knowledge went to a national medal

technology national technology
infrastructure network supported by N.S.F.

and majority of the work has been.

Performed at Washington University in
St Louis where I spent four years there as

you can see that you know before the move
to watch you and I spent ten years there

and there is a straight line from here and
there and if you look at them.

If you give you think about
the map is the Nano subject and

I think the fusion really plays
the role here and I'm out here.

So I think that I really look forward to
really working with the community here at

Georgia Tech and by all means with
the community to really understand

this important areas for
developing a safe on all technology paths.

Full commercialisation
thank you very much.

Whether these soon and porticos across.

I don't know.

You know.

Yeah.
Actually we will do all that you tell us

so that's why we want to set up
the because I'm a I'm a chemist and

a physical chemist.

Then I know all those kind of
physical characterization message and

I mean the material science right now.

So we try to do a good job for

understanding all to the surface
modification and characterization then we.

I need collaborators to really work on.

And the stand those can our processes
are steps we can continue for

the understanding of that and if you ask
me how these particles gets into the cell

and I read a book and
I just couldn't figure it out.

I only could figure that OK.

The sooner I was well be able to getting
because it's I am very small but

apparently it does even for the pencil.

So we could leave the roots we
found that the ions is there so

it does penetrate into those kind of
thick walls and get into the cell.

But it is true.

Yes yes.

All of them.

You know or

yeah I think that you know these two
questions are the challenges opportunities

we're going to do more.

So in regards to the first
question how you really quantify

the capping agents on
the sewer structures.

I think that we're developing this
sourcing hence Rama scattering.

OK so what the what it does
is pretty much like for

you in an excuse because
they have shot corners.

They intend to you know when you shoot
a light out it is intent to have to you.

Hence the electromagnetic field.

So as such when you have those kind
of tapping agents in proximity to

the surface you will be able to see
from the Raman Singh of this cap.

So you can use this Raman spectroscopy
to monitor the absorption

process of this cutting edge
in all the washing process.

That can be done but as I said in the U.V.

if you ask me what really happened for
P.V.P. all those have happy aging to put

on the surface is just like you have
a hair of mine coating on my head.

So it's really hard to quantify them.

And act and
the second question is that yeah.

How could you really you know you
look at different size and shape and

how could you really normalize to the
findings all you know normalize everything

to compare with those kind of results and
I think at this point you know it's

just like you know you raise the question
is whether you look at the particle size

number of particles or you look at
mess right now we're looking at mass.

So like twenty nanometer
versus sixty nine meters.

If they have the same mass they
have different number of particles

you're comparing West.

And I don't know how to.

Handle those kind of things and perhaps
it's like in the research community

previously people always use solution
base to do the toxicity evaluation.

So concentration is accurate but
when we get into this narrow routine.

It might be different.

So we just need to really understand
what's going on where they

have to do different experiments to
really to find a better approach

to addressing those kind
of challenging questions

that can shed light on the future
understanding of this toxicity issue.

Not yet not yet yet but these are our
Those kind of things on the list but

it's kind of like this is the preliminary
data but that can serve as a guy lines to

really explore what's really going on with
their Yeah but you raise a good question.

Good good point and

because if you really can't cap those kind
of the sewers with benign molecules or

Legan's perhaps they are not toxic they
don't release the super ion either.

So also you can grow a layer
of oxide on the sewer.

I think layer.

Perhaps and can really encapsulates those
kind of sewer ions inside of cubes.

Yes.

All this is strictly rely on
the observation and that's.

OK So I think that you know.

You know if you look at a you
know the one was the Adams

made a different arrangement of this and
intends to become more reactive.

So you have more two atoms
exposed to the surface.

They're all to Malaysia can become
more toxic versus one all surface.

That because you do have
the different arrangement of the.

The packing is different for
one on one and one all surface.

Of the world.

So far we found that because it depends on
the concentration of particles you use and

I think.

A degree of P.V.
is always there because after distances.

You can always have a thing layout P.V.P.
N.P.P.

is a greats of ACTON So that actually you
know it helps not to just formulate and

aggregation and
this kind of concentration.

We did an observation and
the aggregation issues for

the evaluation at least twenty four hours.

P.V.P. actually called to of it for
the place we didn't see aggregation either

P.V.P. is selectively coded
out they prefer to code and

won't work well or surface on the cubes.