Well this is actually for the minister.

During this investors who were
going to be involved until the fall

so it was a very successful first

class mysteries student speakers today.

I wonder if you can
serve our first week or

want to as a fourth year student
you know here in program.

Is home base.

It's real science and
engineering and he's coming our way

and I see his undergraduate degree.

You know like are trying to
engineer University logic.

Thank you for this.

Thank you very much.

Thank you and thank you for
the opportunity to be here today.

I'll give you a talk about the fabrication
of electrons paan titanium nano Phoebus

mesh and the about the mission of the OS
to blast differentiation potential and

this topic will have you know
material science component to it.

We do surface analysis of this bomb
materials that we use but it also is much

for me in toto is the application and the
fine obligation at the end is for bone.

You know substitute and basically we need
to know if these materials can actually

enhance bone formation and
bone formation it's a complex process and

I'll try to talk a little bit about it but
so I'll start with some motivation and

background and talk about the scaffold
properties that we're going to look at.

And then give you my hypothesis on
the objective for the study and then.

Share with you.

The methods the results and
some final conclusions.

So basically.

From two thousand and one to two thousand
and eleven it was to the bone and

joint decade because it was
recognized that bone and

joint injuries are the most reported
health condition in the United States and

it amounts to almost eight percent
of the United States G.D.P. And

even though bone and joint injuries
are not usually a direct cost of death.

I mean they definitely amount for a lot of
lost wages and chronic pains and a lot of.

You know problems for patients and
in the elderly population it

definitely does directly influence or
is related to the death of the patients.

And just some some numbers just to give
you an idea of how common they are and

specially for people that have bone
disease you know like last year process.

It's you know now known that
fifty percent of all women

over fifty years old will
suffer a bone fracture.

So it's really important to have tools or

ways to treat these patients that are in
a way a permanent and you know industry

that we're just showing you know what is
considered to be a nonunion and that's

when you suffer an injury that actually
cannot heal by itself and then there has

to be a surgical intervention to either
by putting a bone graft substitute or.

Or putting a fixation play
just to make it heal and

the green boxes just tell you are there.

Yes I have a commonly affected by bone and
joint decease.

So one of the most common
solutions to treat you know

bone injuries are implants right metallic
implants become very popular and

you know in specific cases
where they can be used.

They say.

So if a great purpose.

Unfortunately they are not
permanent implants you know we're

trying to make them permanent but that
the lifetime of most of these implants for

example hip replacement implants is
about ten to fifteen years old and so

that's sometimes not enough.

It used to be when you know the majority
of the patients getting the same plans

were older but now when you
know you probably have friends

that have already gotten titanium implants
either on their spine or on the legs and

you know ten to fifteen years is
nothing so we need to find ways of.

Providing these bone substitutes that
will be more permanent and that will take

advantage of the innate you know region
narrative capacities of the bone system.

So in that sense tissue
engineering is very promising

because it basically takes advantage
of the tools that the body and

nature has already given us and tissue
engineering is just basically trying to

mimic the national extracellular matrix or
them Vironment of the cells

to make them produce the factors
that they need to be happy.

Basically And what happens is that the
cells interact with the extra Matrix or

their environment now based Pacific
way and they have receptor seen their

membranes that can actually sense
different molecules by chemistry

by stiffness and so all of these
aspects can be taken advantage of when

we're designing biomaterials to
improve the outcome of a patient.

And at the end after these
receptors interact with them.

Vironment they actually start
signaling cascade that tell the so

which genes to transcribe and then
basically which proteins to produce and

with tissue engineering this
is what we're trying to do.

We're trying to mimic that
Environmental I mean that extra So

a matrix to promote specific responses.

The girl at the end is to
be able to regenerate bone.

Without using systemic drugs because in
that way we do it in a more natural way

and in a more sustainable way and
the most common substrate used for

tissue engineering are scaffolds there are
many different ways of doing scaffold some

of them include restrained salt
leaching and electricity and.

It isn't one that I
would talk about today.

Most of them have been use using
polymers and this is because well it's

easily accessible and they actually end
up having mechanical properties that

are closely related to the mechanical
properties of the extrasolar matrix.

Unfortunately Paula makes councils have
a poor about logical performance in

the sense that do not interact
directly with these polymers and

the proteins that interact with this
polymers also the ones needed for so

growth and so differentiation for
this reason in most

of the cases the groups end up having
to improves about logical performance

of this point examples by introducing
factors such as growth factors or

other chemical factors that will
improve the sub behavior but

another approach that other groups
have taken is actually using

bio active factors that gave structural
properties to the scaffold that enhance

the saw behavior such as including for
example ceramic particles such as

drugs the appetite which is one of the
main components of bone or titanium and

by including this by active factors you
can improve the behavior of the cells.

So my hypothesis in this
case is that close and

then a fever ceramic scaffolds can promote
also breast maturation and such so

behavior is regulated by structural
properties and the structural problems

that we talk about today will be the micro
roughness on the net of fiber diameter and

for that we basically designed Electra
spun mesh that is made out of titanium.

And where we could change the micro
roughness as well as the nine to five or

diameter and we tested it in vitro
with just sixty three cells to see

what was the last agenda potential.

And again no interest was to
create a scaffold that was

completely ceramic because it's
not been shown in the literature.

You know what is the effect of.

Membrane made out of to.

Taina titanium as that site has been shown
to have a very good biological performance

because it's actually the past of any
layer on top of all titanium implants.

So we know that you know it has
a good response in the body but

we don't know what would be the effect
of having actually pros and

then a few of us structure in that
differentiation of these cells so

what we used for
Spain is set up is basically.

The titanium I support POC site in
a solution that we could basically.

Use in the electricity and set up and

we had a collector a bronze pattern
collector that would allow us to basically

imprint this pattern on one of the size of
the scaffolds and this is the way that we

basically control if we had micro
roughness versus a flat side.

After the electricity process
these measures were actually

very flexible because they still had.

Their poly you know parole
they don't in it so

they had a poem a component in it but
then we consummated the samples at seven

hundred degree celcius to remove
all this poem or component and

at the end all that we had was a titanium
dioxide scaffold and I'll show

some of the characterization data to
prove what is the material that we have.

So first for the characterization we
wanted to know what was the micro

structure of the samples and we did that
by analyzing the samples on the microscope

and as you can see here we
have on the column on the left

the samples that were made
six percent P.V.P. and

on the column on the right we have some
things that were made ten percent P.V.P..

And on the top side we have

the side that we refer to as the flat
side which if we go back would

be the side that is six posed to
the syringe on the electricity and set up.

That's the side that is constantly
being replenished with new fibers and

it has no pattern to it.

It actually has a random
orientation a five or sonnet.

Rest is the side that is the pattern side
which was the one that was right in touch

with the bronze collector the one you can
see has a very well defined pattern of

cross-hatch And

when we did characterization of the
roughness we can clearly see that there's

a significant increase in roughness on the
pattern side compared to the flat side.

So some S.C.M.

studies to actually analyzed the five or
diameter and as you can see here.

You know the structure is very porous and
then a Febreze and

I deliver some magnifications with
the country station of the poor size and

we see that there is no big difference
between the processes of the six

percent on the ten percent P.V.P. titanium
dioxide scaffolds But when we move

to the higher magnification some we can
actually look at the fiber diameter

by an image analysis we can tell that the
fiber diameter of the six percent P.V.P.

is actually smaller than the fiber
them better of the ten percent P.V.P.

and the average damages were
around one hundred eighty and

three hundred forty nanometers.

It's also important to know the crystal
structure of these samples.

Because even though Actually
there's not that much information.

Confirming that the crystal structure
might have an effect on the Senate

of response.

It's too important to know
if we have the root or

structure of the anatase structure and
interestingly enough on these samples.

We have a combination of both so over here
we have the reference route out peaks from

the software and the anatase peaks
reference from the software and here we

have the X R D spectra for the six percent
scaffold and the ten percent scaffold.

And then spectra are very similar and
they both contain all peaks for

anatase and route tell.

It's also important to know what's
the chemistry on the samples because

that's definitely a parameter that
has been related to affect so

response and
on these samples we know that.

There are many compose of oxygen and
titanium in a ratio that you know

resembles the chemistry that we're working
with which is titanium dioxide and

we also find some traces of silicon and
calcium and

the silicon could be coming from when we
consummated samples we concentrate them

on top of a silicon wafer so that could
be some sort of contamination from that.

For the SO experiment.

It's very important to have still samples
when we're doing so experiments and

the samples of D.N.A. after class
a nation where a little bit brittle.

So instead of doing a lot of
play which is of a common.

To say shin method we use U.V.
surreally sation and

we've just sixty three cells which are
called my cell and they behave like pretty

osteoblasts meaning that they're also
a blast that if they're given the right.

Cues and the right properties they can
become a more mature osteoblasts or or

bone cell Auster Blass are the bone cells.

So for this reason the good model for
our studies and

we will have five groups which
are the plastic control and

then the four experimental groups which on
the flat side of the six percent P.V.P.

the pattern side of the six percent P.V.P.

the flat side of the ten percent on
the planet side of the ten percent purity.

And we basically grew them in to cause for
plates.

We first covered just
the surface of the scaffold

to allow the souce to actually
attach to the scaffold.

And then we replenish the well and
grew them for

twenty four hours after this twenty
four hours we move those samples

to a new play just to make sure that no
sauce attached to the bottom of the plate.

And then we grew them on twelve wall
plates on till there were confluent and

confluence it just means that one till
the SO scope of the entire surface.

When that happens is when we actually do
the this so assays which I'll show you.

In this life.

So first we looked at so
morphology and we basically

fixed the cells on top of the scaffold you
see in critical point drawing and we have

three different magnification as you can
see here on the left side we have so

it's growing on the flat side on the right
side we have souls growing on the patter

side and here we have six percent and
ten percent and the same on

the other side of the limb and if occasion
you can see that this growing pretty much

throughout the entire surface the respite
and what you would typically call.

Happy.

So morphology there won't spread and
they seem to be interacting well with

the surface when you get
a high magnification so

you can see that they actually are indeed
interacting with individual Gnana fibers.

But we don't see any clear differences
between comparing six percent

versus ten percent and

basically the same happens when we look
at the pattern sat where you know in some

cases we did see some kind of alignment
with some of the ridges in the pattern but

besides that we also see close interaction
between the cells on the fibers but

no significant differences between
the six percent of the ten percent.

Then we looked at the same number and this
is one of the assets that we do just to

know how much cells we
have on the surfaces and

how well they're growing it's related
to so proliferation and on the Y.

axis we have we just count the number
on the sample and on the bottom.

We have the different groups and
again it's just the plastic control and

then the flat side and
the patter side of the six percent and

the flat side on the platter
side of the ten percent.

And as you can see here.

Basically all experimental groups have
less cells than the plastic control.

Which in combination with
the data that I show you head.

It's a good resource and we actually
found that the lowest levels of

saw number were on the patter side of
the six percent and the ten percent.

Measureless.

Then we looked at some
differentiation markers so

it's important to know how much
the cells are police rating But

additionally it's also important to
know how these differentiating meaning.

How much the pain was the you know
becoming a I'm not sure osteoblasts and

to do that we have to markers we have an
imposter to specific activity which isn't

really differentiation marker
also brass differentiation and

also consing which is a late
differentiation marker of cost

to blast differentiation and
in our first at a specific activity.

We don't see many differences
between the groups except for

an increase on the flat side of
the six percent and actually decrease

on the pattern sides that when we compare
that to us are constant we actually see

an increase on the experimental
groups compare to the plastic and

the highest levels were found on
the pattern side of the ten percent.

And this actually is a very interesting
result because it correlates to many

many published studies in the literature
saying that also glass actually

more when they're growing on rough
surfaces and basically we're basically

corroborating those resource here where
we find that the most of friendship

it's also on the pattern side on the rough
side of the ten percent scaffolds.

We also looked at some local factors
that are being produced in the media and

these local factors basically
also pertaining relates to

an inhibitor of bone resorption there
are some songs that actually go and

eat bone as part of the normal
development of bone and

if you find any increase in Austria
protect grain that relates to

an increase in bone formation because
you're actually inhibiting the.

Us a bone resorption and what we see
here is that we found again the highest

levels on the pattern side of both the six
percent and the ten percent scaffolds and

then one with the top basket of
their growth factor which is and and

just any growth factor meaning that
it promotes blood vessel formation

one more time we see increased levels
on the pattern side of the scaffolds.

So in conclusion we were able to create
measure this that have that difference

surface roughness is at the macro level
and different than a fiber diameters

without changing the chemistry of the
crystal structure and in that way we can

actually isolate the effect of these
parameters of these properties on cell

response and we see that just by changing
the chemistry from plastic to the titanium

dioxide we can improve autographs
maturation and local Factor production.

But beyond that when we look
at that when we compare for

example microstructure and
then a fiber diameter.

We see that.

Separately facial is affected mainly by
the microstructure brought differentiation

and local Factor production are affected
by both the microstructure and

the Nano fiber down there and

basically having meshes that combine
micro a nano structure because in theory

having nanofibers is kind of an added
nano structure to the surface and

has the also blast maturation of
the local factory production and

at the end it's just important to have in
mind that even those every detail every

important factor of the of the surface
including surface structural

properties are important to be taken into
account when deciding about materials to

you know enhance bone formation and
with that I would like to think.

My laps and the funding sources and.

I'm open for any question.

I know it's probably kind of
a different talk and you get out.

Yes.

Yes.

Right.

That's that's a very good question and
in a way that's why with this experiment

at least we can call these substrates
scaffolds because they in reality they're

not the pros are not big enough for
these cells to go into the scaffold.

And there are some publications talking
about how the electricity in the method

usually creates samples that are in this
way you know that have small portion and

don't allow So in growth but actually
there are some techniques that are being

applied now to electricity where you
can actually create larger poor so

that the cells can actually
go inside this point.

Like you are right in this case are not
going inside but I think that we can still

take out from these data their effects of
those structural properties that could and

should be taken into consideration
even when doing scuffles that do

have larger pores.

It seems like there's a pattern here.

Just collectively it's certainly changing.

History.

Right.

Yeah I mean I think that it would
have an impact just by changing the.

You know the top ology of whatever.

Structure you give into the surface and
actually some studies have shown

on titanium substrates pure
titanium substrates that the closer

you mimic the natural
environment of bone happier.

Cells are and

this means that in the process of
bone formation and bone development.

You have both bone formation and also
bone resorption which is when the cells

come and actually eat away the bone
the has the micro cracks and

any small you know fissures or
injuries and when they do this they

have a rough surface because they asked if
I had the substrate and create these pits.

So they were able to show a group
actually was able to show that

the more you would mimic those pits
in terms of size in terms of you know

micro plus soup microstructure the better
the cells would behave so I think that

the pattern that we have there was what
we could get from our bronze collector.

If we could find other ways of
imprinting something that looked

more like natural Bone who probably
would get a better response.

Thank you.