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Hello, I am Dora Safar from
the School of Medicine
at the Royal College of
Surgeons in Ireland.
I am attached to the Soft
Matter Research Group
at the Royal College of
Surgeons in Ireland.
This is led by Dr. Roshan Deen.
The main focus of the
research group is to develop
new types of hydrogels for
biomedical applications.
My research interest is in
developing new types of
hydrogels for drug delivery
and tissue engineering
applications.
In this lecture, I
will be presenting
a review of polymeric
gels for drug delivery.
I will be presenting a
variety of polymeric gels
that are used for
controlled drug delivery
and I will highlight some
of the main examples.
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The outline of this lecture
will be the following.
We will start with
hydrogels and properties,
then we will move on to the
classification of hydrogels.
Then I will talk about the
swelling of hydrogels and
the types of water that are
present in swollen gels.
After this,
we will look at some major
drug delivery systems.
This will be followed by the medical
applications of a few hydrogels.
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By definition,
hydrogels are crosslinked
polymeric materials
that can absorb large
amounts of water
or any physiological fluids.
For any controlled drug
delivery application,
this swelling is the
fundamental property.
For a material to be
considered a hydrogel,
it should contain at
least 10% of water
by weight or by volume.
When the water content
is more than 95%,
the hydrogel is called a
superabsorbent hydrogel.
The most common example
of a superabsorbent
is baby diapers.
A thin layer of a hydrogel
is used in baby diapers
to absorb large
amounts of liquid.
The structural integrity
of the swollen hydrogel
is maintained by either
a physical crosslinking
or a chemical crosslinking.
The physical crosslinking
is non-permanent,
whereas the chemical
crosslinking is permanent.
The figure shown
illustrates that when you
take a dry hydrogel
and place it in water,
the hydrogel absorbs
the water and swells,
becoming rubbery in nature.
The blue spheres represent
the water molecules
within the swollen hydrogel.
