Dr.
Todd
Hoare
Associate
Professor
and
University
Scholar,
Department
of
Chemical
Engineering, McMaster
University
Canada
Research
Chair
in
Engineered
Smart
Materials
(Tier
2)
Abstract:
Hydrogels
have
been
widely
used
in
a
variety
of
biomedical
and
biosensing
applications
due
to
their
favourable
mechanical
properties
(mimicking
those
of
soft
tissues in
vivo while
facilitating
high
sensor
flexibility),
typically
low
non-specific
protein
adsorption
(minimizing
inflammation in
vivo and
reducing
sensor
interference),
and
capacity
for
controlling
diffusion
(enabling
prolonged
drug
release in
vivo and
non-covalent
biomolecule
immobilization
on
biosensors).
However,
the
elasticity
of
conventional
pre-formed
hydrogels
limits
their
capacity
to
be
delivered
via
injection in
vivo or
printed
in
2D
or
3D
geometries
to
develop
functional
sensor
coatings
or
structured
biomaterials.
In
this
context, in
situ-gelling
hydrogels
that
can
spontaneously
gel
following
mixing
of
functionalized
precursor
polymers
can
substantially
expand
the
scope
of
potential
hydrogel
applications.
In
this
presentation,
I
will
discuss
recent
work
from
my
laboratory
focused
on
designing
and
exploiting
the
properties
of
hydrazone
crosslinked
poly
(oligoethylene
glycol
methacrylate)
(POEGMA)
hydrogels
formed
by
simple
mixing
of
hydrazide
and
aldehyde-functionalized
POEGMA
oligomers.
The
hydrazone
crosslinking
chemistry
is
kinetically
independent
from
body
chemistry
and
enables
fast
(as
low
as
<1
s)
gelation
times,
amenable
to
printing
applications.
In
tissue
engineering,
these
properties
allow
for
the
direct
fabrication
of
cell-loaded
nanofibrous
scaffolds
supporting
cell
propagation
even
after
freezing
and/or
the
alignment
cell
growth
and
differentiation
along
a
defined
axis.
In
biosensor
applications,
such
hydrogels
can
be
self-assembled
or
ink
jet
printed
on
cellulose-based
supports
to
create
high-resolution
paper-based
lateral
flow
bioassays
for
antigen
detection
and
printed
multiwell
bioassay
plates
for
high-throughput
drug
screening.
Biosketch:
Todd
Hoare
received
a
B.Sc.
(Eng.)
in
Engineering
Chemistry
from
Queen’s
University
in
2001
and
a
Ph.D.
in
Chemical
Engineering
from
McMaster
in
2006.
Dr.
Hoare’s
work
has
been
profiled
by
Popular
Science,
Maclean’s,
and
BBC
for
its
potential
in
solving
clinical
challenges
through
innovative
smart
materials
design. He
has won
an NSERC
Innovation
Challenge
award recognizing
the
novelty
of
his
research.
[Full
Bio]