1. Microfluidic
Synthesis
of
Lipid
Polymer
Hybrid
Nanopar;cles
for
Targeted
Drug
Delivery
Eri
Takami,
Folarin
Erogbogbo
Biomedical,
Chemical
and
Materials
Engineering
Department
San
Jose
State
University,
San
Jose,
CA
95112
USA
ABSTRACT
In
recent
years,
lipid-­‐polymer
hybrid
nanopar5cles
have
gained
a8en5on
as
an
efficient
drug
delivery
device
to
treat
various
diseases,
including
cardiovascular
disease,
tuberculosis,
and
cancer.
Nanoprecipita5on
and
self
assembly
of
lipid
polymer
par5cles
is
a
common
method
to
synthesize
drug
encapsulated
nanopar5cles
in
a
low
cost
manner.
However,
the
mul5-­‐
step
process
of
this
synthesis
method
causes
difficulty
in
consistently
producing
uniformly
sized
nanopar5cles.
Here
we
developed
a
microfluidic
device
that
u5lizes
a
three
channel
pathway
and
mixer
channel
to
produce
uniformly
sized
lipid
polymer
nanopar5cles
in
a
controlled
manner.
The
microfluidics
device
can
be
customized
to
synthesize
nanopar5cles
of
different
size,
different
encapsulated
drug,
and
different
surface
func5onaliza5on.
The
produc5on
of
higher
quality
nanopar5cles
in
an
efficient
manner
using
our
microfluidics
device
can
expedite
the
research
and
development
process
of
drug
delivering
lipid
polymer
nanopar5cles.
INTRODUCTION
What
are
Lipid
Polymer
Hybrid
Nanopar5cles?
• Lipid
Polymer
Hybrid
Nanopar5cles
(LPHN)
are
drug
delivery
vesicles
that
consists
of
a
polymer
core
and
a
lipid/lipid-­‐PEG
shell.
• The
polymer
core
allows
slow
elu5on
of
drug
• The
lipid/lipid-­‐PEG
shell
allows
the
nanopar5cle
to
evade
the
immune
system.
• The
PEG
extension
can
be
func5onalized
to
allow
targeted
drug
delivery
Benefits
• Low
drug
toxicity
• High
drug
reten5on
rate
• Targeted
drug
delivery
• Biocompa5ble
REFERENCES
1. Y.
Kim,
B.
Chung,
M.
Ma,
W.
Mulder,
Z.
Fayad,
O.
Farokhzad,
R.
and
Langer,
“Mass
produc+on
and
size
control
of
lipid-­‐
polymer
hybrid
nanopar+cles
through
controlled
microvor+ces,”
Nano
le8ers.
12,
3587–91
(2012).
2. L.
Zhang,
J.M.
Chan,
F.X.
Gu,
J.
Rhee,
A.
Wang,
A.
Radovic-­‐
Moreno,
F.
Alexis,
R.
Langer,
and
O.
Farokhzad,
“Self-­‐
assembled
lipid-­‐-­‐polymer
hybrid
nanopar+cles:
a
robust
drug
delivery
pla=orm,”
ACS
nano.
2,
1696–702
(2008).
LIPID
POLYMER
HYBRID
NANOPARTICLE
SYNTHESIS
• Conven5onal
method:
Nanoprecipita5on
method
•
Prepare
lipid/lipid-­‐PEG
solu5on
in
4%
ethanol
•
Heat
lipid
solu5on
to
65
to
allow
dispersion
of
lipid
par5cles
•
Dissolve
PLGA
in
acetonitrile
•
Add
PLGA
solvent
into
lipid
solu5on
dropwise
via
pipenng
•
Sonicate
solu5on
for
2
hours
to
allow
lipid
par5cles
form
shell
around
PLGA
par5cles
• Simple
and
robust;
requires
few
instruments
and
materials
• Main
drawbacks:
inefficiency
and
inconsistency
in
nanopar5cle
size
between
batches
•
Requires
4
hours
to
produce
5
mL
of
LPHN
•
Pipenng
and
sonica5on
is
not
consistent
each
5me
MICROFLUIDIC
SYNTHESIS
Microfluidic
Chip
Design
• Three
inlets
(top
for
polymer
solvent
and
sides
for
lipid
solu5on)
with
channels
at
200um
in
width.
• One
outlet
channel
at
3mm
width
for
solvent/solu5on
mixing.
• Height
of
the
channels
are
at
80
um.
Fabrica;on
Method
• Sop
Lithography;
silicone
wafer
mold
• PDMS
mold
on
glass
slide
via
plasma
bonding
• Syringe
needle
inlets
Nanopar;cle
Synthesis
• Flow
lipid/lipid-­‐PEG
solu5on
from
the
side
inlets
and
the
polymer
solvent
from
the
top
inlet
using
syringe
pumps.
• Adjust
flow
rate
of
solu5on
to
produce
desired
LPHN
par5cle
size.
• Collect
LPHN
par5cles
from
the
outlet
and
filter
out
solvent
using
tangen5al
flow
filtra5on.
Func5onalized
PEG
Lipid-­‐PEG
Lipid
PLGA
Drug
Receptor
Targe5ng
Lipid
Polymer
Hybrid
Nanopar5cle
Released
drug
Lipid/Lipid
PEG
solu;on
Polymer
solvent
Fig.
1:
Lipid
Polymer
Hybrid
Nanopar;cle
Fig.
2:
Targeted
Drug
Delivery
Fig.
3:
Nanoprecipita;on
Method
Fig.
4:
Silicone
wafer
Fig.
5:
PDMS
mold
Fig.
6:
Microfluidic
design
to
create
microvor;ces
[1]
MICROVORTICES
• According
to
research
by
Kim
et
al.,
Reynolds
number
above
30
produces
microvor5ces
in
the
middle
channel
of
the
microfluidic
device.
• Microvor5ces
allow
controlled
mixing
of
lipid
and
polymer
solu5on.
• Different
Reynolds
number
produces
different
nanopar5cle
diameter
size;
the
greater
the
Reynolds
number,
the
smaller
the
diameter.
RESULTS
• Flow
rate
of
polymer
solvent
was
kept
at
0.1
mL/min
while
lipid
solu5on
flow
rate
was
increased
incrementally:
0.1,
0.2,
1,
2,
3,
and
4
mL/min.
• At
1:10
polymer
to
lipid
flow
rate
ra5o
and
Reynold
number
of
22.73
and
below,
laminar
flow
can
be
seen
in
the
middle
channel.
• At
1:30
polymer
to
lipid
flow
rate
ra5o
and
Reynold
number
of
66.02,
microvor5ces
appeared
in
the
middle
channel.
A
B
C
D
E
F
Flow
Rate
(mL/min)
Reynolds
Number
A
0.3
3.25
B
0.5
5.41
C
2.1
22.73
D
4.1
44.37
E
6.1
66.02
F
8.1
87.66
Fig.
7:
Effect
of
Reynold
number
on
forma;on
of
microvor;ces
FUTURE
DIRECTIONS
• Using
DLS
and
TEM,
the
effects
of
Reynolds
number
on
the
nanopar5cle
size
will
be
measured
quanta5vely.
• Drug
encapsula5on/elu5on
rate
will
be
measured
using
LPHN
produced
through
microfluidic
synthesis.
• In
vitro
studies
will
be
conducted
on
bacteria
to
determine
LPHN
efficacy
in
inhibi5ng
bacterial
growth.