Biomedical Engineering Reference
In-Depth Information
a
b
C
s
= C
0
e
-t/t
τ = V
s
h
gel
/D
avg
A
c
Add soluble
factor C = C
0
Time to steady state: t
SS
= L
2
/2D
Dosing window
C
S
< C
0
Agarose
Source
h
gel
C
S
PDMS
Sink
3-D gel matrix
Dosing window
Dosing window
3-D gel matrix
Source
Sink
1 mm
L
250 µm
Linear opposing
Exponential opposing
Replenish
source: C = C
S
Replace sink
volume: C = 0
FIGURE 3.89
Agarose-illed.microchannels.as.gradient.generators..(From.V..Abhyankar,.Michael.W..
Toepke,.Christa.L..Cortesio,.Mary.A..Lokuta,.Anna.Huttenlocher,.and.David.J..Beebe,.“A.platform.
for.assessing.chemotactic.migration.within.a.spatiotemporally.deined.3D.microenvironment,”.
Lab
Chip
.8,.1507-1515,.2008..Reproduced.with.permission.from.The.Royal.Society.of.Chemistry.)
Gradient
a
b
Inlet
Collagen
Inlet
200 µm
Growth factor
Media
PDMS
1 mm
Outlet
Gradient
across
bridge channel
Main channel
c
d
1.0
e
0.5
Sink
Source
Sink
Source
200 µm
0.0
0.0 0.2 0.4 0.6 0.8 1.0
1.0
f
0.5
0.0
1.0
0.0 0.2 0.4 0.6 0.8 1.0
g
Gradient
region
Gradient
region
0.5
0.0
0.0 0.2 0.4 0.6 0.8 1.0
Normalized position
Inject gel A
Polymerize
Inject gel B
Polymerize
h
FIGURE 3.90
ECM.gel-illed.microchannels.as.gradient.generators..(From.Bobak.Mosadegh,.Carlos.
Huang,.Jeong.Won.Park,.Hwa.Sung.Shin,.Bong.Geun.Chung,.Sun-Kyu.Hwang,.Kun-Hong.Lee,.Hyung.
Joon. Kim,. James. Brody,. and. Noo. Li. Jeon,. “Generation. of. stable. complex. gradients. across. two-.
dimensional.surfaces.and.three-dimensional.gels,”.
Langmuir
.23,.10910-10912,.2007..Reproduced.
with.permission.from.the.American.Chemical.Society..Figure.contributed.by.Noo.Li.Jeon.)
