Tailor-Made and Biodegradable Vascular Scaffolds - Microsurgery: Advances, Simulations, and Applications - page 287

Coated
Silicon wafer
Acrylic
Steel

MSPs

10 m m 10 mm

Neodymium magnet

c) Patterning device
comprising acrylic and steel
wires (d= 0.9, 0.7, 0.45,
0.28 mm)

b) Patterning device
comprising acrylic and
thin steel sheets (t = 0.2
mm)

a) Schematic of patterned self-
assembly by use of patterned
magnetic field

0.25

Bz

0.2

0.2-0.25
0.15-0.2
0.1-0.15
0.05-0.1
0-0.05

0.15

0.1

50

0.05

40

5 00 Mm

30

1 m m

20

y

0

10 50

40

30

0 20

x

10

0

e) Linearly assembled MSPs
(250 < d < 300 mm)

f) Magnified image of
assembled MSPs

d) Magnetic flux density on the
surface of patterning device b)

0.4

Bz

0.3

0.3-0.4
0.2-0.3
0.1-0.2
0-0.1

0.2

0.1

25

20

15

y

10

25
0

5

20

15

0 10

x

5

0

h) Assembly of MSPs on a polka-dot
pattern

g) Magnetic flux density on the
surface of patterning device c)

Figure 8.23 Magnetic manipulation and patterning of MSPs by use of
external magnetic force and patterning device.

By using the linear assembly of MSPs 2 based on the schematic
of Fig. 8.23, polymer solution of PLCL was cast on those patterned
particles similarly described in Fig. 8.17. We call this combination
method of magnetic patterning and sugar leaching as “patterned
sugar leaching.” Figures 8.24(a, b) show a pore network running
to vertical direction from a macroscopic viewpoint. Although there
was variance of line width depending on sites, usage of the magnetic
patterning device could produce a patterned pore network with the
line width of several millimeters. By the combination of magnetic
porogens and a 2D patterned magnetic ield, the positioning of pores
( G

> 50 μ m) could be controlled two-dimensionally in the order of
millimeters.