Biomedical Engineering Reference
In-Depth Information
Radially aligned
Random
(a)
(b)
1 mm
1 mm
(c)
500
μ
m
(d)
500
μ
m
Figure 9.6
Scaffolds of radially aligned
nanofibers for dura mater repair. (a,b) Fluo-
rescence micrographs showing the migration
of dura fibroblasts on scaffolds made of
(a) radially aligned nanofibers and (b) ran-
dom nanofibers, seven days post seeding of
the cells at the peripheries of the scaffolds.
Radial alignment induced almost complete
coverage of the scaffold by the cells, even
at the center while there was a large void
left in the center for the random nanofibers.
(c,d) Enlarged view of the center in (a) and
(b), respectively. A clear void can be seen
at the center for random nanofibers. Re-
produced with permission: from Ref. [68],
copyright 2010 American Chemical Society.
found that, when seeded on aligned PLLAfibers, hTSPCs oriented themselves along
the direction of the fibers and expressed higher level of tendon specific genes than
those seeded on randomfibers [18]. Figure 9.7a,b shows alkaline phosphatase (ALP)
stating of hTSPCs cultured on scaffolds consisting of aligned and random fibers,
respectively, in normal osteogenic induction media for two weeks. Figure 9.7c,d
shows alizarin red S staining of hTSPCs cultured on aligned and random scaffolds
under the same conditions. These results indicated the pluripotent nature of
the hTSPCs. Figure 9.7e,f shows Masson's trichrome staining of collagen fibers
formed on the fibrous scaffolds after six weeks
in vivo
. Whereas aligned fibers
induced the formation of aligned collagen fibrils similar to the native system,
random fibers resulted in the formation of haphazard collagen fibrils. Shin and
co-workers investigated the influence of nanofiber alignment and the direction
of mechanical strain stimulation on ECM production of human anterior cruciate
ligament (hACL) fibroblast [103]. The hACL fibroblasts on the aligned nanofibers
were spindle-shaped and oriented in the direction of the nanofibers. Significantly
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