Biomedical Engineering Reference
In-Depth Information
8.3 Influence of Size of Topographical Features
Topographical. features. at. both. the. microscale. and. the. nanoscale. have. been. shown. to.
inluence. a. multitude. of. cell. phenotypes,. ranging. from. attachment. to. proliferation. and.
to.differentiation.(Figure.8.4)..In.many.cases,.the.topography-mediated.cellular.response.
is. size. dependent,. and. often. complicated.. For. instance,. the. attachment,. migration,. and.
differentiation. of. hMSC. on. a. TiO
2
. nanotube-grafted. surface. are. dependent. on. the.
diameter.of.the.nanotubes.(Figure.8.5a;.Oh.et.al..2009)..The.literature.collectively.suggests.
that. nanotopography. is. a. more. potent. modulator. than. microtopography. in. affecting.
cell. behavior.. A. caveat. to. this. generalization. is. cell-type. dependency.. For. instance,.
macrophages. show. higher. propensity. of. phagocytosis. toward. microparticles. around.
1-2.μm.over.nanoparticles..It.is.possible,.then,.that.the.macrophages.might.respond.more.
strongly.to.microtopography.than.nanotopography,.as.suggested.in.a.study.characterizing.
the.response.of.murine.macrophages.to.PDMS.gratings.(Figure.8.5b;.Chen.et.al..2010).
8.3.1 Pillars
A. number. of. works. focus. on. the. changes. in. cell. behavior. that. arise. from. adjusting.
nanopillar.height..Milner.et.al..created.pillars.(400.or.700.nm.height).on.poly(l-lactic.acid).
(PLLA). and. subsequently. seeded. them. with. human. foreskin. ibroblasts.. Cell. adhesion.
increased.as.features.were.downsized,.but.the.converse.held.true.when.considering.cell.
Microscale
Morphogenesis
Migration
Proliferation
Adhesion
Nanoscale
Differentiation
Figure 8.4
(See companion CD for color igure.)
.Inluence.of.topography.on.cells..The.native.ECM.has.been.implicated.as.
a.key.player.in.guiding.various.cell-cell.and.cell-matrix.responses..Better.representations.of.these.events.and.
the.mechanisms.involved.can.be.elucidated.by.accounting.for.detail.at.the.nanoscale.level.
