Biomedical Engineering Reference
In-Depth Information
TABLe 20.3
Inluence.of.Nanoscale.Grooves.on.Cellular.Adhesion
Adhesion
Modulation
Study
Cell Type
Chemistry
Pitch
Depth/Height
Teixeira.et.al..
(2006)
Human.corneal.
epithelial.cells
Silicon.dioxide
400.and.
4000.nm
70.and.
1900.nm
Oblique.FA.
formation
Teixeira.et.al..
(2006)
Human.corneal.
epithelial.cells
Silicon.dioxide
800-2000.nm
550-1150.nm
Parallel.FA.
formation
Biggs.et.al..
(2008)
Human.
osteoblasts
Poly(methyl.
methacrylate)
10.μm
300.nm
Reduced.FA.
frequency
Karuri.et.al..
(2004)
Human.corneal.
epithelial.cells
Silicon.dioxide
400.nm
250.nm
FA.restricted.to.the.
tops.of.the.ridges
Heydarkhan-
Hagvall.et.al..
(2007)
Human.foreskin.
ibroblasts
Silicon.dioxide
230.nm
200-300.nm
Increased.integrin.
β 3 ,.FA.alignment
Lu.et.al..(2008)
Rat.aortic.
endothelial.cells
Titanium.
oxide
750.nm
150.nm
Increased.adhesion
Loesberg.et.al..
(2007)
Rat.dermal.
ibroblasts
Poly(styrene)
100.nm
35.nm
Reduced.alignment.
and.adhesion
Nanogroove.substrates.modulate.adhesion.orientation.as.well.as.regulating.adhesion.density..Studies.indicate.
that.the.cutoff.value.for.the.process.of.contact.guidance.is.100.nm.groove.width.and.34.nm.groove.depth.
elements,.which.have.been.reported.to.measure.∼20.to.30.nm.in.diameter.in.vasculature.
basement. membrane. (Liliensiek. et. al.. 2009),. and. ibril. bundles,. which. range. from. 15. to.
400.μm.in.diameter.in.tendon.tissue.(Kannus.2000)..Key.to.this.is.that.nanogroove.surfaces.
may.induce.enhanced.tissue.organization.and.facilitate.active.self-assembly.of.ECM.mol-
ecules.to.further.mediate.cell.attachment.and.orientation..Indeed,.the.elongated.morphol-
ogy.and.alignment.induced.by.grooved.substrates.may.resemble.the.natural.state.of.many.
cell.populations.in.vivo.and.is.observed.to.occur.in.a.wide.range.of.cell.types,.including.
ibroblasts.(Dalby.et.al..2003b),.osteoblasts.(Lenhert.et.al..2005),.neurons.(Yim.et.al..2007),.
and.MSCs.(Dalby.et.al..2006b),.which.respond.profoundly.to.grooved.substrates.and.have.
been. shown. to. upregulate. the. expression. of. components. of. the. ECM. (Chou. et. al.. 1995).
as. well. as. proteins. key. in. cellular. adhesion. (Dalby. et. al.. 2008b). and. the. transduction. of.
mechanical.forces.(Jin.et.al..2008).
As. with. the. topographies. discussed. earlier,. nanogroove. features. seem. to. inluence.
directly. the. formation. of. focal. adhesions. in. vitro,. by. simultaneously. providing. vertical.
ledges.that.disrupt.integrin.binding.as.well.as.topographically.planar.areas.that.facilitate.
integrin.binding..These.both.modulate.protein.adsorption.and.integrin.reinforcement.and.
furthermore. also. inluence. the. orientation. of. focal. adhesion. formation. (denBraber. et. al..
1998;.Teixeira.et.al..2004).
At. present,. no. clear. conclusions. have. been. reached. about. the. absolute. dimensions.
required.for.cellular.and.focal.adhesion.alignment;.most.likely.this.process.is.cell-speciic.
and.dependent.on.whether.the.cell.is.isolated.or.has.established.contact.with.adjacent.cells.
(Clark.et.al..1990)..It.is.probable.that.an.interplay.between.groove.pitch.and.groove.depth.
regulates.adhesion.alignment,.yet.present.studies.indicated.groove.depth.as.being.more.
inluential.in.this.process.(Clark.et.al..1990;.Loesberg.et.al..2007)..A.pivotal.study.by.Crouch.
et.al..investigated.anisotropic.cell.behavior.in.human.dermal.ibroblasts.with.respect.to.the.
aspect.ratio.(depth.to.width).of.gratings..Human.dermal.ibroblasts.were.found.to.increase.
their.alignment.and.elongation.with.increasing.aspect.ratios..While.aspect.ratios.as.small.
 
Search WWH ::




Custom Search