Biomedical Engineering Reference
In-Depth Information
ilopodia.bent.around.the.nanocolumns,.highlighting.their.role.in.sensing.the.presented.
topographical.cues.(Dalby.et.al..2004c).
Arnold.et.al..generated.nanopatterns.on.glass.and.silicon.substrates.with.8.nm.gold.dots.
coated.with.c(RGDfK)-thiols.(cyclic.peptide.linked.via.the.spacer.aminohexanoic.acid.to.
mercaptopropione. acid),. which. were. subsequently. PEGylated.. The. dot. size. ensured. that.
solely.one.focal.adhesion.corresponded.to.each.individual.nanofeature..REF52-ibroblasts,.
MC3T3-ibroblasts,.and.B16-melanocytes.seeded.on.these.surfaces.all.pointed.to.a.maximal.
spacing.interval.between.58.and.73.nm..Above.the.latter.limit,.vinculin.cluster,.and.actin.iber.
formation.proved.disordered.(Arnold.et.al..2004)..In.a.later.study,.the.Spatz.group.prepared.
gold.nanodots.(8-12.nm.diameter).arranged.in.either.an.orderly.or.random.coniguration.
on. glass,. and. these. nanopatterns. were. functionalized. with. c(RGDfK)-thiol. ligand. (one.
per.nanodot)..To.ensure.high.speciicity.in.adhesion,.the.regions.without.nanodots.were.
PEG-passivated..MC3T3-E1.osteoblasts.cultured.on.the.various.glass.surfaces.differed.in.
morphological. traits. and. capacity. for. focal. adhesion.. Increasing. the. average. interligand.
spacing. caused. MC3T3-E1. osteoblasts. cultured. on. organized. nanopatterned. surfaces. to.
take.on.a.more.elongated.form,.along.with.fewer.cells.attaching.to.the.substrate..However,.
such.changes.did.not.manifest.on.disordered.nanopatterned.surfaces..But.more.importantly,.
the.authors.determined.that.successful.integrin.clustering.and.subsequent.focal.adhesion.
depended.on.interligand.spacing.of.70.nm.and.below.(Huang.et.al..2009).
Another. study. employed. CL. to. produce. patches. ranging. from. 200. to. 1000.nm. in. silicon.
wafers. using. gold. particles,. and. the. resulting. surfaces. were. then. enhanced. with. ibronec-
tin..Higher.mammalian.breast.cancer.cell.numbers.were.observed.on.larger.nanopatterns..
Notably,.focal.adhesion.complexes.became.more.pronounced.with.increasing.patch.size..Cells.
exhibited.less.rounded.morphology,.indicating.greater.interaction.with.the.surface..Despite.
no.production.of.mature.focal.adhesions,.these.indings.established.a.diameter.of.200.nm.as.
the.lower.limit.of.cell.adhesion.and.focal.complex.formation.(Malmström.et.al..2010).
8.2.2.3 Electron Beam Lithography
Electron.beam.lithography.(EBL).entails.bombarding.a.conductive.surface.with.electrons.
to.induce.alterations..This.method.requires.use.of.a.resist—a.derivative.of.a.high-molec-
ular-weight. polymer. solvent. solution—that. covers. the. substrate. and. retains. the. pattern.
to.be.imprinted.(Tseng.et.al..2003)..This.high-throughput.technique.caters.to.many.types.
of.materials.and.can.generate.a.versatile.array.of.nanopatterns.(Schmidt.and.Healy.2009)..
Resolution.below.10.nm.is.deemed.feasible.(Vieu.et.al..2000)..However,.limited.access.to.
appropriate.equipment,.time.consuming.nature.of.production,.and.prohibitive.costs.ham-
per.this.technology.from.becoming.commonplace.
Silicon.surfaces.consisting.of.120.nm.pits.arranged.in.a.hexagonal.fashion.were.compared.
with.lat.PMMA.surfaces.with.regards.to.ibroblast.adhesion..Results.demonstrated.larger.
cell. sizes,. better. cell. spreading,. and. proliferation. on. planar. substrates,. along. with. higher.
cytoskeletal. organization,. as. indicated. by. vimentin. and. actin. morphology.. Fibroblasts.
cultured. on. the. nanopatterned. surface. possessed. ilopodia. around. the. periphery. of. the.
nanopits,.implying.that.these.patterned.structures.impeded.focal.adhesion.(Dalby.et.al..2008).
EBL.also.enables.the.re-creation.of.structures.reminiscent.of.the.ibrous.ECM..Van.Delft.
et.al..crafted.sets.of.nanogrooves.varying.in.size.onto.polystyrene.material.with.the.aid.of.
silicon.wafer.templates..Under.a.ridge/groove.ratio.of.1:1,.both.depth.and.width.inluenced.
rat.dermal.ibroblast.alignment.(full.alignment.attained.with.parameters:.35.nm.depth.and.
200.nm. width);. narrow. grooves. purportedly. increased. random. cell. spreading,. with. the.
upper.limit.for.this.phenomenon.hovering.around.70-80.nm.(van.Delft.et.al..2008).
