Biomedical Engineering Reference
In-Depth Information
In. this. section,. multiple. ield. researchers. attribute. speciic. works. aided. by. nano/micro-
technologies.. The. major. part. of. work. in. tissue. engineering. involves. nanotechnological.
strategies.for.engineering.complex.tissues.
Extracellular.microenvironment.reconstruction.is.critical.for.cell.growth.and.the.integ-
rity.of.whole.tissue..For.mimicking. natural.organ.structure,.3D.scaffolding. with.micro-
sized. cells. are. cocultured. together. in. the. presence. of. chemical,. physical,. and. biological.
cues.. The. long-term. goal. of. tissue. engineering. is. to. achieve. a. speciic. function,. assisted.
by.nano/microtechnologies..The.size.of.most.ECM.components.ranges.from.10.to.several.
hundreds.of.nanometers,.and.several.techniques.can.be.used.to.facilitate.cell-ECM.micro-
environment.recreation.
Electrospinning.is.a.common.technique.used.to.generate.nanoibers.with.natural.or.syn-
thetic.materials..The.diameter.of.nanoibers.using.the.electospinning.technique.is.around.
50-500.nm.in.range..Another.technique.named.molecular.self-assembly.is.a.nanofabrica-
tion.approach.with.the.characteristic.of.the.spontaneous.organization.of.individual.com-
ponents.into.an.ordered.structure.with.noncovalent.bonds..Due.to.the.peptide.amphiphile.
application,.the.iber.diameter.can.reach.10.nm.and.the.pore.size.of.the.scaffold.is.around.
5-200.nm..The.main.properties.of.nanoibers.include.high.porosity.and.high.spatial.inter-
connectivity,. which. provide. friendly. scaffolds. for. cells. or. other. molecular. loading.. The.
orientation.of.nanoibers.presents.obvious.guidance.for.neural.cells,.cardiac.cells,.or.other.
skeletal.sensitivity.cells..The.nanoscale.topographies.created.by.nanoibers.with.random.
order. and. a. parallel. manner. induce. multiple. cell. growth,. migration,. and. differentiation.
properties..For.investigating.tumor.cell.motility.in.vitro.with.its.native.behavior,.biocom-
patible. scaffolds. are. formed.by. electrospinning. submicron-sized. ibers. (Agudelo-Garcia.
et. al.. 2011).. This. presents. a. deformable. substrate. containing. topography;. the. molecular.
mechanisms. of. cell. migration. were. investigated.. The. experiment. indicated. that. glioma.
cell.migration.was.reduced.by.STAT3.inhibitors.at.subtoxic.concentrations.and.revealed.
one.of.the.cell.migration.mechanisms.in.vitro.by.this.micro/nanotechnique.
Nanopatterning. technology. as. an. effective. tool. can. create. nanoscale. structure. even.
using.bimolecular.or.biomaterials.on.different.substrates,.which.may.regulate.cellular.and.
genomic. level. behaviors. and. function.change.. Cells. can. respond. to. surrounding. micro-
environments.by.contact.guidance.with.topographical.feature.presence,.which.inluence.
cellular. morphologies. and. behaviors.. Nanopatterning. techniques. create. a. structure. or.
length.scale.from.a.few.nanometers.to.a.micrometer.scale.for.mimicking.the.native.ECM.
that.surrounds.cells..Various.geometries,.including.nanogrooves,.nanopillars,.or.nanow-
ells,.were.demonstrated.and.investigated.for.integrative.biology.by.different.groups..The.
typical.example.of.nanopatterning.topographic.substrates'.guidance.of.cell.performance.
is.the.induction.of.epithelial.cells'.elongation.and.alignment.along.grooves.and.ridges.in.
a.pattern.with.70.nm.dimensions.(Teixeira.et.al..2003)..Another.case.of.pattern.topography.
in. cell. shape. and. migration. is. based. on. the. integration. of. electrospun. iber. pattern. for.
cell.guidance.with.microluidic.channel.coninement..Both.patterned.surfaces.and.spatial.
factors.were.found.to.contribute.to.the.complex.cell.orientation.under.the.combined.dual.
effects. (Zhang. et. al.. 2011a;. Figure. 21.3).. Besides. nanopatterns,. micropatterns. play. a. piv-
otal.role.in.guiding.cell.behavior.and.differentiation..Many.works.are.focusing.on.neuron.
development. with. surface. patterning. stimulation.. Wissner-Gross. presented. the. poly-D-
lysine. (PDL). microlines. from. femtosecond. laser. beams. on. a. poly(ethylene. glycol). (PEG).
monolayer. surface.. Then,. high. content. screening. was. performed. for. elucidating. neuri-
tis. dynamics. (Wissner-Gross. et. al.. 2011).. Many. other. researchers. demonstrated. neuron.
growth.and.development.with.the.microfabrication.technique..Withers.et.al..showed.that.
the.poly-D-lysine.substrate.geometry.of.circular.nodes.or.crossed.line.plays.a.role.in.axon.
