Biomedical Engineering Reference
In-Depth Information
TABLe 14.7
An.Example.of.Electrospinning.in.Enzyme.Engineering
a
Type of
Electrospinning
Fiber
Diameter
Goal
Polymer
Enzyme
Results
To.immobilize.the.
model.enzyme,.
α-chymotrypsin,.
and.examine.its.
catalytic.
behaviors
Polystyrene
(PS)
Randomly.
aligned
120.nm-1.μm
α-Chymotrypsin
Attachment.
achieved.by.
submerging.the.
ibers.into.an.
aqueous.buffer.
containing.the.
enzyme
Hydrolytic.
activity.of.the.
nanoibrous.
enzyme.in.
aqueous.
solutions.was.
over.65%.of.the.
native.enzyme
Covalent.
binding.of.the.
enzyme.to.the.
nanoibers.led.
to.an.18-fold.
longer.half-life.
in.methanol
a.
Case.Study:.Jia.et.al..(2002).
14.4.3 electrospun Nanofibers in enzyme engineering
Electrospinning.has.recently.gained.attention.in.the.immobilization.and.controlled.release.
of.enzymes..A.representative.case.study.has.been.presented.in.Table.14.7..Immobilization.
of.enzymes.is.essential.because.this.action.stabilizes.and.enhances.enzyme.performance.
(Wan.et.al..2008,.Tran.et.al..2011)..Electrospinning.is.a.popular.technique.in.this.area.because.
the.immense.surface.area.of.the.ibers.and.the.freestanding.structures.that.can.be.formed.
upon. collection. allow. for. easy. handling. (Sundarrajan. et. al.. 2010,. Moreno. et. al.. 2011).. By.
taking.advantage.of.core-shell.electrospinning,.discussed.in.Section.14.2.5,.enzyme.nan-
oibers.have.been.fabricated..This.is.advantageous.to.the.ield.of.nanobiotechnology.again.
because. membranes. of. nanoibrous. enzymes. present. a. high. surface. area. and. a. simple.
separation.of.biocatalyst.and.substrate.(Tran.et.al..2011)..Two.speciic.examples.of.how.this.
is.vital.to.the.ield.of.nanobiotechnology.involve.the.enzymes.cellulase.and.laccase.
Cellulases.are.a.series.of.enzymes.that.assemble.to.catalyze.the.hydrolysis.of.cellulose.
to.glucose.(Singhania.et.al..2010)..This.is.critical.for.alternative.fuel.research.because.cel-
lulose.is.a.hopeful.source.for.renewable.energy.(Li.et.al..2007,.Tran.et.al..2011)..However,.in.
order.to.be.used.as.a.biofuel,.it.must.be.converted.from.a.biomass.via.catalytic.processes.
(Sukumaran.et.al..2009)..This.is.where.cellulase.comes.in.and.facilitates.the.operation..Tran.
et.al..used.core-shell.electrospinning.to.create.PEO-cellulase.ibers,.crosslinked.the.cellu-
lase.core.and.tested.the.activity.of.the.enzyme.on.an.insoluble.paper.substrate..Although.
their. results. were. preliminary,. they. found. that. the. activity. of. the. crosslinked. enzyme.
within.the.nanoibers.was.similar.to.other.crosslinked.cellulases.
Laccase. is. a. copper-containing. oxidase. that. is. capable. of. catalyzing. one-electron.
oxidation.of.various.compounds.(Lettera.et.al..2010)..These.compounds.include.phenols,.
chlorinated. phenols,. aromatic. substrates,. pesticides,. endocrine. disrupters,. and. various.
dyes,.to.name.a.few.(Dai.et.al..2010,.Majeau.et.al..2010)..One.important.application.of.laccase.
is.biodegradation.and.biotransformation.of.pollutants,.such.as.for.wastewater.treatment.
(Auriol.et.al..2008,.Garcia.et.al..2011)..The.issue.with.using.this.enzyme.in.free.form.is.that.
it.loses.its.activity.quickly.in.aqueous.solutions.(Shin-ya.et.al..2005)..Thus,.there.is.a.need.
for.immobilizing.laccase.in.order.to.increase.its.stability..Core-shell.electrospinning.has.
