Biomedical Engineering Reference
In-Depth Information
Exchange with
Ag+ (aqueous)
Reduction with
Citrate
Hydrogel
Silver nanoparticle
FIGURE 18.3
Formation.of.silver.nanoparticles.within.the.swollen.copolymeric.network..(Reproduced.with.permission.from.
Thomas,.V.,.et.al.,.
J. Colloid
.
Interface Sci.
,.315,.389,.2007..Copyright.Elsevier.)
18.2.2 Titanium Dioxide or Titania (TiO
2
) Nanoparticles
TiO
2
.exhibits.a.strong.antibacterial.activity.against.
E. coli
.when.exposed.to.near-UV.light.(with.
wavelengths.of.less.than.385.nm).
17
.It.has.also.been.shown.that.the.TiO
2
.photocatalytic.reaction.
results.in.continued.antibacterial.activity.after.the.UV.illumination.terminates..In.a.report.by.Li.
and.co-workers
18
.on.the.antimicrobial.effect.of.surgical.masks.coated.with.nanoparticles.con-
sisting.of.a.mixture.of.silver.nitrate.and.titanium.dioxide,.antimicrobial.activity.of.the.masks.
was.quantiied.according.to.the.procedure.of.AATCC.100-1999..The.resulting.100%.reduction.
in.viable.
E. coli
.and.
S. aureus
was.observed.in.the.coated.mask.after.48.h.of.incubation..Rana.
and.co-workers
19
.reported.on.the.antimicrobial.function.of.Nd
3+
-doped.anatase.titania-coated.
nickel.ferrite.composite.material,.using.
E. coli
.as.a.microbial..It.turns.out.that.doping.the.titania.
shell.with.neodymium.signiicantly.enhanced.the.photocatalytic.and.antimicrobial.function.
of.the.core-shell.composite.nanoparticles.without.inluencing.the.magnetic.characteristics.of.
the.nickel.ferrite.core..The.increased.performance.was.related.to.the.inhibition.of.electron-hole.
recombination.and.a.decrease.in.the.band.gap.energy.of.titania.
