160
Bacterial Cellulose
interactive,.which.are.moist.and.efficiently.absorb.exudates;.and.(3).bioactive,.
which.are.also.moist.and.promote.wound.healing.by.decreasing.the.activity.
of.destructive.proteases.(e.g.,.collagen-based.dressings),.releasing.bioactive.
agents.like.antimicrobials,.antibiotics,.and.growth.factors.(Vasconcelos.and.
Cavaco-Paulo.2011)..These.bioactive.wound.dressings,.which.are.used.in.the.
cleansing.of.necrotic.tissues,.contain.immobilized.proteolytic.enzymes.like.
trypsin.or.collagenase.(Yudanova.and.Reshetov.2006)..They.may.also.carry.
antimicrobial.agents.
Passive.wound.coverings.require.frequent.changes.that.are.usually.painful.and.cause.scab.and.skin.stripping..Interactive.and.bioactive.dressings.are.
more.likely.to.prevent.dressing-related.pain.and.discomfort.in.patients.with.
exuding.wounds..They.are.fabricated.from.natural.polymers.(e.g.,.chitin.and.
chitosan,. alginate,. cellulose. and. its. derivatives,. keratin,. elastin,. fibrin,. silk.
fibroin,.collagen.or.its.denatured.form,.gelatin,.etc.).and.synthetics.(e.g.,.polyurethane,.polypropylene,.polytetrafluoroethylene.[PTFE].or.silicone-based).
(Davies.and.Rippon.2010;.Gupta.et.al..2010;.Vasconcelos.and.Cavaco-Paulo.
2011)..Recently.the.tendency.to.replace.synthetic.dressings.with.natural.ones.
or.to.use.their.blends.has.been.observed.
Carbohydrate.polymers.like.cellulose.are.frequently.used.in.the.form.of.
hydrogels,.which.have.a.three-dimensional.(3D).network.structure.and.can.
swell. in. aqueous. media. without. dissolution.. Plant. cellulose. hydrogels. are.
obtained.by.using.complex.and.environmentally.unfriendly.solvent.systems.
(Chang.and.Zhang.2011),.while.bacterial.nanocellulose.(BNC).hydrogels.are.
natural. products. derived. through. environmentally. friendly. stationary. or.
agitated.cultures.of.certain.bacteria,.among.which.Gluconacetobacter xylinus.
strains.are.considered.to.be.the.most.efficient.producers.(Bielecki.et.al..2002)..
BNC,.which.can.be.easily.subjected.to.patient-oriented.modifications,.is.an.
excellent.matrix.for.fabrication.of.interactive.and.bioactive.wound.dressings.
Properties of BNC Dressings
BNC.membranes.have.been.used.as.natural.polymeric.wound.care.materials.
since.the.1980s..They.have.been.shown.to.meet.the.majority.of.performance.
requirements. of. an. ideal. wound. dressing. and. to. substantially. accelerate. the. healing. process. in. various. types. of. wounds.. In-use. characteristics,.
patient-centered.outcomes.of.BNC.wound.dressings,.and.their.potential.utilization.methods.are.collected.in.Table 8.2..Sterile.BNC.membranes.completely.
deprived. of. microbial. cells,. their. fragments,. and. culture. medium. residues.
have. been. successfully. used. in. the. treatment. of. various. acute. and. chronic.
wounds.(Alvarez.et.al..2004;.Petersen.and.Gatenholm.2011;.Solway.et.al..2010)..
The. suitability. of. BNC. wound. dressings. for. the. treatment. of. hard-to-heal.
wounds.is.also.claimed.in.patents.and.patent.applications.(Table 8.3).