158
Bacterial Cellulose
healing,.speeds.up.restoration.of.the.wounded.tissue.to.its.normal.state,.
and. significantly. reduces. pain;. (3). it. is. highly. porous,. absorbable,. and.
capable.of.donating.moisture.while.simultaneously.absorbing.exudates;.
(4).it.conforms.to.any.shape.of.wound.and.is.very.light.and.transparent,.
but. forms. a. mechanically. durable. and. tight. physical. barrier. to. microbial. contamination. and. additional. injuries. while. providing. gaseous.
exchange;.(5).it.allows.easy.and.painless.removal.of.wound.coverings;.
(6).it.is.sterilizable,.nondegradable.in.mammalian.systems,.flexible,.elastic,.and.available.in.any.size.and.shape;.(7).it.can.be.infused.with.other.
therapeutic. substances. without. deterioration. of. its. inherent. features;.
(8). its. properties. can. be. tailored. to. individual. needs. through. deliberate. changes. in. culture. conditions. of. bacterial. producers,. their. genetic.
modifications,.or.postculture.treatments.of.the.polymer;.and.(9).it.forms.
homogeneous. blends. with. other. biocompatible. polymers. like. alginate,.
hyaluronic. acid,. or. soluble. cellulose. derivatives.. BNC. wound. dressings.have.been.successfully.used.in.the.treatment.of.acute.and.chronic.
wounds..BNC.has.also.been.applied.as.a.scaffold.material.in.skin.grafts.
and.as.a.protective.membrane.in.end-to-end.nerve.repair..Cosmetic.uses.
of.BNC.include.manufacturing.of.moisturizing.facial.masks.and.creams,.
peeling.agents,.fingernail.polish,.and.as.a.base.for.artificial.nails.
Performance Requirements of Wound Dressings
The.basic.function.of.wound.dressings.is.promotion.of.rapid.wound.healing.with.a.focus.not.only.on.functional,.but.also.cosmetic.results..Modern.
wound.dressings.are.designed.to.accelerate.the.major.outcome.of.treatment,.
which.is.a.fully.reepithelialized.wound,.and.reduce.the.related.trauma.and.
pain.in.patients.
A. wound. is. defined. as. breakage. in. the. continuity. of. skin. (Enoch. and.
Price. 2004).. It. can. affect. the. epithelial. layer. of. skin. or. also. the. underlying.
dermis,.subcutaneous.fat,.and.even.the.muscle,.nerves,.and.bone..Wounds.
are.classified.according.to.etiology.(caused.by.burns,.cuts,.friction.or.shear.
force,. pressure,. disease,. etc.),. anatomical. location,. or. duration. of. healing.
(acute and.chronic.wounds)..Wound.healing.is.a.complex.process.involving.
various. types. of. cells. (connective. tissue.and. immune.system. components).
and.controlled.by.a.variety.of.signal.molecules,.such.as.growth.factors,.proteinases. and. their. inhibitors,. cytokines,. and. other. inflammatory. response.
mediators..Acute.wound.healing.is.a.systematic.cascade.of.overlapping.but.
carefully.regulated.processes.that.requires.the.coordinated.completion.of.a.
variety.of.cellular.activities..These.processes,.which.are.triggered.by.tissue.
injury,.involve.four.phases:.hemostasis,.inflammation,.proliferation.(repair),.
and.remodeling..The.healing.of.acute.wounds.usually.takes.a.few.weeks.or.
months,.while.chronic.wounds.fail.to.heal.within.this.period.because.of.the.
Bacterial Cellulose
healing,.speeds.up.restoration.of.the.wounded.tissue.to.its.normal.state,.
and. significantly. reduces. pain;. (3). it. is. highly. porous,. absorbable,. and.
capable.of.donating.moisture.while.simultaneously.absorbing.exudates;.
(4).it.conforms.to.any.shape.of.wound.and.is.very.light.and.transparent,.
but. forms. a. mechanically. durable. and. tight. physical. barrier. to. microbial. contamination. and. additional. injuries. while. providing. gaseous.
exchange;.(5).it.allows.easy.and.painless.removal.of.wound.coverings;.
(6).it.is.sterilizable,.nondegradable.in.mammalian.systems,.flexible,.elastic,.and.available.in.any.size.and.shape;.(7).it.can.be.infused.with.other.
therapeutic. substances. without. deterioration. of. its. inherent. features;.
(8). its. properties. can. be. tailored. to. individual. needs. through. deliberate. changes. in. culture. conditions. of. bacterial. producers,. their. genetic.
modifications,.or.postculture.treatments.of.the.polymer;.and.(9).it.forms.
homogeneous. blends. with. other. biocompatible. polymers. like. alginate,.
hyaluronic. acid,. or. soluble. cellulose. derivatives.. BNC. wound. dressings.have.been.successfully.used.in.the.treatment.of.acute.and.chronic.
wounds..BNC.has.also.been.applied.as.a.scaffold.material.in.skin.grafts.
and.as.a.protective.membrane.in.end-to-end.nerve.repair..Cosmetic.uses.
of.BNC.include.manufacturing.of.moisturizing.facial.masks.and.creams,.
peeling.agents,.fingernail.polish,.and.as.a.base.for.artificial.nails.
Performance Requirements of Wound Dressings
The.basic.function.of.wound.dressings.is.promotion.of.rapid.wound.healing.with.a.focus.not.only.on.functional,.but.also.cosmetic.results..Modern.
wound.dressings.are.designed.to.accelerate.the.major.outcome.of.treatment,.
which.is.a.fully.reepithelialized.wound,.and.reduce.the.related.trauma.and.
pain.in.patients.
A. wound. is. defined. as. breakage. in. the. continuity. of. skin. (Enoch. and.
Price. 2004).. It. can. affect. the. epithelial. layer. of. skin. or. also. the. underlying.
dermis,.subcutaneous.fat,.and.even.the.muscle,.nerves,.and.bone..Wounds.
are.classified.according.to.etiology.(caused.by.burns,.cuts,.friction.or.shear.
force,. pressure,. disease,. etc.),. anatomical. location,. or. duration. of. healing.
(acute and.chronic.wounds)..Wound.healing.is.a.complex.process.involving.
various. types. of. cells. (connective. tissue.and. immune.system. components).
and.controlled.by.a.variety.of.signal.molecules,.such.as.growth.factors,.proteinases. and. their. inhibitors,. cytokines,. and. other. inflammatory. response.
mediators..Acute.wound.healing.is.a.systematic.cascade.of.overlapping.but.
carefully.regulated.processes.that.requires.the.coordinated.completion.of.a.
variety.of.cellular.activities..These.processes,.which.are.triggered.by.tissue.
injury,.involve.four.phases:.hemostasis,.inflammation,.proliferation.(repair),.
and.remodeling..The.healing.of.acute.wounds.usually.takes.a.few.weeks.or.
months,.while.chronic.wounds.fail.to.heal.within.this.period.because.of.the.