88
Bacterial Cellulose
increased. with. numerous. lymphocytes,. monocyte/macrophage-like. cells,.
plasma.cells,.and.eosinophils.at.4.and.6 weeks..In.addition,.the.surface.of.the.
gel.blocks.implanted.into.the.subcutaneous.tissue.was.absorbed.(Tanabe.et al..
2008)..As.was.discussed.previously,.the.ultimate.stress.of.the.BNC-gelatin.gel.
block. dramatically. decreased. after. implantation,. while. obvious. deterioration. was. not. observed. in. the. BNC-PDMAAm. DN. gel. (Azuma. et. al.. 2007)..
These.facts.show.that.the.structure.composed.of.gelatin.was.absorbed.by.the.
previously. described. cell. activity.. This. fact. indicates. that. the. BNC-gelatin.
DN.gel.has.a.unique.absorbable.property.in.the.living.body..This.material.
has.the.potential.to.be.applied.as.an.absorbable.implant,.such.as.a.material.
for.drug.delivery.systems,.although.some.improvement.may.be.needed.to.
reduce.the.inflammatory.reaction.
Conclusions
The. BNC-based. DN. hydrogel. has. been. successfully. developed. from. natural. as. well. as. synthetic. polymers,. having. not. only. a. mechanical. strength.
as.great.as.several.megapascals,.on.the.order.of.that.for.cartilage,.ligament,.
and. tendon,. but. also. a. low. frictional. coefficient,. on. the. order. of. 10 −3 ,. high.
resistance.against.wear,.durability.to.endure.repetitive.stress,.and.resistant.
to.biodegradation.within.the.living.body..These.hydrogels.could.open.a.new.
era. of. soft. and. wet. materials. as. substitutes. for. biotissue. such. as. articular.
cartilage,.ligament,.tendon,.etc.,.and.could.be.a.potential.candidate.for.drug.
delivery.systems.in.the.living.body.
References
Athanasiou,.K..A.,.M..P..Rosenwasser,.J..A..Buckwalter,.T..I..Malinin,.and.Y..C..Mow..
1991.. Interspecies. comparisons. of. in. situ. intrinsic. mechanical. properties. of.
. distal.femoral.cartilage..J. Orthop. Res..9:330–340.
Azuma,.C.,.K..Yasuda,.and.Y..Tanabe..2007..Biodegradation.of.high-toughness.double.
network.hydrogels.as.potential.materials.for.artificial.cartilage..J. Biomed. Mater.
Res. A.81:373–380.
Baily,.S..J.,.ed..2003..Annual Book of ASTM Standards..West.Conshohocken,.PA:.American.
Society.for.Testing.and.Materials,.269–278.
Eisenberg,.S..R.,.and.A..J..Grodzinsky..1985..Swelling.of.articular.cartilage.and.other.
connective.tissues:.electromechanochemical.forces..J. Orthop. Res..3:148–159.
Gong,.J..P.,.Y..Katsuyama,.T..Kurokawa,.and.Y..Osada..2003..Double.network.. hydrogels.
with.extremely.high.mechanical.strength..Adv. Mater..15:1155–1158.
Bacterial Cellulose
increased. with. numerous. lymphocytes,. monocyte/macrophage-like. cells,.
plasma.cells,.and.eosinophils.at.4.and.6 weeks..In.addition,.the.surface.of.the.
gel.blocks.implanted.into.the.subcutaneous.tissue.was.absorbed.(Tanabe.et al..
2008)..As.was.discussed.previously,.the.ultimate.stress.of.the.BNC-gelatin.gel.
block. dramatically. decreased. after. implantation,. while. obvious. deterioration. was. not. observed. in. the. BNC-PDMAAm. DN. gel. (Azuma. et. al.. 2007)..
These.facts.show.that.the.structure.composed.of.gelatin.was.absorbed.by.the.
previously. described. cell. activity.. This. fact. indicates. that. the. BNC-gelatin.
DN.gel.has.a.unique.absorbable.property.in.the.living.body..This.material.
has.the.potential.to.be.applied.as.an.absorbable.implant,.such.as.a.material.
for.drug.delivery.systems,.although.some.improvement.may.be.needed.to.
reduce.the.inflammatory.reaction.
Conclusions
The. BNC-based. DN. hydrogel. has. been. successfully. developed. from. natural. as. well. as. synthetic. polymers,. having. not. only. a. mechanical. strength.
as.great.as.several.megapascals,.on.the.order.of.that.for.cartilage,.ligament,.
and. tendon,. but. also. a. low. frictional. coefficient,. on. the. order. of. 10 −3 ,. high.
resistance.against.wear,.durability.to.endure.repetitive.stress,.and.resistant.
to.biodegradation.within.the.living.body..These.hydrogels.could.open.a.new.
era. of. soft. and. wet. materials. as. substitutes. for. biotissue. such. as. articular.
cartilage,.ligament,.tendon,.etc.,.and.could.be.a.potential.candidate.for.drug.
delivery.systems.in.the.living.body.
References
Athanasiou,.K..A.,.M..P..Rosenwasser,.J..A..Buckwalter,.T..I..Malinin,.and.Y..C..Mow..
1991.. Interspecies. comparisons. of. in. situ. intrinsic. mechanical. properties. of.
. distal.femoral.cartilage..J. Orthop. Res..9:330–340.
Azuma,.C.,.K..Yasuda,.and.Y..Tanabe..2007..Biodegradation.of.high-toughness.double.
network.hydrogels.as.potential.materials.for.artificial.cartilage..J. Biomed. Mater.
Res. A.81:373–380.
Baily,.S..J.,.ed..2003..Annual Book of ASTM Standards..West.Conshohocken,.PA:.American.
Society.for.Testing.and.Materials,.269–278.
Eisenberg,.S..R.,.and.A..J..Grodzinsky..1985..Swelling.of.articular.cartilage.and.other.
connective.tissues:.electromechanochemical.forces..J. Orthop. Res..3:148–159.
Gong,.J..P.,.Y..Katsuyama,.T..Kurokawa,.and.Y..Osada..2003..Double.network.. hydrogels.
with.extremely.high.mechanical.strength..Adv. Mater..15:1155–1158.