Figure 5.4
97
Bacterial Cellulose Surface Modifications
(a)
(b)
(c)
(d)
(e)
(f )
Figure 5.4
SEM.micrographs.of.BC.(a,.b),.BCP.(c,.d),.and.autoclaved.BCP.(e,.f)..(Reproduced.from.Pertile.
et.al..2010.)
of.the.material,.but.increased.the.porosity.and.surface.chemistry,.as.noticed.
by. the. presence. of. nitrogen.. The. scanning. electron. microscopy. (SEM).
observations. revealed. that. plasma. changes. BNC. morphology. (Figure 5.4)..
While. BNC. presents. relatively. low. porosity. and. a. tight. interfiber. contact,.
the.plasma.treatment.seems.to.disrupt.the.fibers.to.some.extent,.leading.to.
a. more. porous. and. rough. material.. The. results. also. showed. that. different.
cell.lines.display.a.different.behavior.in.contact.with.modified.biopolymers,.
once.the.modification.by.nitrogen.plasma.efficiently.improves.the.adhesion.
of.N1E-115.and.HMEC-1.cells,.although.in.the.case.of.the.3T3.fibroblasts,.no.
effect.was.observed.
Biodegradation
Tissue. engineering. scaffolds. are,. following. implantation,. subsequently.
replaced. by. native. tissue. as. they. are. gradually. removed. from. the. implant.
site.through.biodegradation..The.scaffold.degradation.rate.must.be.appropriate.to.the.regrowth.of.the.new.tissue.in.order.to.maintain.the.graft.structure.
and.mechanical.properties.and.to.avoid.failure.(Isenberg.et.al..2006;.Karande.
and.Agrawal.2008).
Cellulose.and.its.derivatives.are.degradable.by.several.bacteria.and.fungi.
that. synthesize. cellulose-specific. enzymes. (i.e.,. cellulases). (Tomsic. et. al..
97
Bacterial Cellulose Surface Modifications
(a)
(b)
(c)
(d)
(e)
(f )
Figure 5.4
SEM.micrographs.of.BC.(a,.b),.BCP.(c,.d),.and.autoclaved.BCP.(e,.f)..(Reproduced.from.Pertile.
et.al..2010.)
of.the.material,.but.increased.the.porosity.and.surface.chemistry,.as.noticed.
by. the. presence. of. nitrogen.. The. scanning. electron. microscopy. (SEM).
observations. revealed. that. plasma. changes. BNC. morphology. (Figure 5.4)..
While. BNC. presents. relatively. low. porosity. and. a. tight. interfiber. contact,.
the.plasma.treatment.seems.to.disrupt.the.fibers.to.some.extent,.leading.to.
a. more. porous. and. rough. material.. The. results. also. showed. that. different.
cell.lines.display.a.different.behavior.in.contact.with.modified.biopolymers,.
once.the.modification.by.nitrogen.plasma.efficiently.improves.the.adhesion.
of.N1E-115.and.HMEC-1.cells,.although.in.the.case.of.the.3T3.fibroblasts,.no.
effect.was.observed.
Biodegradation
Tissue. engineering. scaffolds. are,. following. implantation,. subsequently.
replaced. by. native. tissue. as. they. are. gradually. removed. from. the. implant.
site.through.biodegradation..The.scaffold.degradation.rate.must.be.appropriate.to.the.regrowth.of.the.new.tissue.in.order.to.maintain.the.graft.structure.
and.mechanical.properties.and.to.avoid.failure.(Isenberg.et.al..2006;.Karande.
and.Agrawal.2008).
Cellulose.and.its.derivatives.are.degradable.by.several.bacteria.and.fungi.
that. synthesize. cellulose-specific. enzymes. (i.e.,. cellulases). (Tomsic. et. al..