TABLe 11.3
Ca:P.Molar.Ratios.of.Different.BC.Templates.after.Five.Cycles.
of.Alternate.Soaking.in.Calcium.and.Phosphate.Solutions,.
as Measured.by.ICP-AES
Cycle 1
Cycle 3
Cycle 5
Native.BC
1.25.±.0.002
1.29.±.0.003
1.41.±.0.03
BC-TEMPO
1.23.±.0.001
1.31.±.0.002
1.46.±.0.01
BC-TEMPO-Ca
1.23.±.0.001
1.32.±.0.003
1.39.±.0.01
BC-GlcNAc
M1604-1604A
NA
NA
1.39.±.0.01
M1604-1010B
NA
NA
1.46.±.0.03
M1604-0416B
NA
NA
1.46.±.0.01
M0020-1604B
NA
NA
1.42.±.0.02
M0020-1010B
NA
NA
1.41.±.0.04
M0020-0416B
NA
NA
1.45.±.0.07
M1010-1010A
NA
NA
1.38.±.0.04
M0416-0416A
NA
NA
1.51.±.0.03
Source:. Adapted. from. T.. T.. Nge. et. al.,. Bacterial. cellulose-based.
. biomimetic.composites..In:.Biopolymers.(ISBN.978-953-307109-1,.InTech,.2010),.345–368,.with.permission.
233
Biomimetic Mineralization of Apatite on Bacterial Cellulose
type.of.starter.culture.(M1604,.M0020,.M0416).showed.a.Ca:P.ratio.(1.45–1.51).
higher.than.that.of.other.BC-GlcNAc.templates..The.highest.Ca:P.ratio.of.this.
sample.correlated.with.its.highest.deposit.weight,.as.shown.in.Figure 11.6.
Figure 11.6.shows.the.weight.gain.of.Ca-P.that.mineralized.on.various.BC.
templates.as.a.function.of.the.number.of.soaking.cycles..The.largest.deposit.
amounts.were.observed.in.the.BC-TEMPO,.BC-TEMPO-Ca,.and.native.BC.templates.throughout.the.soaking.cycles..Compared.to.the.BC-GlcNAc.templates,.
the.surface-modified.BC-TEMPO.and.BC-TEMPO-Ca.templates.were.characterized.by.the.largest.deposit.amounts..The.presence.of.. surface.. carboxylate.
groups.significantly.affects.not.only.the.crystal.nucleation.. process,.but.also.
the.amount.of.mineral.deposited.
It.was.found.that.the.presence.of.GlcNAc.on.the.surface.of.BC.micro. fibrils.
limits. the. rate. of. Ca-P. nucleation,. where. the. weight. gain. decreased. with.
increasing.incorporated.GlcNAc..Generally.the.ultrafine.network.with.highly.
hydrophilic.nature.of.BC.favors.the.infiltration.of.calcium.and.phosphorus.
fibril.surface..The.presence.of.incorporated.GlcNAc.somehow.hinders.mineral.nucleation,.although.the.detailed.mechanism.remains.to.be.elucidated..
As. a. consequence,. the. overall. rate. of. mineral. nucleation. on. the. surface. of.
BC. microfibrils. was. slow. and. the. mineral. deposition. observed. at. the. first.