Barbieri Thesis - BioMedical Materials program (BMM)
Barbieri Thesis - BioMedical Materials program (BMM)
Barbieri Thesis - BioMedical Materials program (BMM)
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
CChapter<br />
2 – The role r of gels in innstructive<br />
puttie es<br />
2.3. Resuults<br />
2.3.1. Pollymer<br />
gels andd<br />
biphasic cal lcium phosphaate<br />
ceramic<br />
The compposition<br />
of thee<br />
polymer gels<br />
is illustratedd<br />
in Table 1. As A expected, chemical<br />
analysis with XRD connfirmed<br />
that the t BCP grannules<br />
were co omposed of 80±5% 8 of<br />
hydroxyapatite<br />
(HA) annd<br />
20±5% of –tricalcium pphosphate<br />
(– –TCP) (Figure e 1). SEM<br />
confirmedd<br />
that the micro–structured<br />
d surface wass<br />
comprised of small gra ains (size<br />
0.9±0.2 m)<br />
and nummerous<br />
micro– –pores with ssize<br />
ranging between b 0.55 and 1.06<br />
m (Figure<br />
1).<br />
Figure 1. CCharacterization<br />
oof<br />
BCP granules. . (a) XRD spectruum<br />
showing the two t phases (HA and a –TCP)<br />
composing BCP. (b) SEM picture<br />
of the micr ro–structured surrface<br />
of BCP gran nules.<br />
After commbining<br />
the poolymer<br />
gels wit th BCP granules,<br />
the five putties<br />
appeare ed as soft<br />
and mouldable<br />
massees<br />
of ceramic c granules stuuck<br />
together. The gel betw ween the<br />
particles wwas<br />
not visible<br />
except for alginate a gel, wwhich<br />
had brow wnish colour (F Figure 2).<br />
As it mayy<br />
be observedd,<br />
the putties had h different ggel/BCP<br />
volu ume ratios be ecause of<br />
the differeent<br />
viscositiess<br />
of the gels used u (Table 22),<br />
which originated<br />
putties with very<br />
different hhandling<br />
propperties.<br />
Using a stainless stteel<br />
spoon at room tempera ature, the<br />
CMC–bassed<br />
putty wass<br />
easy to hand dle without loss<br />
of particles s, while those e made of<br />
PLU, PVAA<br />
and ALG geels<br />
were stick ker and thus mmore<br />
difficult to shape. CHI<br />
gel was<br />
not as viiscous<br />
as thee<br />
other four and a the correesponding<br />
putties<br />
could lo ose some<br />
ceramic ggranules<br />
from the mass whe en shaped.<br />
2.3.2. Disssolution<br />
of thee<br />
gels and dis sintegration of f the putties<br />
Visual insspection<br />
and quantitative estimation e of the gel dissolution<br />
rates s showed<br />
that CMCC,<br />
PLU and ALG–based<br />
pu utties lost theirr<br />
shape within n 30 minutes and BCP<br />
granules were loose in one day, while<br />
CHI gel dissolved<br />
at a slo ower rate (Fig gure 2). In<br />
particularr,<br />
ALG putty ddisintegrated<br />
quicker indicaating<br />
ALG gel<br />
dissolved fa aster than<br />
CMC andd<br />
PLU. On tthe<br />
contrary, PVA putty reetained<br />
its sh hape over tw wo weeks<br />
indicatingg<br />
slow dissoluttion<br />
rate of the e gel.<br />
32
Change language