Biomedical Engineering Reference
In-Depth Information
different results. In general, the particles prepared using Tween 80 were more spherically
shaped compared to those prepared with Pluronic F68. Figure 12 displays two examples of
particles obtained from the factorial design, prepared under the same conditions, but with
different surfactants.
The spherical and nanometric particles presented in Figure 12b meet the requirements of the
morphology desired for a DDS. This morphology allows for different administration routes,
including the intravenous route.
2.2 Preparation of biomaterials by the non-hydrolytic sol-gel process
The non-hydrolytic sol-gel process is another route for the production of materials for
bioapplications such as dental and osseous substitutes. Here the preparation and
characterization of the glass ionomer by this methodology is described. Calcium
fluoroaluminosilicate glass containing phosphorus and sodium (Ca-FAlSi) consists of an
inorganic polymeric network (mixed oxide) embedded in an aluminum and silicon matrix,
comprising an amorphous structure. This material is currently employed in dentistry as
restorative designated glass ionomer cement [76, 77]. Firstly, the calcium-
fluoroaluminosilicate glass was prepared in oven-dried glassware and AlCl
3
, SiCl
4
, CaF
2
,
AlF
3
, NaF, AlPO
4
, and ethanol were reacted in reflux under argon atmosphere [53]. The
27
Al
NMR results revealed the coordination of aluminum. Figure 13 shows the NMR spectrum of
the calcium-fluoroaluminosilicate glass dried at 50°C and submitted to heat treatment at
1000°C.
59.4
0.0
10.4
140.3
b
a
-200
-150
-100
-50
0
50
100
150
200
Chemical Shift / ppm
Fig. 13.
27
Al NMR spectrum of the sample dried at 50°C and treated at 1000
o
C.
