Biomedical Engineering Reference
In-Depth Information
At the same solid-to-liquid ratio (wt/vol), the nanoparticulate
45S5 released approximately 10-fold more silica into the simulated
body luid than the conventional bioglass (Fig. 11.2). In contrast,
10-minute conventional bioglass supernatants contained substan-
tially more calcium, 158.5 ± 8.4 ppm vs. 31.2 ± 5.8 ppm. Nanometric
bioglass supernatants had a pH of 11.7, compared with 8.3 measured
in counterparts obtained from conventional bioglass suspensions.
Figure 11
.
2
Silicon and calcium contents as well as pH levels of 1:10
(wt/vol) suspension supernatants of conventional and
nanoparticulate bioglass in simulated body luid. Error bars
indicate standard deviations (
N
= 3) [33].
The current study showed a substantially higher release of
alkaline species and better antibacterial eficacy of bioactive glass
45S5 in nanoparticulate form, compared with the conventional
preparation [33]. The antibacterial effect of nanoparticulate bio-
active glass appears to be directly linked to its high surface area and
thus the resulting release of ionic components in solution. However,
the low concentration of calcium in nanometric 45S5 supernatants
suggests that calcium and phosphate released from this glass
preparation precipitate immediately [3]. The release of silica should
eventually result in the transformation of glass nanoparticles
into inert Ca-P shells, which can have a substantial potential to
(re)mineralize dentin [27, 33].
