Titanium Phosphate Glass Microspheres as Microcarriers for In Vitro Bone Cell Tissue Engineering - Biointerfaces: Where Material Meets Biology - page 127

5.4.5 Expected Outcomes and Other Considerations
The above approaches should yield layers of cells on the glass microsphere
surface that can be viewed by microscopic techniques such as SEM, confocal
laser scanning microscopy, fluorescence microscopy and so on. The effect of
the glass composition on the attachment and proliferation of cells on the
microsphere surface is quite pronounced. For instance, when MG63 cells are
cultured on titanium glass microspheres containing 0-5 mol% TiO 2 over a
period of 4 days, cells are clearly visible on the microspheres containing
3 mol% TiO 2 or higher, whereas no cells can be found on those containing 0
or 1 mol% TiO 2 (Figure 5.6). In agreement with the degradation study re-
sults, the 0 mol% TiO 2 glass microspheres show the highest degradation in
the cell culture medium and have almost completely disintegrated by day 4.
The 1 mol% TiO 2 microspheres show less degradation than the Ti0 micro-
spheres, yet considerable changes in surface morphology are observed in the
form of irregular cracks on the surface, and no adherent cells can be dis-
cerned. In contrast, both the 3 and 5 mol% TiO 2 microspheres show sig-
nificant numbers of cells on their surface. Most of the microspheres appear
to be covered by a finite, countable number of cells that envelop the
microsphere surface. In many cases, cells on different microspheres appear
to be joined to each other by means of processes. Thus, the 3 and 5 mol%

d n 3 r 4 n g | 3

.

Figure 5.6 Scanning electron microscopy images of MG63 cells cultured on tita-

nium phosphate glass microspheres containing (a) 0 mol% TiO 2 ,
(b) 1 mol% TiO 2 , (c) 3 mol% TiO 2 and (d) 5 mol% TiO 2 over a 4-day
period. The magnification in all the images is 5005.