Biomedical Engineering Reference
In-Depth Information
that cells grow and proliferate well on the surface (Fig. 12.3a). Cell
conluence appears and a sheet-like layer is formed on the coating
after the cells have been seeded for 7 days, as shown in Fig. 12.3b.
The cells seeded on the coating for 11 days have a more elongated
morphology and cover the whole surface (Fig. 12.3c).
Figure 12.3
SEM photographs of MG63 cells cultured on the plasma-
sprayed monoclinic zirconia coating for (a) 3 days, (b) 7
days, and (c) 11 days (the density of the cell suspension is
1 × 10
5
cell ml
-1
) [130].
The good cytocompatibility of the plasma-sprayed monoclinic
zirconia coating was possibly related to its surface nanostructure. It
was reported that nano-sized topography improved cell attachment,
adhesion, and proliferation on biomaterials [12, 127]. Webster
has proposed that the critical grain size for osteoblast adhesion is
49-67 nm for Al
2
O
3
, and 32-56 nm for TiO
2
[133]. The surface of
the plasma-sprayed monoclinic zirconia coating is constructed by
grains with the size range of 30-50 nm, which appears suitable for
cell attachment and viability.
The nanostructured surface that is composed of monoclinic
zirconia is believed to be crucial to its bioactivity. Morphological
observation and the cell proliferation test demonstrated that
osteoblast-like MG63 cells could attach to, adhere to and proliferate
well on the surface of the monoclinic zirconia coating, suggesting
possible applications in hard tissue replacements [130].
