Biomedical Engineering Reference
In-Depth Information
140
120
100
80
60
40
20
0
a-C
a-CN
SS
Ti
FIGURE 2.32
Adhesion of osteoblasts on the a-C, a-CN, Ti, and bare stainless steel substrates after 24 h. (Reprinted with per-
mission from Olivares et al.,
Surf. Coat. Technol.
, 177-178, 758, 2004.)
energy) and highest polar component of the surface energy among the three films. It
also has the highest number of adhering cells on its surface (see Figure 2.33). It is once
again shown that the adhesion of biological cells can be affected by modifying the contact
angle and surface energy parameter. Pure ta-C with favorable physicochemical properties
seemed to be most suitable for Saos-2 adhesion.
An evaluation on MC3T3-E1 osteoblast-like cells' response to a-C:H was done [119]. The
a-C:H and deuterated a-C:H films were deposited by PECVD, and three types of precur-
sor gas were applied for deposition: pure methane (CH
4
), pure deuterated methane (CD
4
),
and their half/half mixture. All surface treatments were performed under two different
self-bias voltages (
V
sb
): −400 and −600 V. The a-C:H films deposited under the
V
sb
of −600 V
in pure methane (600CH4) or in pure deuterated methane (600CD4) offered a significantly
higher cell proliferation rate as compared to silicon substrate. SEM observations confirmed
that the optimal cell adhesion behavior, among all the treated surfaces, occurred on the
surface of the 600CH4 and 600CD4 groups, which showed increased amounts of filopodia
100,000
* *
* *
80,000
*
*
After 24 h
60,000
After 48 h
40,000
20,000
AD
AD-PDMS AD-Ti
Si
FIGURE 2.33
Cell proliferation for different coatings and silicon. Number of viable cells was determined at 24 and 48 h using
MTT assay and a standard curve normalized to number of osteoblast-like cells. *Significant difference
p
<
0.05, **Significant difference
p
< 0.01. Error bars indicate standard deviations. (Reprinted with permission from
Myllymaa et al.,
Diamond Rel. Mater.
, 18, 1294, 2009.)
