Biomedical Engineering Reference
In-Depth Information
10
Initial cell seeding
8
6
Media change
Position
2.5 cm
4.5
1.5
0.5
4
2
0
0
10
20
30
40
50
60
Culture time (h)
FIGURE 3.10
Fibroblast cell proliferation rates on wettability chemogradient PE surfaces (24-60 h culture).
TABLE 3.8
Proliferation Rates of Fibroblast
Cells on Wettability Gradient PE Surfaces
Positions
(cm)
Contact
Angle (°)
Cell Proliferation
Rate (#cell/h cm
2
)
2.5
55
1111
4.5
45
924
1.5
67
838
0.5
85
734
Note:
24-60 h culture.
To observe the effect of serum proteins on the cell adhesion and growth behaviors, fetal bovine serum,
which contains more than 200 kinds of different proteins, was adsorbed onto the wettability gradient
PE surfaces for 1 h at 37°C. Figure 3.11 shows the relative adsorbed amount of serum proteins on the
wettability gradient surfaces determined by ESCA. The maximum adsorption of the proteins appeared
at around the 2.5 cm position, which is the same trend as the cell adhesion, growth, and migration
behaviors. It can be explained that preferential adsorption of some serum proteins, like fibronectin and
vitronectin from culture medium, onto the moderately wettable surfaces may be a reason for better
cell adhesion, spreading, and growth. Proteins like fibronectin and vitronectin are well known as cell-
adhesive proteins. Cells attached on surfaces are spread only when they are compatible on the surfaces.
It seems that surface wettability plays an important role for cell adhesion, spreading, and migration.
Also investigated were (1) platelet adhesion on wettability chemogradient (Lee and Lee, 1998), (2)
cell interaction on microgrooved PE surfaces (groove depth, 0.5 μm; groove width, 0.45 μm; and pitch,
0.9 μm) with wettability chemogradient (Khang et al., 1997c), (3) detachment of human endothelial
under flow from wettability gradient surface with different functional groups (Raurdy et al., 1997), (4)
cell interaction on microporous polycarbonate membrane with wettability chemogradient (Lee et al.,
1999b), and (5) cell interaction on poly(lactide-
co
-glycolide) surface with wettability chemogradient
(Khang et al., 1999a).
During the last several years, “chemogradient surfaces” have evolved into easier and more popular
tools for the study of protein adsorption and platelet or cell interactions continuously which relate to
