Biomedical Engineering Reference
In-Depth Information
TABLE 5.2
Ion Concentrations of Simulated Body Fluids and Human Blood Plasma
Na
+
K
+
Mg
2+
Ca
2+
Cl
-
HCO
3
-
HPO
4
-
SO
4
2-
Human blood plasma
(Gamble 1967)
142.0
5.0
1.5
2.5
103.0
27.0
1.0
0.5
Ringer (Ringer 1883)
130
4.0
1.4
109.0
EBSS (Earle 1943)
143.5
5.37
0.8
1.8
123.5
26.2
1.0
0.8
HBSS (Hanks and
Wallace 1949; Hanks
1975)
142.1
5.33
0.9
1.26
146.8
4.2
0.78
0.41
SCS (Wen et al. 1997;
Habibovic et al.
2005)
140.4,
136.8
3.71
3.1
142.9,
144.5
1.86
Dulbecco's PBS
136.9
2.68
0.49
0.9
142.4
9.57
SBF (Kokubo et al.
1990)
142.0
5.0
1.5
2.5
148.8
4.2
1.0
0.5
mSBF (Kokubo 1991;
Ohtsuki et al. 1991;
Cho et al. 1995; Bigi
et al. 2000; Tas 2000;
Oyane et al. 2003)
142.0
5.0
1.0,
1.5
1.6,
2.5
147.8,
125.0,
124.5,
103.0
10.0,
27.0,
4.2
1.0
0.5
SBFx5 (Barrere et al.
2000; Habibovic et
al. 2002)
714.8,
704.2
7.5,
1.5
12.5
723.8,
711.8
21.0,
10.5
5.0
5.3.1 Biomineralization of Oxide Bioceramics
The surface functional groups, such as Si-OH, Ti-OH, Zr-OH, Ta-OH, and
Nb-OH, could induce the growth of calcium phosphate in a body environ-
ment (Lee et al. 2006). The surface potential of these functional groups is
initially negative owing to their isoelectric point in blood plasma (pH 7.4).
The nucleation is assumed to involve electrostatic interaction of the surface
functional groups with Ca
2+
and phosphate ions.
Preparation methods, crystallinity, and surface treatment will influence
the formation of these active groups in SBF. Sol-gel-derived silica can induce
the bonelike apatite precipitation on its surface, but silica glass and quartz
do not (Li et al. 1994). Hydrated silica in the fluid plays the key role in the
nucleation of apatite.
Sol-gel-derived TiO
2
can also induce the apatite formation because of
the formation of Ti-OH groups in SBF (Li et al. 1994; Wei et al. 2002). The
ability of apatite formation on titania surfaces with different crystallinity
is different (Uchida et al. 2001). Sol-gel-derived anatase is more active than
sol-gel-derived rutile and amorphous titania. Regarding alumina, although
sufficient Al-OH groups may remain in the alumina gel, they do not initiate
apatite generation when immersed in SBF (Li et al. 1994). That means not
all Ti-OH groups, but certain types of Ti-OH groups in a specific structural
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