Biomedical Engineering Reference
In-Depth Information
TABLE 1.3
Classes of Materials That Can Be Coated with Different Calcium-Phosphate Coating Techniques
CoatingTechnique
Metals
Ceramics
Polymers
Examples
Plasma spraying
×
de Groot et al. 1987; Klein et al. 1991
Sputter coating
×
×
Ong and Lucas 1994; Feddes et al. 2004
Pulsed laser deposition
Baeri et al. 1992; Antonov et al. 1998;
Honstu et al. 1997
×
×
×
Electrophoretic deposition
×
×
Ducheyne et al. 1990; Yamashita et al. 1998
Sol-gel
×
×
Kaneko et al. 2009; Montenero et al. 2000
Hot isostatic pressing
×
×
Herø et al. 1994; Li, Liao, and Hermansson
1996
Dynamic mixing method
×
Yoshinari, Ohtsuka, and Dérand 1994
Biomimetic coating
×
×
×
Tanahashi et al. 1994; Habibovic et al. 2002;
Abe, Kokubo, and Yamamuro 1990
this method is expensive. A promising alternate technique is biomimetic precipitation of
apatite onto implant surfaces using supersaturated salt solutions known as simulated body
fluids (SBFs) (Abe, Kokubo, and Yamamuro 1990). These SBFs have similar ionic constitu-
tions to blood plasma and form carbonated apatites at physiologic temperatures, similar to
those found in bone (Table 1.4). Commonly used SBF coating regimens for different mate-
rial applications are listed in Table 1.5.
The mechanism of formation of BLM can be generally outlined as (1) functionalization of
the substrate to obtain a negatively charged surface, (2) nucleation by chelation of precur-
sor Ca 2+ ions to these negatively charged groups, and (3) growth of the BLM layer (Murphy,
Kohn, and Mooney 2000a). Surface functionalization can be achieved by several meth-
ods, such as grafting functional groups, alkaline treatments, aqueous hydrolysis, heat
treatments, and glow discharge treatment in oxygen (Murphy, Kohn, and Mooney 2000a;
Segvich et al. 2008; Kokubo 1996; Tanahashi et al. 1995; Luong et al. 2006; Tanahashi and
Matsuda 1997). The heterogeneous precipitation of biomineral from solution occurs when
the precursor-substrate interfacial energy is lower than the precursor-solution energy,
TABLE 1.4
Chemical Composition (in mM) of Different Types of SBFs
TypeofSBF
Na +
K +
Mg 2+
Ca 2+
Cl
HCO 3−
HPO 4 2−
SO 4 2−
Reference
1× SBF
142.0
5.0
1.5
2.5
148.8
4.2
1.0
0.5
Abe, Kokubo, and
Yamamuro 1990
Revised SBF
(r-SBF)
142.0
5.0
1.5
2.5
103.0
27.0
1.0
0.5
Oyane et al. 2003
Newly improved
SBF (n-SBF)
142.0
5.0
1.5
2.5
103.0
4.2
1.0
0.5
Takadama et al.
2004
1× mSBF
145.2
6.0
1.5
5.0
157.0
4.2
2.0
0.5
Luong et al. 2006
2× SBF
282.0
10.0
3.0
5.0
304.0
8.4
2.0
1.0
Shin, Jayasuriya,
and Kohn 2007
710.0
25.0
12.7
7.7
739.7
21.0
5.0
2.5
Chen et al. 2008
5× SBF
Human plasma
142.0
5.0
2.5
1.5
103.0
27.0
1.0
0.5
Abe, Kokubo, and
Yamamuro 1990
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