Biomedical Engineering Reference
In-Depth Information
Daniel et al. (2008) in their recent paper have reported the importance of probing the local
environment after tumor removal. Sampling of the local environment would indicate if the
neoplastic tissue has been completely removed. They point out that PTH (intraoperative
parathyroid hormone) is used in this manner. PTH levels decrease quickly, within 5-10
min, once the hypersecreting fluid has been removed. This is a clear marker of further
removal being necessary (
Lo et al., 2002; Sokol et al., 2004
). Daniel et al. (2008) report that
local biomarker concentrations are good indicators of the successful removal of different
types of tumors (
Sodlaczek et al., 2002; Baron et al., 2005a,b
). The implantable device that
Daniel et al. (2008) have developed could be left behind in the body after tumor resection.
They further point out that new tumor growth is difficult to identify from foreign lesions
(
Gomez-Rio et al., 2004
, 2008). Future devices that could be implanted for long periods
of time according to Daniel et al. (2008) will permit the evaluation of targeted therapies
and facilitate personalized cancer treatment (Chen, 2007;
Carney, 2007; Agarwal et al.,
2008; Takeguchi et al., 2008
).
Figure 6.11a
shows the binding (monitoring) of cancer in Mouse 1 to the implantable device
(
Daniel et al., 2009
). A dual-fractal analysis is required to adequately describe the binding
kinetics. The values of (a) the binding rate coefficient,
k
, and the fractal dimension,
D
f
, for
a single-fractal analysis, and (b) the binding rate coefficients,
k
1
and
k
2
, and the fractal
dimensions,
D
f1
and
D
f2
, for a dual-fractal analysis are given in
Tables 6.10
and
6.11
.
Figure 6.11b
and c show the binding (monitoring) of cancer in Mouse 2 and 3, respectively to
the implantable device (
Daniel et al., 2009
). A single-fractal analysis is adequate, in these
cases, to model the binding kinetics. The values of the binding rate coefficient,
k
, and the
fractal dimension,
D
f
, for a single-fractal analysis are given in
Tables 6.10
and
6.11
.
Suwansara-ard et al. (
2009
) have recently compared the performance of a SPR biosensor with
that of a capacitive immunosensor for the detection of CA 125 in human serum samples.
These authors point out that CA 125 is a tumor marker for ovarian cancer. They report that
CA 125 circulates in the serum of patients (
Endo et al., 1988
). For healthy humans, the con-
centration of CA 125 is less than 35 units/ml (
Wilder et al., 2003
).
Suwansara-ard et al.
(2009)
assert that the determination of CA 125 concentrations in human serum provides
information on the disease stage and aid in the monitoring of ovarian cancer.
Techniques have been used to detect and measure CA 125 levels that include radiometric
(
Marquette et al., 1987, 1997
), enzyme immunoassay (
Yan et al., 1999; Biomerieux, 2004;
Wu et al., 2006
).
Suwansara-ard et al. (2009)
point out that these techniques are time-
consuming, require several separation steps and specially equipped laboratories and skilled
personnel (
He et al., 2003; Lin and Ju, 2005
). Thus, the need for developing a simple detec-
tion technique, for example, an immunosensor for detecting CA 125 as suggested by
Suwansara-ard et al. (2009)
becomes imperative.
