Page 63 - Bio Engineering Approaches to Cancer Diagnosis and Treatment

3.5 Combination of imaging and immunodiagnostics 61

antibodies 10–15-fold more than usual immunosensors, therefore, providing signifi-
cant enhancements to the sensitivity of the immunosensor. These results indicate
that multiply-labeled detection probes that have been used in conjunction with elec-
trode surface modified increase their ability to capture a high-density antibody in
immunosensors. A comparison of immunosensors under similar assay conditions to
Rustling's group in detection of IL-6 has revealed that the AuNP modified platform
yielded a three-fold better detection limit than a SWCNT-based method [46].
Although this technique is acceptable, its accuracy does not exist for all fluids,
and other techniques in this area need to be combined with a method like magnetic
bead-based immunoassays. The use of magnetic beads to develop diagnostic devices
has become more popular. For example, magnetic beads have been used as substrates
for the capture of antibodies or for target antigens in immunoassays and enzyme-
linked immunoassays. Magnetic beads have several positive features, making it a
popular method. These include fast reaction kinetics compared to bulk-solid sur-
faces, high surface area per unit volume (owing to their small diameter), and good
stability. Moreover, the relative ease of surface modification with functional groups,
DNA, enzymes, or antibodies greatly contributes to the utility of beads in the devel-
opment of sensitive, rapid electrochemical immunoassay systems [41–44].
In the latest advancements in research, many immunosensors have been investi-
gated. And common among all of these are their high sensitivity in biomarker detec-
tion. The detection of multiple biomarkers in a noninvasive manner will be key in
facilitating prompt early-stage cancer diagnosis and reducing associated morbidity
and mortality.

3.5 Combination of imaging and immunodiagnostics
It is known that unusual genomic alteration in the levels of nucleic acids and chro-
matin cause to overexpression of proteins that has responsible to cell function. These
proteins might make a patterns that are relevant to malignant progression. In recent
studies, it has been seen that greater changes in nucleic acid expression has occurred
in end-stage patients with cancer. Therefore, identifying of changes in nucleic acids
are essential for cancer screening and monitoring. In addition, it has been reported
that some biomarkers such as EGFR, P53, cell regulatory protein Bcl-29, and cell
division cycle protein CDK-110 are overexpressed in specific cancers, and they may
be significant factors for specific cancers (such as lung cancer, breast cancer, and
ovarian cancer). As their roles in cancer have been identified, the detection and evalu-
ation of these nuclear biomarkers (nucleic acids and proteins) will help to clarify the
signaling pathways in tumorigenesis, and thus improve early-stage cancer diagnosis
[47].
Imaging is some ways to diagnose or to investigate the progression or improve-
ment of the disease. In cancer diagnosis, the goal of imaging is to detect malignant
cells from normal cells. Six techniques for assessing diseases are in the imaging
subdivisions, including CT, MRI, PET, US, SPECT, and visual detectors. In cancer