3 Bio-microelectromechanical Systems (BioMEMS) in Bio-sensing …
89
Fig. 3.6 a CELL chip
b Concentration gradient
generation chip exemplifying
the 5 concentrations of
CAMPT used by using a dye
(Montón et al. 2017)
(Ann-V) can be conjugated to the QD. Ann-V has a high affinity towards Ps, acting
as intermediary link between QDs and the apoptotic cells.
In the microfluidic device investigated by Montón et. al. (2017), two stages are
proposed, each with their respective LOC, to cultivate, mark, and identify induction of
apoptosis in cancer cells. The CELL chip proposed by the authors had different chambers for cell seeding (Fig. 3.6a). To achieve a monolayer on the CELL chip, samples
were incubated for 24 h prior to exposure to camptothecin (CAMPT). Subsequently,
the previously conjugated Ann-V-QD (in a separate PDMS device) was pumped
into the CELL chip. This procedure was repeated for 5 different concentrations of
CAMPT. The results showed a correlation between doses of the cancer treatment
chemical and the Ann-V-QD labeled cells, establishing this device as a reliable tool
for the bioassays. In the second design in order to induce cellular death, CAMPT was
used again, however, it was diluted to a concentration gradient allowing the device
to expose cancer cells to different CAMPT doses (Fig. 3.6b).
Modularity grants a high degree of adaptability to assays conducted within LOC
devices at the cost of increased complexity. An approach to effectively implement
multi-step assays inside a device was reported for determining insulin level and
insulin-like factors in type 1 diabetes (T1D) patients (Cohen 2017). The proposed
LOC relied on fluid mixing through the induction of transverse flow via serpentine geometries. The sample was introduced to the device via the inlet farthermost
from the single outlet of the chip. The sample, once inside the device, was exposed
to microspheres previously functionalized with antibodies specific to insulin and
insulin-like factors. Taking advantage of the high surface area of spheres, exposure
to analyte was magnified, reducing the time needed to achieve satisfactory mixing.
89
Fig. 3.6 a CELL chip
b Concentration gradient
generation chip exemplifying
the 5 concentrations of
CAMPT used by using a dye
(Montón et al. 2017)
(Ann-V) can be conjugated to the QD. Ann-V has a high affinity towards Ps, acting
as intermediary link between QDs and the apoptotic cells.
In the microfluidic device investigated by Montón et. al. (2017), two stages are
proposed, each with their respective LOC, to cultivate, mark, and identify induction of
apoptosis in cancer cells. The CELL chip proposed by the authors had different chambers for cell seeding (Fig. 3.6a). To achieve a monolayer on the CELL chip, samples
were incubated for 24 h prior to exposure to camptothecin (CAMPT). Subsequently,
the previously conjugated Ann-V-QD (in a separate PDMS device) was pumped
into the CELL chip. This procedure was repeated for 5 different concentrations of
CAMPT. The results showed a correlation between doses of the cancer treatment
chemical and the Ann-V-QD labeled cells, establishing this device as a reliable tool
for the bioassays. In the second design in order to induce cellular death, CAMPT was
used again, however, it was diluted to a concentration gradient allowing the device
to expose cancer cells to different CAMPT doses (Fig. 3.6b).
Modularity grants a high degree of adaptability to assays conducted within LOC
devices at the cost of increased complexity. An approach to effectively implement
multi-step assays inside a device was reported for determining insulin level and
insulin-like factors in type 1 diabetes (T1D) patients (Cohen 2017). The proposed
LOC relied on fluid mixing through the induction of transverse flow via serpentine geometries. The sample was introduced to the device via the inlet farthermost
from the single outlet of the chip. The sample, once inside the device, was exposed
to microspheres previously functionalized with antibodies specific to insulin and
insulin-like factors. Taking advantage of the high surface area of spheres, exposure
to analyte was magnified, reducing the time needed to achieve satisfactory mixing.