Biomedical Engineering Reference
In-Depth Information
TABLE 8.5 MTT Assay for IOMNP Toxicity to U937 Cells
Cell-IOMNP incubation period
IOMNP, mg/mL
1 h
4 h
24 h
IOMNP with COOH on the surface, 5 nm diameter
0.025
0.224 ± 0.038
0.216 ± 0.015
0.207 ± 0.020
0.5
0.235 ± 0.019
0.243 ± 0.043
0.214 ± 0.014
1
0.210 ± 0.025
0.261 ± 0.019
0.216 ± 0.021
IOMNP with COOH on the surface, 10 nm diameter
0.025
0.282 ± 0.025
0.261 ± 0.015
0.237 ± 0.033
0.5
0.218 ± 0.016
0.243 ± 0.043
0.225 ± 0.015
2
0.211 ± 0.022
0.206 ± 0.019
0.217 ± 0.028
Control
None
0.246 ± 0.004
0.220 ± 0.025
0.232 ± 0.051
(8)
Add 50 uL of DAPI solution.
(9)
Incubate at 37 °C and 5% CO
2
for 5 min.
(10)
Remove the DPBS with DAPI.
(11)
Rinse the cells with 1 × DPBS.
(12)
Place 500 uL 1 × DPBS and scan the cells under the microscope.
(13)
Scan each cover slip under the microscope across one edge to the other
over three sections in the middle to count the number of dead cells and the
number of live cells (see Figure 8.4).
(14)
Calculate the % of dead cells.
The results in
Table 8.6
indicated that both the 5 and 10 nm diameter IOMNPs
showed % cell death at the highest concentration tested that are similar to those
of the control that were not exposed to any NM.
131
This observation is signifi-
cant for the growing applications of IOMNPs in medicine.
The alternative protocol for assessing NM toxicity in cells in vitro is easy
to use and very inexpensive. Although it requires time, multiple scans of the
cells over the glass cover slip can be performed for better sensitivity. The only
instrument required is an optical microscope that can differentiate between blue
stained cells and non-stained cells.
8.2.5 Silver NPs Toxicity
Silver nanoparticles (AgNPs) show low toxicity to human cells but they have
effective broad-spectrum activity against bacteria and a far lesser probability
