# The Biocompatibility of Wireless Power Charging System on Human Neural Cells
## 3 Results
### The Effect of EMF on Cell Death and Inner Cellular Organization  
To analyze the ratio between live and apoptotic cells, flow cytometry analysis was used. We compared control group with exposed groups located as mentioned in Figure 6. The observed results are summarized in Table 2.  
Considering normal HA cells, we found that the highest percentage of viable cells (89.9%) was presented for the group located on the receiving coil equipped by magnetic shielding. In contrast, the control group had the lowest percentage of viable cells (87.3%). However, the number of dead cells was the lowest considering the control group (1.9%) compared to the group located on shielded receiver (3.0%). However, these differences are minimal and such variability is accepted from a biological point of view. In addition, cells that are metabolically and mitotically active also have a certain minimum percentage of dead or apoptotic cells. We obtained very similar values in the case of cancer cells (T98G, SH-SYSY). The percentage distribution of cells in followed processes (apoptosis, necrosis or viable cells) is comparable and independent of type of cell line. Overall, SH-SYSY cells showed slightly lower values at percentage of viable cells, which may be due to their biological nature, or the fact that after 44 h of regeneration, the cells were slightly overgrown and some of them could naturally activate cell death. Based on the results it could be concluded that the group of dead cells represents the lowest percentage within each group, thus supporting the fact that the test conditions did not result in increased death of cells.  
We evaluated the effect of EMF on cytoskeletal organization of neural cells (87 kHz, 1.5 kW, 30 min) and followed by 44 h of regeneration under standard conditions (Figure 12). The control group of healthy HA cells had normal structures that exhibit sharply rounded nuclei with noncondensed chromatin. The impact of EMF did not result in the visualization of fragmentation of nuclei into small apoptotic bodies, as evidence of the negative effect of radiation on cells. The actin fibers of the cytoskeleton of the cells were dense, distinct and organized in parallel bundles. Moreover, the structure of the cytoskeleton is very compact and markedly limited, no loosened or disassembled fibers were observed.  
The cancer cells (T98G, SH-SYSY) after exposure had preserved similar inner cellular structures compared to control groups. We did not observe any changes in cytoskeletal structures and organization, which is location independent within the WPT system, neither between normal and cancer cells.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **Location** & **Living** & **Early** & **Late** & **Dead** \\  & **Cells** & **Apoptotic** & **Apoptotic** & **Cells** \\ \hline \multirow{3}{*}{**HA**} & Control & 87.3\% & 4.7\% & 6.2\% & 1.8\% \\  & Coil & 88.5\% & 4.6\% & 4.5\% & 2.3\% \\  & Shielded & 89.9\% & 3.5\% & 3.5\% & 3.0\% \\ \hline \multirow{3}{*}{**T98G**} & Control & 86.2\% & 4.1\% & 6.5\% & 3.2\% \\  & Coil & 86.1\% & 4.0\% & 6.5\% & 3.3\% \\  & Shielded & 87.3\% & 4.0\% & 5.7\% & 3.0\% \\ \hline \multirow{3}{*}{**SH-SYSY**} & Control & 84.9\% & 4.3\% & 7.1\% & 3.7\% \\  & Coil & 83.7\% & 4.8\% & 8.5\% & 3.0\% \\ \cline{1-1}  & Shielded & 87.8\% & 3.0\% & 5.1\% & 4.1\% \\ \hline \hline \end{tabular}
\end{table}
Table 2: The effect of EMF (87 kHz, 30 min) on neural cell death analyzed by flow cytometry. After exposure, cells were regenerated for another 44 h and analyzed by Annexin assay.