# Comparison of Genotoxicity and Pulmonary Toxicity Study of Modified SiO2 Nanomaterials
## 3 Results
### Acute Pulmonary Toxicity Test (14 D)  
There was no significant gross lesion in the lungs of all the treatment groups on Day 14 (Figure 5). However, in histopathologic examination, minimal to moderate macrophage aggregations were observed in the lungs of the SA (Figure 6B), mSA (Figure 6C), and SB (Figure 6D) groups at high incidence. In the pathologic scores of macrophage aggregations and total scores, the SA, mSA, and SB groups were significantly increased compared to the negative control (Figure 6A). In addition to macrophage aggregations, minimal to slight alveolar granulomatous inflammation was noticed in the lungs of SB group. It is noteworthy that mSB (Figure 6E) induced no significant lesions, and all the pathologic scores of lungs were significantly lower than the SB group (Figure 6, Table 12). The neutrophil count of BALF of SB group was significantly increased compared to the negative control (Table 13). \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multicolumn{6}{c}{**Pathological Scores**} \\ \hline \multirow{2}{*}{**Organ**} & \multirow{2}{*}{**Lesions**} & \multicolumn{4}{c}{**Group**} \\ \cline{3-6}  & & **NC** & **SA** & **mSAL** & **SB** & **mSB** \\ \hline Lung & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\ \end{tabular}  
* NC: negative control, R.D.W, 0.5 mL/kg bw, i.t.; SA: sample A, 2.58 mg/kg bw, 80\(\times\) diluted, 0.5 mL/kg bw, i.t.; mSAL: modified sample A low dose, 0.06 mg/kg bw, 320\(\times\) diluted, 0.5 mL/kg bw, i.t.; SB: sample B, 2.24 mg/kg bw, 80\(\times\) diluted, 0.5 mL/kg bw, i.t.; mSB: modified sample B, 0.24 mg/kg bw, 80\(\times\) diluted, 0.5 mL/kg bw, i.t. 2 Degree of lesions was graded from one to five depending on severity: 1 = minimal (<1%); 2 = slight (1-25%); 3 = moderate (26–50%); 4 = moderate/severe (51–75%); 5 = severe/high (76–100%). 3 Data are expressed as the mean \(\pm\) SD (n = 5–6). 4 Total score = sum of all the pathological score of the left lobe of lung.
* Significant difference between the control and treated groups at \(p<0.05\). 5 Significant difference between the SA and mSAL groups at \(p<0.05\). 5 Significant difference between the SB and mSB groups at \(p<0.05\). 5  
\end{table} 
Table 10: _Cont._Figure 5: Gross findings of lungs of rats after intratracheal instillation with unmodified and modified nano-silica in the acute pulmonary toxicity on Day 14. Normal gross of lung of control group (**A**), SA group (**B**), mSA group (**C**), SB group (**D**), and mSB group (**E**) were found in rats. Negative control: R.D.W, 0.5 mL/kg bw, i.t. ; SA: sample A, 0.645 mg/kg bw, 320\(\times\) diluted, 0.5 mL/kg bw, i.t. ; mSA: modified sample, 0.06 mg/kg bw, 320\(\times\) diluted, 0.5 mL/kg bw, i.t. ; SB: sample B, 2.24 mg/kg bw, 80\(\times\) diluted, 0.5 mL/kg bw, i.t. ; mSB: modified sample B, 0.24 mg/kg bw, 80\(\times\) diluted, 0.5 mL/kg bw, i.t. Figure 6: _Cont._ \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{6}{c}{**Pathological Incidence**} \\ \hline \hline
**Organ** & **Lesions** & \multicolumn{6}{c}{**Group**} \\ \cline{3-6}  & **NC 1**  & \multicolumn{6}{c}{**mSB**} \\ \hline Lung & Aggregate of macrophage, alveolar multifocal & - & 4/5 2  & \multicolumn{6}{c}{**mSB**} \\ \hline Lung, left lobe & Aggregate of macrophage, alveolar multifocal & 0.0 \(\pm\) 0.0  & \multicolumn{6}{c}{**mSB**} \\ \hline Granulomatous inflammation, alveolar, focal & 0.0 \(\pm\) 0.0 & 0.0 \(\pm\) 0.0 & 0.0 \(\pm\) 0.0 & 1.6 \(\pm\) 0.5 *  & 0.0 \(\pm\) 0.0 & 2.0 \(\pm\) 1.5 *  & 1.6 \(\pm\) 0.5 *  & 0.8 \(\pm\) 0.8 *  & 0.0 \(\pm\) 0.0 \\ \hline Total score & 0.0 \(\pm\) 0.0 & 0.2 \(\pm\) 1.5 *  & 1.6 \(\pm\) 0.5 *  & 0.8 \(\pm\) 0.8 *  & 0.0 \(\pm\) 0.0 *  \\ \hline \hline \end{tabular}
\end{table} 
Table 12: Summary of pathological incidence and pathological scores of rats after intratracheal instilled with unmodified and modified nano silica on Day 14.