# Comparison of Genotoxicity and Pulmonary Toxicity Study of Modified SiO2 Nanomaterials
## 3 Results
### Acute Pulmonary Toxicity Test (1 D)  
The gross lesions of the lungs of the rats in negative control, SA, mSAH, mSAL, SB, and mSB groups were observed. Hemorrhage and emphysema in several lung lobes were noticed in all the treatment groups. The mSAH group showed most severe gross lesions and highest mortality (Figure 2, Table 9). Under histopathologic examination, the SA (Figure 3B), mSAL (Figure 3C), and SB (Figure 3D) groups showed higher pathological incidence in edema, necrosis, and inflammation and significantly higher total scores than the negative control (Figure 3A). The SB induced significantly more severe edema, inflammation, and necrosis than mSB (Figure 3E) in rat lungs. The lung weight might increase when the edema and inflammation in lung was induced by pulmonary damage (Figure 4, Table 10). The relative lung weight of rats in SA, mSAL, and SB groups was significantly increased compared to the negative control. In addition, the relative lung weight of the rats in SB group was significantly higher than in mSB group (Figure 4A). The total WBC, macrophage, neutrophil, and lymphocyte count of BALF in SA, mSAL, and SB groups were significantly increased compared to the negative control. It is noteworthy that the mSB did not significantly increase the inflammation cell count in the lung compared to the negative control, and the inflammation cell count was significantly lower than the SB group. On the other hand, in comparison with SA, the mSAL induced significantly more WBC accumulation in rat lungs (Table 11). The protein concentration of BALF in the SA and mSAL groups was significantly increased compared to the negative control (Figure 4B). The TNF-\(\alpha\) concentration of BALF in the mSAL and SB groups was significantly increased compared to the negative control (Figure 4C). \begin{table}
\begin{tabular}{c c c} \hline \hline  & **Group/** & **RETs/NCEs 1** & **Mn-RETs/RETs** \\  & **Intervals** & **(\%)** & **(\%)** \\ \hline \hline
48 h & & \\  & NC 2 & 37.2 \(\pm\) 7.4 3 [FOOTNOTE:3]Footnote 3: RETs: reticulocytes; NCEs: normochromatic erythrocytes; M-RETs: micronucleated reticulocytes. 2 NC: negative control, R.D.W, 0.5 mL/kg bw, i,t; PC: positive control, cyclophosphamide, 20 mg/kg bw, 10 mL/kg bw, i,p; SA: sample A, 0.645 mg/kg bw, 320\(\times\) diluted, 0.5 mL/kg bw, i,t; mSA: modified sample A, 0.06 mg/kg bw, 320\(\times\) diluted, 0.5 mL/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. 3 Data are expressed as the mean \(\pm\) SD (n = 4-5). 4 Significant difference in comparison with the negative control and treated groups at \(p<\) 0.05. 4 Significant difference in comparison with the SB and mSB groups at \(p<\) 0.05. Group: SA: sample A unmodified; mSA: modified sample A; SB: sample B; mSB: modified sample B. \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Changes of reticulocytes with micronucleeli in the peripheral blood of rats after intratracheal instillation with unmodified and modified nano-silica in the peripheral blood micronucle test. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Group**} & **Animal** & **Clinical** & \multicolumn{3}{c}{**Hours After Treatment**} & **Mortality** \\  & **No.** & **Sign** & **1** & **12** & **24** & **(\%) 3** \\ \hline NC 1 [FOOTNOTE:1]Footnote 1: NC: negative control, R.D.W, 0.5 mL/kg bw, it.; SA: sample A, 2.58 mg/kg bw, 80\(\times\) diluted, 0.5 mL/kg bw, it.; mSAH: modified sample A high dose, 0.24 mg/kg bw, 80\(\times\) diluted, 0.5 mL/kg bw, it.; mSAL: modified sample A low dose, 0.06 mg/kg bw, 320\(\times\) diluted, 0.5 mL/kg bw, it.; SB: sample B, 2.24 mg/kg bw, 80\(\times\) diluted, 0.5 mL/kg bw, it.; mSB: modified sample B, 0.24 mg/kg bw, 80\(\times\) diluted, 0.5 mL/kg bw, it. 2 Number of rats observed. \\ SB & 6 & Normal & 0 & 0 & 0 \\ mSB & 6 & Normal & 0 & 0 & 0 \\ mSAH & 3 & Dyspnea & 0 & 1 & 1 & 66.6 \\ \hline \hline \end{tabular}
\end{table}