纳米Ag—SiO2颗粒对小鼠成纤维细胞（L-929）的毒性研究

目的：探讨纳米Ag—SiO2颗粒对小鼠成纤维细胞（L-929）的体外毒性作用。方法：使用透射电镜（TEM）对纳米颗粒进行表征；CCK一8法观察在24h、48h、72h不同浓度纳米颗粒对L-929细胞活性的影响；倒置显微镜观察染毒24h后细胞形态的改变，并检测细胞上清液中乳酸脱氢酶（LDH）漏出率。结果：L-929细胞的生长活性随着纳米Ag—SiO2颗粒浓度的升高和染毒时间的延长而下降，低浓度组（6．25，12．5μg／mL）与对照组无明显差异，倒置显微镜下细胞形态正常，生长良好。而高浓度组（50，100μg／mL）与对照组有明显差异，透射电镜下观察细胞有明显的空泡变性，培养液上清中LDH活性明显升高。结论：纳米Ag—SiO2颗粒的体外细胞毒性呈剂量一时间依赖关系，低浓度组具有良好的生物相容性，高浓度组具有一定的细胞毒性，其毒性可能与细胞膜的完整性遭到破坏有关．

Cytotoxicity of Ag-SiO2 core- shell nanoparticles on L-929 cells.

Objective： To investigate the cytotoxicity of Ag-SiO2 core- shell nanoparticles on L-929 cells in vitro. Method： Ag-SiO2 core- shell nanoparticles were detected by transmission electron microscopy （TEM） ; after L-929 cells were exposured to nanoparticles at different concentrations for 24 h, 48 h, 72 h, the viabilities of L-929 cells were tested by CCK- 8 assay, respectively~ the changes in morphology of L-929 cells were observed under the inverted microscope after the con- tamination, and the leakage rate of LDH in the cell supernatant was tested. Result： With the concentration of the Ag-SiO2 nanoparticles and the exposure time increasing, the survival rate of cells declined. The exposured group of low-concentration nanoparticles showed no significant difference with the control group in the survival rate, and cells of this group observed were in normal morphology and grew well. While the exposured group of high-concentration nanoparticles showed significant difference with the control group, and cells of this group developed obvious vacuolar degeneration. In addition, LDH activity in the supernatant of the culture solution increased substantially. Conclusion： Cytotoxicity of the Ag-SiO2 nanoparticles in vitro showed a dosage-time dependence. The low-concentration group was of good biocompatibility, while the high-concen- tration group showed certain cytotoxicity indicating the integrity of cell membrane might be damaged.