The Study On The Effects Of Nanomaterial To Cells In Vitro

Objective To study the effects of silver nanomaterial and rare earth nanomaterial to cells cutured in vitro in order to provide the theoretic and practical foundation for the appli-cation of nanomaterial.Method The proliferation of the cells were investigated by MTT assay and cell-counting method. The nanomaterials were observed by transmission electron microscope (TEM). The expression of IGF- I mRNA was tested by in situ hybridization and dot hy-bridization. Apoptosis of the cells in vitro was detected by TUNEL and TEM.Results (1) In each concentration for silver nanomaterial, there was no significant difference about the inhibiting rate between experimental group and control group. In the final concentrations range 0. 016-0. 500mg/ml for rare-earth nanomaterial, the inhibiting rate of experimental group was lower than that of control group. (2)In various time for sil-ver nanomaterial , there was no significant difference about the number of living cells be-tween experimental group and control group. But for rare-earth nanomaterial, the number of living cells in experimental group was significantly lower than that in control group. (3) The distribution of nanoparticles in the cells was observed using a transmission electron microscope. The silver nanoparticals existed not only out of cells, but also in the cytoplasm. Some silver nanoparticles dented the nucleus. But rare-earth nanoparticals didn't exist in the cytoplasm. (4)In situ hybridization showed that there was hybridization signal of IGF- I mRNA in all groups. (5)Dot hybridization showed that there was no significant difference between the expression of IGF- I mRNA in silver nanomaterial group and that in control group(F=12. 4 ~26. 3,tD = l. 2~1.5,P＞0. 05;F=16. 4 ~31. 2,tD = l. 4~1. 8, P＞0. 05). But the expression of IGF- I mRNA in rare-earth nanomaterial group was lower than that in control group(F=12. 4 ~26. 3,tD = 3. 2 ~ 4. 1,P＞0. 01;F=16. 4~31. 2, tD = 3. 5~4. 6,P＞0. 01). (6)There was no significant difference between apoptosis index of WI-38 cell or Hela cell exposed to silver nanomaterial and that of control group(F=15. 8, tD = 1.8,P＞0. 05;F=17. 2,tD = 2. 1, P＞0. 05). Apoptosis index of WI-38 cell or Hela cell exposed to rare-earth nanomaterial was significantly higher than that of control group (F=15. 8,tD = 4. 3, P＞0. 01;F=17. 2,tD = 4. 6, P＞0. 01). (7)No apoptosis of WI-38 cell and Hela cell exposed to silver nanomaterial was observed by TEM. Some apoptosis cells and necrosis cells of WI-38 cell and Hela cell exposed to rare-earth nanomaterial were observed by TEM .Conclusions CD Silver nanomaterial beyond the antibacterial concentration of silver nanomaterial doesn't affect the activity of WI-38 cell and Hela cell , but rare-earth nanomaterial under the minimum antibacterial concentration of rare-earth nanomaterial can inhibit the activity of WI-38 cell and Hela cell strongly. (2)The silver nanoparticals exist not only out of cells, but also in the cytoplasm. Some silver nanoparticles dent the nucleus. It need research further if silver nanoparticles may exist in the cell for a long time or cause mutation and other diseases. But rare-earth nanoparticals doesn't exist in the cytoplasm. (3)The Expression of IGF- I mRNA can't be induced or inhibited by silver nanomaterial, but it can be inhibited by rare-earth nanomaterial strongly. (4) Apoptosis can not be induced or inhibited by silver nanomateril, but rare-earth nanomaterial can induce apoptosis.