Daphedar Azharuddin, Taranath Tarikere C
Environmental Biology Laboratory, P. G. Department of Studies in Botany, Karnatak University, Dharwad 580003, Karnataka, India.
Toxicol Rep. 2018 Aug 31;5:910-918. doi: 10.1016/j.toxrep.2018.08.018. eCollection 2018.
Noble metal nanoparticles afford a tool for investigation and its application in biological systems has had the greatest impact in biology and biomedicine. The present work reports an ecofriendly approach for the synthesis of silver nanoparticles (AgNPs) using an aqueous leaf extract of The silver nanoparticles were characterized by using following instruments viz. UV-vis spectrophotometer, FTIR, XRD AFM and HR-TEM. The UV-vis spectrum showed a characteristic absorption peak at 404 nm. FTIR data reveals the possible involvement of various functional groups for reduction and biocapping of AgNPs. XRD data confirmed the crystalline nature of silver nanoparticles. Morphology, size and distribution of the AgNPs were determined by using AFM and HR-TEM. The average size of AgNPs ranges between 10 and 25 nm and are spherical in shape. The silver nanoparticles were evaluated for their cytotoxic effect on mitotic chromosomes of root meristematic cells of using different concentrations viz. 4, 8, 12 and 16 μg/ml at the time interval of 6, 12, 18 and 24 h. It is evident from the results that the higher concentration of AgNPs found to inhibit mitotic index and caused chromosomal abnormalities such as chromosomal bridge, sticky chromosomes, laggard anaphase, diagonal anaphase, c-metaphase and chromosomal breaks. Therefore, it can be concluded that higher concentrations of silver nanoparticles may induce significant inhibition of root meristem activity and causing DNA damage.
贵金属纳米颗粒为研究提供了一种工具，其在生物系统中的应用对生物学和生物医学产生了最大的影响。本工作报道了一种使用 的水叶提取物合成银纳米颗粒（AgNPs）的环保方法。使用以下仪器对银纳米颗粒进行了表征，即紫外可见分光光度计、傅里叶变换红外光谱仪、X射线衍射仪、原子力显微镜和高分辨率透射电子显微镜。紫外可见光谱在404nm处显示出特征吸收峰。傅里叶变换红外光谱数据揭示了各种官能团可能参与了AgNPs的还原和生物封端。X射线衍射数据证实了银纳米颗粒的晶体性质。通过原子力显微镜和高分辨率透射电子显微镜确定了AgNPs的形态、尺寸和分布。AgNPs的平均尺寸在10至25nm之间，呈球形。使用不同浓度（即4、8、12和16μg/ml）在6、12、18和24小时的时间间隔内评估了银纳米颗粒对 根分生组织细胞有丝分裂染色体的细胞毒性作用。结果表明，较高浓度的AgNPs可抑制有丝分裂指数并导致染色体异常，如染色体桥、粘连染色体、落后后期、对角后期、c中期和染色体断裂。因此，可以得出结论，较高浓度的银纳米颗粒可能会显著抑制根分生组织活性并导致DNA损伤。
