title: Comparative cytotoxicity evaluation of lanthanide nanomaterials on mouse and human cell lines with metabolic and DNA-quantification assays.
abstract: Lanthanide nanomaterials are considered a less toxic alternative to quantum dots for bioimaging applications. This study evaluated the cytotoxicity of terbium (Tb)-doped gadolinium oxide (Gd(2)O(3)) and dysprosium oxide (Dy(2)O(3)) nanoparticles exposed to human (BEAS-2B) and mouse (L929) cell lines at a concentration range of 200-2000 μg/ml for 48 h. Two assay methods were utilized-WST-8 assay (colorimetric) based on mitochondrial metabolic activity and Pico-Green assay (fluorescence), which measures total DNA content. The authors' data showed that Tb-doped Gd(2)O(3) nanoparticles were consistently more toxic than Tb-doped Dy(2)O(3) nanoparticles. However, exposure to these nanomaterials caused a decrease in proliferation rate for both cell lines rather than a net loss of viable cells after 48 h of exposure. Additionally, there was some degree of discrepancy observed with the two assay methods. For the mouse L929 cell line, the WST-8 assay yielded consistently lower proliferation rates compared to the Pico-Green assay, whereas the opposite trend was observed for the human BEAS-2B cell line. This could arise because of the differential effects of these nanoparticles on the metabolism of L929 and BEAS-2B cells, which in turn may translate to differences in their postexposure proliferation rates. Hence, the Pico-Green assay could have an advantage over the WST-8 assay because it is not skewed by the differential effects of nanomaterials on cellular metabolism.
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, Block N4.1, 50 Nanyang Avenue, Singapore 639798, Singapore.
authors.forename: Boon Chin
authors.initials: BC
authors.lastname: Heng
authors.forename: Gautom Kumar
authors.initials: GK
authors.lastname: Das
authors.forename: Xinxin
authors.initials: X
authors.lastname: Zhao
authors.forename: Lwin-Lwin
authors.initials: LL
authors.lastname: Ma
authors.forename: Timothy Thatt-Yang
authors.initials: TT
authors.lastname: Tan
authors.forename: Kee Woei
authors.initials: KW
authors.lastname: Ng
authors.forename: Joachim Say-Chye
authors.initials: JS
authors.lastname: Loo
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004247:DNA / Q000032:analysis; D006801:Humans; D028581:Lanthanoid Series Elements / Q000633:toxicity*; D051379:Mice; D049329:Nanostructures / Q000633:toxicity*; D013778:Tetrazolium Salts / Q000378:metabolism
chemical_list: C476329:2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H tetrazolium monosodium salt; D028581:Lanthanoid Series Elements; D013778:Tetrazolium Salts; D004247:DNA