Agglomeration, sedimentation, and cellular toxicity of alumina nanoparticles in cell culture medium

Metal oxide nanoparticles with low toxicity

“…Low toxicities of In 2 O 3 , Al 2 O 3 , and SnO 2 materials are in agreement with the data reported in other studies. Although there have been studies reporting effects of a-alumina on reduction of embryo growth and hatchability in freshwater snails [10] and the inhibition of the growth of algae [13], the majority of the studies on the toxicity of alumina indicate that it has moderate [18] to low toxicity [12,14,16,17,20], as documented in studies on yeast [12], different cell cultures [14,20], plants [16], E. coli bacteria [17], and oxidative stress in human blood serum [19]. Exceptions can possibly occur in case of inhalation where inflammatory response can occur [11], which is also the case for In 2 O 3 and indium tin oxide nanoparticles (with indium oxide less toxic compared to indium tin oxide) [15].…”

“…We have selected to study the following metal oxides: a-Al 2 O 3 , In 2 O 3 , and SnO 2 , which have not been extensively studied but are expected to result in low to moderate toxicity [10][11][12][13][14][15][16][17][18][19][20]. The majority of studies was performed on alumina which exhibited low to moderate toxicity according to literature reports [12,14,[16][17][18]20], while there have been very few studies on tin oxide [18] and indium oxide [15]. On the other hand, anatase TiO 2 is well studied and known to exhibit toxicity to various organisms under different illumination conditions [9].…”

High content analysis at single cell level identifies different cellular responses dependent on nanomaterial concentrations

“…Various explanations have been suggested for this phenomenon, including, differences between cell types 12 , incubation conditions (NM concentration, time, type of culture medium) 12 13 , material properties (colloidal stability, charge, size, etc.) 14 15 and the type of toxicity assays performed 15 . Other factors that can contribute to this variability are the lack of adequate NM characterization and/or interference of NMs with common toxicity assays 15 16 .…”

Intrinsic and Extrinsic Properties Affecting Innate Immune Responses to Nanoparticles: The Case of Cerium Oxide

“…Comparing studies regarding nanomedicine and nanosafety, it seems that often the differently observed biological effects of NPs are related not only to its parental composition and purity but also to its final aggregation state ( 40 ), which is independent of the employed material and can be reproduced with other NPs. For instance, aggregates of TiO 2 ( 41 ), Al 2 O 3 ( 42 ), and Fe 2 O 3 ( 43 ) NPs show similar toxicity to CeO 2 aggregates ( 37 , 44 ), as well as CeO 2 ( 45 ) or Au NPs ( 46 ) carrying cationic amphipathic molecules on their surfaces have been observed to be similarly toxic. Regarding aggregates, in the case of CeO 2 , Rogers et al ( 44 ) evaluate how exposure to different concentrations of aggregated CeO 2 NPs affects indices of whole animal stress and survivability in Caenorhabditis elegans .…”