Imogolite Synthetized in Presence of As(III) Induces Low Cell Toxicity and Hemolysis, in Vitro, Potential Stabilization of Arsenite Present in Aqueous Systems.

Imogolite is a nanotubular aluminosilicate that has low toxicity in biological systems and due to its morphological and surface properties has a growing interest in environmental applications and biomedical areas. Its synthesis is highly sensitive to the presence of other ions, being able to inhibit or retard the process of imogolite formation, which could change the cytotoxic response of this substrate, something scarcely reported in the literature. In this context, the presence of arsenite during the synthesis of imogolite caused significant changes in the dimensions and surface behavior of these nanotubes. Cell viability was evaluated on EA.hy926 and HepG2 cells by (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) assay at 24 h. Meanwhile, the potential effects on human red blood cells, namely, hemolysis and morphological changes, were determined at 0 and 24 h. The range of % As tested of the nanotube showed cell toxicity similar to the control condition. Similarly, the As-based nanotubes induced hemolysis similar to controls and slight morphological changes of red blood cells at 0 and 24 h of exposition. These results indicate that As-based imogolite-like nanotubes are not toxic nor hemolytic and can be potentially used in processes like water purification.

The [Mo6Cl14]2- Cluster is Biologically Secure and Has Anti-Rotavirus Activity In Vitro.

The molybdenum cluster [Mo6Cl14]2- is a fluorescent component with potential for use in cell labelling and pharmacology. Biological safety and antiviral properties of the cluster are as yet unknown. Here, we show the effect of acute exposition of human cells and red blood cells to the molybdenum cluster and its interaction with proteins and antiviral activity in vitro. We measured cell viability of HepG2 and EA.hy926 cell lines exposed to increasing concentrations of the cluster (0.1 to 250 µM), by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. Hemolysis and morphological alterations of red blood cells, obtained from healthy donors, exposed to the cluster (10 to 200 µM) at 37 °C were analyzed. Furthermore, quenching of tryptophan residues of albumin was performed. Finally, plaque formation by rotavirus SA11 in MA104 cells treated with the cluster (100 to 300 µM) were analyzed. We found that all doses of the cluster showed similar cell viability, hemolysis, and morphology values, compared to control. Quenching of tryptophan residues of albumin suggests a protein-cluster complex formation. Finally, the cluster showed antiviral activity at 300 µM. These results indicate that the cluster [Mo6Cl14]2- could be intravenously administered in animals at therapeutic doses for further in vivo studies and might be studied as an antiviral agent.

The cluster [Re6Se8I6]3- induces low hemolysis of human erythrocytes in vitro: protective effect of albumin.

The cluster Re6Se8I63- has been shown to induce preferential cell death of a hepatic carcinoma cell line, thus becoming a promising anti-cancer drug. Whether this cluster induces acute hemolysis or if it interacts with albumin remains unclear. The effect of acute exposure of human red blood cells to different concentrations of the cluster with and without albumin is described. Red blood cells from healthy donors were isolated, diluted at 1% hematocrit and exposed to the cluster (25-150 µM) at 37 °C, under agitation. Hemolysis and morphology were analyzed at 1 and 24 h. The potential protection of 0.1% albumin was also evaluated. Exposition to therapeutic doses of the cluster did not induce acute hemolysis. Similar results were observed following 24 h of exposition, and albumin slightly reduced hemolysis levels. Furthermore, the cluster induced alteration in the morphology of red blood cells, and this was prevented by albumin. Together, these results indicate that the cluster Re6Se8I63- is not a hemolytic component and induces moderate morphological alterations of red blood cells at high doses, which are prevented by co-incubation with albumin. In conclusion, the cluster Re6Se8I63- could be intravenously administered in animals at therapeutic doses for in vivo studies.