Fig. 2

Cy5.5AuNPs do not elicit cytotoxicity in primary neuronal cultures. a Four representative plates of a 96 wells-plate containing 200 μl of Cy5.5-AuNPs at four different concentrations that range from 1 to 0.001 mg/ml. Images were acquired using the 675/720 filters and averaged radiant efficiencies were measured using a circular ROI superimposed on each well. Histogram of b shows the linearity between the radiant efficiency and AuNPs concentration. c Percentages (± S.D.) of dying hippocampal neurons in cultures treated with AuNPs. Percentages (± S.D.) of dying cells, scored with Sytox, are shown on c. Inset shows a representative picture derived from cultures receiving AuNPs for 24 h, n = 4 independent cultures. d Au-NPs distribution in hippocampal cultures receiving 0.1 mg/ml of Cy5.5-NPs for 24 h. Cultures were labelled for GFAP to identify astrocytes (upper row d) and NeuN to identify neurons (lower row d). Scale bar 15 µm for c and 40 µM for d