Intracellular effects of the T-GNPs. (A.i.) The T-GNPs cluster gamma-tubulin to one pole of the cell. MDA-MB-231 cells treated with IC50 (260 µg/mL) of the T-GNPs for cell viability were stained with anti-γ-tubulin antibodies (for centrosomes; green) and Hoechst 33342 (for DNA; blue). (Aii) Amplification of the clustered centrosomes. The fluorescence intensities corresponding to centrosome staining were quantitated using Image J software. (Bi) Bundling and (Bii) hyper stabilization of cellular microtubules induced by the T-GNPs. The cells treated with 260 µg/mL or 520 µg/mL of the T-GNPs were visualized using anti-α-tubulin antibodies (red) or anti-acetyl-α-tubulin (green) antibodies. (Biii and Biv) Increase in the expression levels of acetyl-α-tubulin in the T-GNPs-treated cells. Western blot showing levels of acetylated tubulin in the presence of the T-GNPs (260 µg/mL and 520 µg/mL). The blots were cropped from different parts of the same blot. The full-length blot at different exposure levels is given in supplementary information. For A.ii. and Biv, the data were statistically significant at ‘**’(P < 0.01) and ‘***’(P < 0.001), when compared to the controls. The results are expressed as mean ± SD; (n = 3). Vin, vinblastine 22.75 µg/mL (25 µM); T, taxol, 42.7 ng/mL (50 nM).