*2.10. WST Assay*

10<sup>4</sup> 1301 cells were cultivated in total volume 100 μL in flat-bottomed 96-well cell culture plates (TPP, Switzerland) for 72 h in the presence of blank chemodrug-loaded dendrimersomes as well as free drugs. Non-treated cells were cultivated in parallel as a control.

After cultivation, 10 μL of the WST-1 reagent (Takara Bio Inc, Kusatsu, Japan) per well was added, and the plates were incubated for 4 h. To evaluate the cell viability, optical absorbance at 450 nm was directly read against the background control, the reference was read at 620 nm (TriStar LB 941 Multimode Microplate Reader, Berthold Technologies GmbH&Co., Bad Wildbad, Germany). Cell viability was calculated as a ratio of absorbance of treated cells samples to that of non-treated control, then converted into percentage. Cell viability values were plotted against lgC, fitted with Boltzmann sigmoidal curve (r<sup>2</sup> <sup>&</sup>gt; 0.95), and the <sup>−</sup>lg(IC50) values were estimated from the fitting data.
