Figure 2: Characterization of liquid-metal nanospheres.

(a) EGaIn was ultrasonically dispersed in ligand containing ethanol mixture (shown schematically in Fig. 1a). (b) The hydrodynamic size of LM-NP/Dox-L measured by dynamic light scattering. Inset: TEM image of LM-NP/Dox-L. Scale bar, 100 nm. (c) The release profiles of LM-NP/Dox-L at different pH levels. (d) Representative TEM images of LM-NP/Dox-L after different time immersed in acidic (pH 5.0) PBS buffer. Scale bars, 100 nm (for 5 min); 100 nm (for 1 h); 100 nm (for 4 h); 400 nm (for 72 h). (e) Polydispersity index (PDI) of LM-NP/Dox-L immersed in neutral (pH 7.4) and acidic (pH 5.0) PBS buffer. (f) Changes of metal ion concentration under neutral and acidic environments. (g) Optical images of LM-NPs before and after acid treatment. Scale bar, 40 μm. (h) Light transmittance change over time. (i) X-ray images (left) of LM-NPs immersed in neutral (pH 7.4) and acidic (pH 5.0) PBS buffer (particles were imaged after 12 h treatment). The images were taken in a 96-well plate. Red lines indicate the areas quantitatively analysed. Grey value analysis (right) of representative area in X-ray images of LM-NPs. Error bars indicated s.d. (n=3).