Figure 1.
Physicochemical properties of SiO2 NPs.
Notes: (A) Transmission electron micrographs of SiO2 NPs. (B) Size histogram of SiO2 NPs derived from TEM images. Dispersity (p) is calculated with the formula p = σ/µ, σ = SD; µ = mean value. Primary particle size (dTEM) of SiO2 NPs was calculated as 99.2±2.5 nm (2.5% dispersity). (C) Stability test by analysis of the particle diameter in water (0, 7 days) or culture medium (0, 1, 5, and 7 days). The mean hydrodynamic diameter (dh) from three independent experiments is presented with dispersity (SD). (D) Stability test by leaching analysis. Release of dye molecules from fluorescent SiO2 NPs was determined by fluorescence measurements before and after ultrafiltration through 30 kDa membrane. Fluorescence intensity (%) after 7 days was measured in water and culture medium. (E) Hydrodynamic diameter and zeta potential of SiO2 NPs in water and culture medium (RPMI-1640 supplemented with 10% FBS). dh was determined by calculating the volume distribution.
Abbreviations: NP, nanoparticle; TEM, transmission electron microscopy.