FIGURE 3.
Nanoparticle zeta potential and ionic strength. PLGA nanoparticles were produced empty (Blank) or with recombinant proteins both with and without plx. The nanoparticles were dispersed in different buffer solutions to obtain a 0.05% (w/v) solution. The zeta potential was measured using laser Doppler electrophoresis (Zetasizer Nano ZS90). To determine the effect of dispersion buffer ionic strength on the zeta potential of nanoparticles, the nanoparticles were dispersed in dilutions of PBS at pH 7.0 (ionic strengths: 1.5 × 10−1 m, 1.5 × 10−2 m, 8.5 × 10−3 m, 1.5 × 10−3 m, 1.5 × 10−4 m, and 1.5 × 10−5 m). The zeta potentials were measured in triplicate for three different preparations of nanoparticles for each condition, and each point presents the mean ± S.D.