Assessment of Charged AuNPs: From Synthesis to Innate Immune Recognition

Figure 3

(a) Size distribution by intensity of AuNP polymer (50 μg/mL) from DLS measurements after incubation in human serum (HS) at a ratio of 1 : 1 for 15 mins at 37°C; the results demonstrate that the PEGylated PLL-AuNP size was the least affected by serum protein adsorption (13 nm increase only), while the non-PEGylated PLL-AuNPs increased enormously (more than 150 nm), indicating a strong interaction with plasma protein; PVA-AuNPs were also shown to increase by about 80 nm. (b) Zeta potential measurements on the corresponding AuNP polymers show that the charge of PVA-AuNPs and PLL-PEG-AuNPs witnessed a very slight change in comparison to non-PEGylated PLL-AuNPs that was found to decrease from +33.8 ± 2.5 to +3 ± 0.2 mV. (c) 1-D gel electrophoresis of differently charged AuNPs after incubation with human serum. A 12% SDS gel was used to visualize the difference in serum protein adsorption on charged nanoparticles. Plasma proteins at 0.1% and 1% were used for comparison. Given that human serum was undiluted during incubation, the amount of plasma serum proteins adhered to the polymer-coated nanoparticles is relatively low compared to 0.1% plasma proteins alone.

(a)

(b)

(c)