Table 1.

Physicochemical characterization of PS nanoparticles including hydrodynamic diameter and ζ-potential in 10 mM NaCl at 23 °C. Data was collected via DLS and ZetaSizer (n = 3). All values are reported as mean ± standard error (SEM).

Particle Size (nm)	Surface Coating	Mean hydrodynamic diameter ± SEM (nm)	Mean ζ-potential ± SEM (mV)	PDI ± SEM
60	COOH	49.0 ± 2.4	− 23.3 ± 2.3	0.14 ± 0.0
60	PEG	54.3 ± 2.3	− 1.4 ± 0.5	0.20 ± 0.0
100	COOH	110.3 ± 1.6	− 68.8 ± 0.8	0.04 ± 0.0
100	PEG	127.2 ± 1.0	−3.1 ± 0.1	0.02 ± 0.0
200	COOH	216.1 ± 2.4	−56.2 ± 2.0	0.01 ± 0.0
200	PEG	237.0 ± 1.5	−7.6 ± 0.4	0.02 ± 0.0
500	COOH	416.1 ± 6.0	−48.5 ± 1.4	0.05 ± 0.0
500	PEG	545.2 ± 3.6	−4.4 ± 0.1	0.05 ± 0.0
1000	COOH	1167 ± 34	−73.8 ± 2.4	0.44 ± 0.3
1000	PEG	1019 ± 22	—3.4 ± 0.2	0.57 ± 0.3
2000	COOH	1091 ± 106	−47.6 ± 2.2	0.51 ± 0.3
2000	PEG	1271 ± 47	−4.2 ± 0.7	0.43 ± 0.4