Z-COTE   Namstm HP1 NIAX
  Coating None None Triethoxycaprylylsilane Dimethoxydiphenylsilane/triehoxycaprylyisilane crosspolymer
Powder# Batch raimber EHDA3001 4051 CNHE0602 FCHE1301
Primary particle size (TEM, nm, # measurements in parenthis Width: 44 ± 2 (260) Diameter: 25 ± 1 (238) Width: 28 ± 2 (201) Width: 36 ± 2 (300)
Length: 73 ± 4 (142) Length: 96 ± 6 (93) Length: 95 ± 5 (94)
Specific surface area (BET, m2/g) 13 ± 2 30 ± 3 14.9 ± 0.5 12 ± 1
In H20# Superoxide radical generation (% negative control) Dark: 800 ± 300* Dark: 280 ± 80 Dark: 220 ± 40 Dark: 170 ± 50
Light: 12,000 ± 3,000* Light: 2,000 ± 400 Light: 4,000 ± 700 Light: 4,000 ± 300
Endotoxin BD BD BD BD
Hydrodynamic particle size (DLS, nm, PDI in parenthesis) 0-time: 410 (0.3) 0-time: 600 (0.6) 0-time: 240 (0.3) 0-time: broad (1)
Zeta potential (mV) 0-time: 27 0-time: 9 0-time: -10 0-time: -7
Altered pH (relative to H2O only) 0-time: -0.1 0-time: 0.0 0-time: -0.1 0-time: -0.1
In complete cell culture medium (HM-5201) Hydrodynamic particle size (DLS, nm, PDI in parenthesis) 0-time: 260 (0.3) 0-time: 25 (0.7) 0-time: 300 (0.6) 0-time: 90 (0.2)
2h: 100 (0.8) 2h: 45 (0.8) 2h: 230 (0.4) 2h: 35 (0.7)
6h: 260 (0.3) 6h: 180 (0.2) 6h: 70 (0.7) 6h: 340 (0.4)
24h: 90 (0.2) 24h: 125 (0.3) 24h: 110 (0.2) 24h: 360 (0.5)
Particle size distribution (DCS, nm) 0-time: 90-500 0-time: ND 0-time: 20-900+ 0-time: 400-900+
Zeta potential (mV) 0-time: 8 0-time: 7 0-time: -10 0-time: -6
2h: -7 2h: -7 2h: -7 2h: -6
6h: -7 6h: -6 6h: -7 6h: -6
24h: -6 24h: -7 24h: -7 24h: -6
Altered pH over 24 h (relative to media only) 0-time: 0.0 0-time: 0.0 0-time: 0.0 0-time: 0.0
2h: 0.0 2h: 0.0 2h: 0.0 2h: -0.2
6h: 0.0 6h: 0.0 6h: 0.0 6h: +0.1
24h: -0.1 24h: 0.0 24h: 0.0 24h: 0.0
*statistically significant compared to negative control (saline only).
The physical and chemical properties of the four types of ZnO nanoparticles were measured as dry powders or as dispersions in either water or cell-culture medium. Polydispersity indices (PDI) are given in parentheses for measurements of hydrodynamic diameters of particles or agglomerates by DLS. BD below detection; ND not detected; #As first reported in Osmond-McLeod et al. [12].
Table 1: Physical and chemical characteristics of the four types of ZnO nanoparticles.