Table 1 Physical and chemical properties of the four types of ZnO nanoparticles

Powder

Coating

None

None

Triethoxycaprylylsilane

Dimethoxydiphenylsilane/Triethoxycaprylylsilane crosspolymer

N/A

Batch number

EHDA3001

4051

CNHE0602

FCHE1301

N/A

TEM mean primary size (nm)

Width⁺: 44 ± 12

Diameter: 25 ± 1

Width: 28 ± 2

Width: 36 ± 2

N/A

Length: 73 ± 3

Length: 96 ± 6

Length: 95 ± 6

BET total surface area (m ² /g) (#1)

14.5

32.5

14.4

10.8

N/A

BET total surface area (m ² /g) (#2)

12.3

28.2

15.4

12.7

In H ₂ O

Generation of peroxynitrile or

Dark: 800 ± 300*

Dark: 280 ± 80

Dark: 220 ± 40

Dark: 170 ± 50

N/A

superoxide radicals (% negative control)

Light: 12,000 ± 3000*

Light: 2000 ± 400

Light: 4000 ± 700

Light: 4,000 ± 300

Endotoxin

BD

BD

BD

BD

N/A

DLS average particle size (nm) (PDI in parenthesis)

0-time: 410 (0.34)

0-time: 600 (0.56)

0-time: 240 (0.25)

0-time: broad (0.96)

0-time: N/A

Zeta potential (mV)

0-time: 27

0-time: 9

0-time: -10

0-time: -7

0-time: -3

Altered pH (relative to H ₂ O only)

0-time: -0.1

0-time: 0.0

0-time: -0.1

0-time: -0.1

0-time: N/A

In cell culture medium (DMEM:F12, 1:1)

DLS average particle size (nm) over

0-time: 500 (0.54)

0-time: 240 (0.31)

0-time: 360 (0.36)

0-time: 150 (0.21)

0-time: 20 (0.39)

24 h (PDI in parenthesis)

2 h: 300 (0.47)

2 h: 350 (0.36)

2 h: 120 (0.17)

2 h: 150 (0.21)

2 h: 20 (0.42)

6 h: 400 (0.49)

6 h: 600 (0.57)

6 h: 100 (0.15)

6 h: 150 (0.21)

6 h: 20 (0.40)

24 h: 360 (0.36)

24 h: 440 (0.44)

24 h: 260 (0.28)

24 h: 203 (0.25)

24 h: 10 (0.39)

DCS particle size distribution (nm)

0-time: 100-900+

0-time: BD

0-time: 150-900+

0-time: 100-400

0-time: BD

Zeta potential over 24 h (mV)

0-time: -9

0-time: -8

0-time: -10

0-time: -7

0-time: -6

2 h: -8

2 h: -8

2 h: -8

2 h: -4

2 h: -6

6 h: -10

6 h: -8

6 h: -5

6 h: -6

6 h: -6

24 h: -13

24 h: -9

24 h: -6

24 h: -8

24 h: -6

Altered pH of media over 24 h (relative to media only)

0-time: +0.1

0-time: -0.1

0-time: +0.1

0-time: +0.2

N/A

2 h: +0.2

2 h: 0.0

2 h: +0.1

2 h: -0.2

6 h: -0.1

6 h: +0.1

6 h: -0.1

6 h: 0.0

24 h: -0.2

24 h: 0.0

24 h: 0.0

24 h: 0.0