Evaluation of Viability and Proliferation Profiles on Macrophages Treated with Silica Nanoparticles In Vitro via Plate-Based, Flow Cytometry, and Coulter Counter Assays
Table 2
Summary of LAL-base kits used, controls, and results.
SiO2 NP dilutions
Kit name
Endotoxin sensitivity
E. coli O55:B55 standards
Positive controls
Negative controls
Results
Comments
1 g/L; 0.1 g/L; 0.01 g/L; 0.001 g/L
LAL QCL-1000
A405 nm is linear between 1 EU/mL and 0.1 EU/mL
From1 EU/mL to 0.015 EU/mL
SiO2 NP dilutions spiked with E. coli endotoxin O55:B55 (0.5 EU/mL)
LAL-free water and PBS
SiO2 NPs are endotoxin-free
colorimetric method; SiO2 NP diluted in PBS (pH = 6–8)
1 g/L; 0.1 g/L; 0.01 g/L; 0.001 g/L
PYROGENT Plus
0.125 EU/mL
From1 EU/mL to 0.015 EU/mL
SiO2 NP dilutions spiked with E. coli endotoxin O55:B55 (0.5 EU/mL)
LAL-free water and PBS
SiO2 NPs are endotoxin-free
gel clot method; SiO2 NP diluted in PBS (pH = 6–8)
1 g/L; 0.1 g/L; 0.01 g/L; 0.001 g/L
Pyrosate
0.25 EU/mL
N/A
SiO2 NP dilutions spiked with endotoxin (provided by vendor)
LAL-free water
SiO2 NPs are endotoxin-free
gel clot method; SiO2 NP diluted in water (pH = 10.25)