Figure 3. Heatmap to compare the toxicity of various PEI-coated particles in undifferentiated and differentiated NHBE by a rapid throughput multi-parametric assay.
The heatmap was established using SSMD statistical analysis to evaluate significant differences in the toxicological response profiles of undifferentiated and differentiated NHBE. The response parameters included in the multi-parametric assay includes measurement of intracellular calcium flux (Fluo-4), superoxide generation (MitoSox Red), H2O2 generation (DCF) and mitochondrial membrane depolarization (JC-1). Cells were treated by MSNP-PEI or MSNP at doses of 0.4, 0.8, 1.6, 3.2, 6.3, 12.5, 25, 50, 100, 200 μg/mL. Epifluorescence images were collected hourly for 6 hr. The layout of the 384 well plate used in this experimentation is shown in Fig. S7. Full details of the multi-parametric assay, preparation of the particles and processing of the plate appear in materials and methods. The fluorescent dyes are displayed in Table 3.