Fig. 4

Human placental perfusion with 0.45 µg/mL DEPs for 6 h. The carbon particle content is determined with femtosecond pulsed laser illumination in maternal and fetal perfusates over time (a). Next, FM ratios are calculated for each time point and compared to FM ratios of the reference compound creatinine (b). Additionally, the carbon particle content is measured in tissue samples of each placenta collected before and after perfusion (c). Data represent the mean (SD) of four independently perfused placentae with medium containing 0.45 µg/mL DEP. p < 0.05 is considered statistically significant (* denotes differences in carbon particle concentration determined in maternal perfusates over time compared to initial amount; ^$ denotes differences in FM ratio between DEP and creatinine, ^# denotes differences in placental carbon particle load before and after DEP perfusion) as analyzed by one-way ANOVA with Tukey’s multiple comparison correction and paired t-test. ANOVA analysis of variance, DEP diesel exhaust particle, FM fetal–maternal, SD standard deviation