Fig. 2.
Absolute skin recovery of model biomarkers. Skin recovery of: (a) interleukin (IL)-1α, (b) IL-6, (c) IL-17, and (d) tumour necrosis factor alpha (TNF-α) measured in the skin reservoir model after injection of reference solutions: IL-1α: 0, 233, 700 and 2,100 pg/ml; IL-6: 0, 384, 960 and 2,400 pg/ml; IL-17: 0, 560, 1400 and 3,500 pg/ml; and TNF-α: 0, 561, 1,404 and 3,510 pg/ml. Dialysate concentrations were determined by enzymelinked immunoassay (ELISA). Data are depicted as individual samples (triplicate probes were used for each biomarker concentration injected and every setup was repeated in skin specimens from 3 donors) with mean ± standard deviation. Symbols represent different skin donors (● D4, ▪ D18, ▴ D20). Open symbols indicate values below the lower limit of quantification (LLOQ), and × denotes outliers, which were omitted from statistical analyses. Linear regression lines are depicted together with the corresponding R2 values.