Effect of crowding on hIAPP cytotoxicity and on cell membrane enhanced hIAPP aggregation.

<p><b>A</b> Cell viability of pancreatic β-cells after exposure to hIAPP (10 µM) in crowded environments of different type (Ficoll, dextran, BSA) and concentration (10 and 20% (w/v)). As controls, viability of β-cells incubated without hIAPP and crowder reagents (grey bar) as well as with hIAPP (10 µM) without crowding reagents (black bar) are shown. <b>B</b> Time dependent ThT fluorescence spectroscopy assay of 10 µM hIAPP in a solution containing 0.5 mg/mL cell membrane vesicles (lipids extracted from the pancreatic β-cell line INS-1E) and 10 to 40% Ficoll as crowding reagent. The upper panel shows absolute ThT fluorescence intensities; whereas the corresponding normalized data are presented in the lower panel. Both data sets show mean values (errors bars indicate standard deviations) of ≥6 experiments.