Figure 1
Nanostructured zirconia substrates promote long term β-cell survival. (A) Three-dimensional views of AFM topographic maps of substrates. Representative topographic profiles are superimposed over maps (white lines) in gelatin, flat-ZrO2 and cluster-assembled ns-ZrOx (rms 15 nm). (B) Representative confocal images of human islets grown on different substrates for 5, 10 or 25 days. The cells were triple stained with anti-insulin (red), anti-chromogranin A (green) antibodies or DAPI (blue). The yellow-orange staining indicates colocalization between chromogranin A and insulin. Bar: 20 μm. (C) Quantification of endocrine cells density. Chromogranin A-positive endocrine cells are expressed as percentage of total DAPI-positive cells and are the mean ± SE of five independent experiments, performed in duplicate. The black bar reports the percentage of endocrine cells in freshly isolated islets. Quantification of β-cell density. Insulin-positive β-cells are expressed as percentage of total endocrine cells (chromogranin A-positive cells) and are the mean ± SE of five independent experiments, performed in duplicate. The black bar reports the percentage of β-cells in freshly isolated islets. (*p < 0.05, ns-ZrOx vs gelatin).
