Fig. 1: Viability and transplantation of isolated islets and MVF.

a Bright-field microscopic image of an isolated neutral red-stained islet. Scale bar: 50 μm. b Fluorescence microscopic image of insulin (red)- and CD31 (green)-stained islet. Cell nuclei are stained with Hoechst 33342 (blue). Scale bar: 50 μm. c Bright-field microscopic image of an isolated MVF. Scale bar: 15 µm. d Fluorescence microscopic image of an α-SMA (red)- and CD31 (green)-stained MVF. Cell nuclei are stained with Hoechst 33342 (blue). Scale bar: 15 μm. e Fluorescence microscopic image of a PI (red)-stained islet. Cell nuclei are stained with Hoechst 33342 (blue). Scale bar: 100 μm. f Quantitative analysis of PI-positive cells (% of all Hoechst 33342-positive cells) within islets directly after their isolation. H₂O₂-treated islets served as a positive control. Mean ± SEM (n = 20 each group). An unpaired Student’s t test was used. ^*P < 0.05 vs. islets. g Fluorescence microscopic image of a PI (red)-stained MVF. Cell nuclei are stained with Hoechst 33342 (blue). Scale bar: 15 μm. h Quantitative analysis of PI-positive cells (% of all Hoechst 33342-positive cells) within MVF directly after their isolation. H₂O₂-treated MVF served as a positive control. Mean ± SEM (n = 20 each group). An unpaired Student’s t test was used. ^*P < 0.05 vs^. MVF. i Schematic illustration of the co-transplantation of islets and MVF. The isolated islets and MVF were mixed, centrifuged, resuspended in physiological saline solution and transplanted (Tx) under the kidney capsule or into the subcutaneous space of diabetic mice by means of an Hamilton syringe.