Fig. 3: PD-L1 bioengineering reverses the hyperglycemia in the NOD mice.

a Schematic illustration of the treatment process. b Ex vivo imaging of main organs revealed that GLP1R-H-NPs could efficiently target the pancreas (6 h post-administration). c Fluorescent imaging of the pancreas from NOD mice i.v. injected with Cy5-labeled PD-L1 analogs on day 7. d Blood glucose levels of the diabetic NOD mice with different treatments as indicated. e Average blood glucose levels of diabetic NOD mice received different treatments. f The occurrence of the NOD mice developed diabetes. Data represent the mean ± s.d. (d–f, n = 12 biologically independent samples for untreated group and PD-L1 group, n = 14 biologically independent samples for the DBCO-PDL-1 group and DBCO/DSPE-PD-L1 group.) g Survival of the mice received different treatments. Data represent the mean ± s.d. (n = 20 biologically independent samples). h, i Representative H&E stained (h) and anti-insulin (red)/anti-glucagon (green) dual stained (i) pancreas sections from NOD mice on day 5 post-treatments. Circles indicate islets in the pancreas. Black arrows indicate the infiltration of immune cells in pancreatic islets. Scale bar: 200 μm. j Representative anti-PD-L1 (red)/anti-glucagon (green) dual stained pancreas sections from NOD mice on day 5 post-treatments. Scale bar: 50 μm. The data were analyzed by one-way two-sided ANOVA; ****P < 0.0001, ***P < 0.001, **P < 0.01, *P < 0.05.