Fig. 3
The effect of exposure to PS-NPs with different charges on glucose tolerance (OGTT), insulin tolerance (ITT) and insulin resistance. (A) Differences in blood glucose levels over time, after the administration of 2 g/kg glucose; (B) Blood glucose area of OGTT under the curve (AUC); (C) Differences in blood glucose levels over time after the administration of 0.75 U/kg insulin injection; (D) Blood glucose area of ITT under the curve (AUC); (E) Serum insulin level; (F) HOMA-IR level. Saline, NPs-C, NPs, NPs-N, STZ, STZ -SC, STZ - NPs-C, STZ - NPs-C-SC, STZ - NPs, STZ - NPs -SC, STZ - NPs-N, and STZ-NPs-N-SC represent Saline group, NPs-COOH group, NPs group, NPs-NH2 group, Fat-STZ-Saline group, Fat-STZ-Saline-SC79 group, Fat-STZ-NP-COOH group, Fat-STZ-NP-COOH-SC79 group, Fat-STZ-NPs group, Fat-STZ-NPs-SC79 group, Fat-STZ-NPs-NH2 group and Fat-STZ-NPs-NH2-SC79 group, respectively. Results are presented as the mean ± SEM, n = 5–10. AUC was calculated by Area Under the Curve. Statistical significance was analyzed by One-Way ANOVA among multiple groups. * means p < 0.05, ** means p < 0.01, *** means p < 0.001 compared with the saline-vehicle control group; & means p < 0.05, && p < 0.01 compared with Fat-STZ diabetic group; # means p < 0.05, ## means p < 0.01, ### means p < 0.001 compared with the Fat-STZ-NPs/NH2/COOH-SC79; $ means p < 0.05, $$ means p < 0.01, $$$ means p < 0.001 compared between exposure groups; ns means no significant difference