Fig. 4

mir-26a-5p@A-MSN-MG1 delivery system produce long-lasting analgesia duration. A Experimental schematic plot for the establishment of the mouse model of spared nerve injury (SNI). B 50% paw withdraw threshold (PWT) of left hind paw of different treatment groups mice. At the day of 14, 21, 28, 35, 42 and 49, the paw withdrawal thresholds (WTs) of SNI + miR@A-MSN-MG1 group was significantly higher than those of SNI + miR group after single intrathecal injection at the 7th day (*p < 0.05, **p < 0.01, ***p < 0.001 compared with SNI + miR group by Two-way ANOVA followed by Tukey post hoc test, n = 8 in each group). C-E 50% paw withdraw threshold (PWT) of left hind paw of different treatment groups mice at day 12, 14 and 21. F Immunofluorescent study revealed that the enrichment of nanoparticles (Cy5 red) in microglia (IBA1 green) in the L4–5 spinal dorsal horn of SNI mice was significantly increased after MG1 targeting peptide modification but there was no significant change in neurons (MAP2 green). The blue spots are DAPI nuclear staining (Scale bar: 50 μm)