Fig. 2

Locally delivered labeled USC-Exo home to the injured spinal cord site and promote locomotor and sensory function recovery. a Schematic representation of the procedure used to administer labeled USC-Exo. b In vivo imaging of animals that received a local intrathecal injection with/without DiR-labeled USC-Exo embedded in hydrogels in mice. c Immunofluorescence staining of the T10 spinal segment area in the sham (upper panel) and injured (lower panel) mice. CD31 (green), PKH26-Exo (red), nuclei (blue). Scale bar = 10 μm. d Quantitative PKH26-Exo mean signal intensity in the endothelial cells of the T10 spinal segment in sham and injured mice. e Distribution of the BMS scores per group throughout the 56-day period. f Distribution of sensory recovery per group at 0, 7, 14, 21, 28, and 56 days post-USC-Exo treatment. g Representative transverse HE stained sections 56 days post-SCI at distances 200 μm caudal to the injury epicenter. Scale bar = 1 mm. h Graphical representation showing the quantitative data comparing lesion cavities among different treatment groups. i Representative electrophysiological traces per group at 56 days post-SCI. j Quantification of the amplitude and latent period of MEPs in the USC-Exo-treated, PBS-treated, and sham mice. Two-way ANOVA with Tukey’s multiple comparisons. The data are presented as the means ± SD; n = 6 per group. *p < 0.05, **p < 0.01 compared with different treatment groups