Fig. 5: HMPS@AcDX microspheres improve motor function and reduce spinal cord edema.

a Microspheres were intrathecally injected within 5 min after weight drop at T10 level. b–d MPS concentration in cerebral spinal fluid (CSF) as a function of time (b), and the corresponding area under curve (AUC; c) and mean residence time (MRT; d). n = 5 rats per time point; every rat was only sampled once. e Rats were functionally graded up to 28 days post-injury by BBB grading scale (n = 10, 7, 8, and 9 for SCI/MPS/LAcDX, HAcDX, LMPS@AcDX and HMPS@AcDX, respectively. Data are presented as mean values ± SD for (b–e). f Sagittal spinal cord sections stained with Nissl display the injury area of spinal cord at day-28 post trauma. g Comparison of the lesion volume after treatment (n = 5 per group). h Sagittal and axial spinal cord T2 weighted images at day-28 after injury. (1) & (1′) are axial images in injury epicenter, (2) & (2′) are axial images in far-injury area, (1′) & (2′) are axial color maps transformed from (1) and (2) normal axial images and the blue color represents the edema signal. i Intensity ratio for the signal of lesion to normal spinal cord and cord volume determined for consecutive slices at day-1 and day-28 post injury (n = 5 per group). j TUNEL-positive apoptotic cells (in green) in sagittal spinal cord sections at day-1 post trauma. The nuclei of all cells were stained with DAPI (in blue). k Comparison of the number of TUNEL-positive cells after treatment (n = 6 per group). Box plots show the minimum value, the first quartile, the median, the third quartile, and the maximum value. The intervention groups were compared with SCI group (*); HMPS@AcDX group was compared with LMPS@AcDX group (^#) and LAcDX group (^⊥); *, ^⊥P < 0.05, **, ^##P < 0.01, ***, ^###, ^⊥⊥⊥P < 0.001. Statistical significance was analyzed using one-way ANOVA followed by Fisher’s post-hoc test. Exact P values are given in the Source data file.