The effect of PU/MWCNT nanofiber scaffolds containing hesperidin nanoparticles and mesenchymal stem cells on the microglia and astrocyte phenotype in the spinal cord injury model.

Spinal cord injury (SCI) is a neurodegenerative disease involving inflammation, microgliosis, and astrocytosis. This study examined how polyurethane/multi-walled carbon nanotube (PU/MWCNT) nanofiber scaffolds containing hesperidin nanoparticles (NPs) and adipose-derived mesenchymal stem cells (AMSCs) affect the phenotype of microglia and astrocytes in an SCI model. Thirty-six male rats were divided into six groups: SCI, sham, scaffold, scaffold with AMSCs, scaffold with NPs, and scaffold with AMSCs and NPs. Motor performance in the hind limbs was evaluated using the Basso, Beattie, and Bresnahan (BBB) behavioral test. Tissue sections were prepared and stained with Luxol Fast Blue (LFB) to examine the white matter; Nissl staining was performed to examine neurons. The populations of microglia and astrocytes were assessed using immunofluorescence with Iba-1 and GFAP antibodies, respectively. The expression levels of the A1 (pro-inflammatory) astrocyte gene (C3), the M1 (pro-inflammatory) microglia gene (iNOS), and inflammatory factors, such as IL-1β and TNF-α, were assessed using qRT-PCR. All data were analyzed using SPSS and GraphPad Prism software. Functional evaluation revealed significant behavioral improvement in the group containing a scaffold, AMSCs, and NPs. Nissl and LFB images revealed increased numbers of neurons and remyelination areas in this group, accompanied by downregulation of the IL-1β and TNF-α genes. The M1 and A1 phenotypes significantly decreased in this group. Ultimately, PU/MWCNT nanofiber scaffolds containing hesperidin nanoparticles and AMSCs reduced M1 microglia and A1 astrocytes, as well as inflammatory factors, while increasing neurons and remyelination in the SCI model.