Liposomal ellagic acid enhances the regenerative potential of ADMSC-laden nanofibrous PCL scaffolds in a rat model of spinal cord injury.

Spinal cord injury (SCI) leads to myelin breakdown and extensive neuronal loss around the injury site due to increased oxidative stress. This study aims to develop a comprehensive platform incorporating scaffolds, therapeutic agents, and stem cells to restore structures and pathways in SCI. Scaffolds were created through the electrospinning of a PCL/functionalized multi-walled carbon nanotube (f-MWCNTs) composite, which was then coated with liposomal ellagic acid (EA@lip) and seeded with adipose-derived mesenchymal stem cells (ADMSCs). The optimal drug concentration was determined by conducting MTT and DPPH assays through three different time points. After assessing the biocompatibility and anti-inflammatory properties of the scaffolds for ADMSCs, the implant was tested in a rat model of dorsal hemisection. The female Wistar rats were divided into six groups (n = 10): Sham, SCI, SCI + PCL/f-MWCNTs (PCs), SCI + scaffolds + EA@lip (PC/N), SCI + scaffolds + ADMSCs (PC/C), and SCI + scaffolds + EA@lip + ADMSCs (PC/N/C). In the second week, biochemical analyses were conducted to evaluate oxidative stress in the animals' blood. Throughout the study, the motor function of the animals was monitored. After six weeks, the rats were subjected to real-time PCR and histological analysis, utilizing Cresyl Violet/Luxol Fast Blue staining and evaluating the expression of the genes COX2, GPX1, MBP, and Slc17a6/7. Liposomal encapsulation efficiency was measured to be 33%. The results revealed that EA@lip had the desired size, zeta potential, and lipid concentration. Transmission electron microscopy revealed that f-MWCNTs were well-aligned along nanofibers. EA@lip dramatically enhanced the hydrophilicity of the scaffolds. The MTT assay, DAPI staining, and FE-SEM images confirmed the successful implantation, proliferation, adhesion, and survival of ADMSCs on the liposome-coated scaffold. Additionally, in vitro oxidative stress tests indicated that this platform exhibited superior antioxidant and anti-inflammatory effects for ADMSCs. Histological assessments revealed that the hybrid platform facilitated the regeneration of myelin and neurons, correlating with improved blood levels of oxidative markers. Furthermore, real-time PCR results demonstrated a decrease in COX2 expression and an increase in GPX1, MBP, and Slc17a6/7 expression due to the platform. The findings suggest that the combination of ADMSCs with EA@lip-coated PCL/f-MWCNT scaffolds hold significant promise for applications in spinal cord regeneration.