Transplantation of miR-216a-5p-overexpressing mesenchymal stem cells encapsulated in a thermosensitive hydrogel promotes functional recovery in a rat model of spinal cord injury

To evaluate the therapeutic efficacy of mesenchymal stem cells (MSCs) overexpressing miR-216a-5p delivered via a thermosensitive hydrogel in a rat model of spinal cord injury (SCI). A thermosensitive hydrogel was engineered to encapsulate MSCs overexpressing miR-216a-5p (MSC-miR-216a-5p). The hydrogel-cell construct was characterized for its physical properties and transplanted into rats with contusion SCI. Functional recovery was assessed using the Basso, Beattie, and Bresnahan (BBB) locomotor scale, mechanical withdrawal threshold (MWT), and thermal withdrawal latency (TWL). Inflammatory responses were evaluated by measuring pro-inflammatory cytokine levels. The engineered hydrogel demonstrated suitable mechanical properties, temperature-dependent swelling, and controlled degradation behavior. Rats treated with hydrogel-encapsulated MSC-miR-216a-5p showed significantly improved functional recovery, evidenced by higher BBB, MWT, and TWL scores than control groups. The treatment effectively modulated the inflammatory response by reducing pro-inflammatory cytokine levels. Mechanistic studies identified GPBP1 as a direct target of miR-216a-5p, mediating the observed neuroprotective and anti-inflammatory effects. The combination of miR-216a-5p-overexpressing MSCs with a thermosensitive hydrogel delivery system represents a promising therapeutic strategy for SCI treatment. This approach promotes functional recovery and modulates inflammatory responses through GPBP1 targeting, offering potential for clinical translation in SCI therapy.