Polydopamine Nanoparticle-encapsulated Psoralen Promotes Motor Function Recovery from Spinal Cord Compression Through Regulating Phosphatidylinositol 3-kinase/Protein Kinase B Signaling Through miR-140-5p

Background: Psoralen is a biomaterial that promotes bone growth and repair and has been widely used in clinical orthopedic surgeries. Objectives: This study aims to explore the role and mechanism of polydopamine nanoparticle-encapsulated psoralen (PSO/PDA NPs) in the recovery of motor function after spinal cord compression. Materials and Methods: A Compressive Spinal Cord Injury (CSCI) rat model was constructed to explore the effects of PDA NPs and PSO/PDA NPs on spinal cord compression, and how PSO/PDA NPs regulate miR-140-5p, improve motor function of spinal cord compression, and 740 Y-P and LY294002 were used to explore the mechanism of PI3K/Akt signaling in PSO/PDA NPs to promote the recovery of motor function of spinal cord compression. Further experiments were conducted on CSCI rats to verify its mechanism through the combined intervention of miR-140-5p inhibitor and 740 Y-P. Results: PSO/PDA NPs have a good effect in the rehabilitation after spinal cord compression, and can inhibit miR-140-5p expression, upregulate PI3K/Akt signal, inhibit the apoptosis rate of neurons in CSCI rats, and inhibit the expression of platelet activating factor (PAF), promote Bcl-2 expression, thereby reducing Bax expression. Conclusion: PSO/PDA NPs downregulate miR-140-5p and promote PI3K/Akt pathway, thereby accelerating the recovery of related functions after spinal cord compression, laying the foundation for the development of drugs targeting CSCI.