A high-strength nanofiber scaffold loaded with polydopamine-modified magnetoelectric nanoparticles for spinal cord injury

Spinal cord injury (SCI) typically refers to structural damage to the spinal cord tissue caused by various external factors, resulting in permanent functional impairment of sensation and movement below the level of injury. To date, there is still no very effective treatment method in clinical practice. Tissue engineering materials and implants have been extensively studied. This study designed an electrospun nanofiber scaffold with excellent mechanical properties and utilized remote magnetic field stimulation to generate electrical effects for neural function modulation. Initially, polydopamine-modified Fe3O4-BaTiO3 (PDA/Fe-BTi) nanoparticles were constructed and demonstrated to exhibit favorable magnetoelectric effects. Subsequently, comprehensive performance tests were conducted on the prepared nanofibers to determine the optimal concentrations of thermoplastic polyurethane (TPU) and polyethylene oxide (PEO). Using TPU and PEO at these concentrations as the matrix, tannic acid (Ta) was added to enhance mechanical properties, along with the incorporation of PDA/Fe-BTi. Finally, electrospinning technology was employed to prepare the nanofiber scaffold. The co-culture experiment with pheochromocytoma cells (PC12) demonstrated that under the influence of an external magnetic field, the electrospun nanofibers scaffold possess the ability to maintain cellular morphology, exhibit good biocompatibility, and promote axonal growth and development. By implanting the scaffold at the injury site and applying a magnetic field, the microenvironment of the SCI region can be effectively improved, promoting neural regeneration and significantly enhancing the motor function of rats. This study provides novel insights into the application of magnetoelectric composite materials in the field of SCI repair.