Electrospun PLGA Scaffolds Co-loaded With Neural Stem Cells And Fingolimod For Repairing Spinal Cord Injury

Background: How to improve the therapeutic effect of spinal cord injury has high clinical value due to its complicated mechanism.Fingolimod(FTY720)is a drug used in the treatment of multiple sclerosis.PLGA has a wide application in tissue engineering because of its good properties in histocompatibility.In the early stage of this study,the process conditions of electrostatic spinning technology were explored,and PLGA nanofiber scaffolds containing FTY720 were prepared by electrostatic spinning technology.The results showed that FTY720/PLGA scaffolds with different mass ratios affected the fiber diameter and hydrophilicity.In addition,some studies have shown that neural stem cell(NSC)has an important effect in spinal cord injury repair.Therefore,this study attempts to fabricate FTY720/PLGA electrospun scaffold loaded with NSC to explore and prove that FTY720/PLGA scaffolds loaded with NSC could promote the recovery in spinal cord injury and has original scientific significance.Objective: A electrospun PLGA scaffolds with FTY720 was fabricated and fiber diameter and water contact angle was measured.The effects of electrospun PLGA/FTY720 scaffolds with different mass ratio on NSC proliferation and differentiation were evaluated.The treatment effect of the combination of PLGA/FTY720 scaffolds loaded with neural stem cells was measured by situ transplantation on a rat model of spinal transection.Methods: FTY720 and PLGA were mixed in different mass ratio and electrospun PLGA/FTY720 films were manufactured using electrostatic spinning technology.NSC were cultured on different electrospun PLGA/FTY720 films.CCK-8 method was used to evaluate the proliferation of NSC on different films.The influence of FTY720 on NSC differentiation was measured by immunofluorescence and RT-PCR.Then a rat model of spinal transection was established to investigate the effects of PLGA/FTY720 scaffolds loaded with NSC.Functional recovery results were performed by BBB score.Immunofluorescence staining and HE staining were used to analyze the number of newborn neurons and the regeneration effects.Results: The results showed that the PLGA/FTY720 scaffolds prepared by electrostatic spinning technology have suitable fiber diameter and good hydrophilicity.PLGA/FTY720 scaffolds could promote the proliferation of neural stem cells.For NSC differentiation,medium and high mass ratio of FTY720 could effectively promote the differentiation of NSC into oligodendrocytes and significantly inhibit the differentiation of NSC into astrocytes.Animal experiments results showed that the PLGA/FTY720 scaffolds loaded with NSC had better recovery effect in spinal cord injury treatment.Conclusion: The electrospun PLGA/FTY720 scaffolds had good biological properties.Electrospun PLGA/FTY720 scaffolds loaded with NSC can effectively restore the motor function of spinal cord injury rats,promote the newborn neurons and inhibit the generation of astrocytes.The combined application of NSC and FTY720 biological scaffold may have potential applications for spinal cord injury as a nerve implant.