Fabrication Of A Novel Electrospun Aligned Nanofibrous Scaffold For Dural Engineering And Application

Background Spinal surgery leads to a higher incidence of dural injury in the clinic.Improper handling may lead to a series of adverse sequelae,such as continuous leakage of cerebrospinal fluid through the incision,brain abscess,meningitis,intracranial hemorrhage,hematoma and neurological dysfunction.The dura mater spinal is non-renewable,and the body usually fills the dural defect with scar healing.At present,clinically,there is no dural substitute material whose structure and function are similar to that of the natural dura mater,which also leads to clinical problems such as long treatment cycles for dural defects,complications,and low cure rates.In order to realize the natural healing of the dural high-quality and less scar,there is an urgent need for a dural restoration material that is similar to a natural dural membrane structure and can guide dural collagen fibers to grow in accordance with a dura mater collagen fiber arrangement.In this study,goats were used as the research object,and the bioengineered material polylactic acid-glycolic acid copolymer(PLGA)with the advantages of easy accessibility,good biocompatibility,and degradable controllability was used as the raw material of the dura mater,using electrospinning nanofiber scaffold preparation technology which is similar to the natural dural space structure.We observed whether the structure and mechanical properties of the scaffolds were close to natural goat dura mater,and verified their biocompatibility after implantation on the scaffold surface cells,and then replanted in goat to explore the feasibility of repairing dural defects with nanofiber scaffolds.Objective A PLGA nanofiber scaffold similar to that of goat spinal membrane was constructed to explore the effect of stent replantation in goats to repair dural defects.Methods(1)The spatial structure and surface morphology of the spinal dura mater were observed,and the mechanical properties of dura mater were determined.The dura mater of goat was observed by naked eye,scanning electron microscope,transmission electron microscope,histological observation and tensile test.(2)The aligned nanofiber scaffolds which were similar to the natural dural space structure were prepared by electrospinning technology,then the scanning electron microscope,tensile test and water absorption rate of the scaffolds were measured.The cell planting experiment was also carried out to observe the growth of the cells on the scaffold.The contrast study was made with the most control of random nanofiber scaffolds.(3)The experiment and effect evaluation of nanofiber scaffolds for repairing dural defects in goat were carried out.Ten goats were randomly divided into two groups,all of which resulting in a dural defect model of 0.5 cm x 0.5 cm,and the two types of nanofiber scaffolds were placed in two Group goat body.One month after surgery,materials were obtained,visual inspection of the repaired area,histological light microscopy,and scanning electron microscopy were performed to evaluate the repair effect.Results(1)The dura mater is a milky translucent film that has a certain degree of elasticity and naturally recedes from the liquid environment.The dura mater is composed of collagen fibers and fibroblasts scattered in them,the collagen fibers have obvious directionality,and most of them are arranged axially and have less fibers in other directions.The diameter of the collagen fibers is between 10nm-90 nm.The surface of the dura mater is a bulge and indentation formed by the tight binding of collagen fiber bundles,as if the gully is connected and the continuous hills,and the collagen fibers have obvious directionality,mainly extending in the axial direction.(2)Because of the obvious orientation,the mechanical strength of the fiber oriented nanofibers is obviously greater than the mechanical strength perpendicular to the fiber orientation.There is no orientation in the fiber arrangement of the random nanofiber scaffolds.The mechanical strength of the two kinds of scaffolds is greater than the mechanical strength of the natural goat dural membrane,which can meet the mechanical requirements of the goat’s physiological activities.The hydrophilicity of the two kinds of scaffolds is close,and the biocompatibility is close too.The proliferation rate of cells on the two scaffolds was close,but the cells on the fiber oriented nanofibers extended along the direction of fiber arrangement,while the cells on the random nanofiber scaffolds grew in disc shape.(3)1 months after the operation,it was proved that the effect of the orientation nanofiber scaffold on the repair of the dural defect was better than that of the random nanofiber scaffold.Conclusions With PLGA as the raw material,the orientation nanofiber scaffolds and random nanofiber scaffolds prepared by electrostatic spinning technology can induce the growth of the dura collagenous fibers,guide the natural healing of the spinal meninges,and achieve the purpose of repairing the defects of the cerebrospinal fluid and the spinal cord,in which the orientated nanofiber scaffold is closer to the natural goat’s spinal cord.Membrane structure may be more suitable for repair of spinal dura mater damage.