Modulation of myelin formation by combined high affinity with extracellular matrix structure of electrospun silk fibroin nanoscaffolds

Abstract

Remyelination is a major therapeutic goal in peripheral nerve regeneration, serving to restore function of demyelinated axons and provide neuroprotection. In order to apply myelin biogenesis strategies to peripheral nerve defects, the tissue engineered substitutes might be amenable to the promotion of this repair process. Electrospun nanofibers are considered as promising scaffolds for tissue engineering due to extracellular matrix mimicking factor and enhanced electrostatic interaction resulting in a controllable 3 D nanofibrous membrane. In order to explore the role of electrospun silk fibroin (SF) membrane in myelination, co-culture of dorsal root ganglion (DRG) neurons and Schwann cells (SCs) in vitro was established and observed. Scanning electron microscopy was used to observe DRG adhesion to the membranes, the electrospinning SF membrane is more favorable to the adhesion of DRG. The immunofluorescence staining of MAG and NF showed considerable amount of myelin were formed, and the myelin was tightly wrapped around the axons of the neurons, which was confirmed under the scanning electron microscope observation. Real-time quantitative PCR technique was used to determine the gene expression level of DRG neurons cultured at different time points. The results showed that the mRNA levels of N-cadherin, laminin, fibronectin were higher than those in the control group. Our results showed that the electrospun SF nanofibers can provide topographical and chemical cues that mimic (to a certain extent) the extracellular matrix.