Guiding Mesenchymal Stem Cells into Myelinating Schwann Cell-Like Phenotypes by Using Electrospun Core-Sheath Nanoyarns.

Nerve guidance conduit (NGC)-infilling substrates have been reported to facilitate the regeneration of injured peripheral nerves (PNs), especially for large nerve gaps. In this study, longitudinally oriented electrospun core-sheath nanoyarns (csNYs), consisting of a polylactic acid microfiber core and an electrospun nanofiber sheath, were fabricated for potential PN tissue engineering applications. Our novel csNY displayed a well-aligned nanofibrous surface topography, resembling the ultrastructure of axons and fascicles of a native PN system, and it also provided a mechanically stable structure. The biological results showed that the csNY significantly enhanced the attachment, growth, and proliferation of human adipose derived mesenchymal stem cells (hADMSC) and also promoted the migration, proliferation, and phenotype maintenance of rabbit Schwann cells (rSCs). Our csNY notably increased the differentiation capability of hADMSC into SC-like cells (hADMSC-SC), in comparison with a 2D tissue culture polystyrene plate. More importantly, when combined with the appropriate induction medium, our csNY promoted hADMSC-SC to express high levels of myelination-associated markers. Overall, this study demonstrates that our csNYs have great potential to serve as not only ideal in vitro culture models for understanding SC-axon interaction and SC myelination but also as promising NGC-infilling substrates for PN regeneration applications.