Fabrication and cellular compatibility of aligned chitosan-PCL fibers for nerve tissue regeneration

The ability to produce aligned sub-micron fibers may open new avenues for the development of scaffolds for application in tissue engineering and regenerative medicine. An area of particular interest is functional restoration of damaged or diseased nerves where the aligned fibers serve to support cell adhesion and proliferation, and guide neurite outgrowth in the direction of fiber orientation. In this study, we developed an aligned chitosan- polycaprolactone (chitosan-PCL) fibrous scaffold and investigated how the fiber alignment influenced nerve cell organization and function in comparison with randomly oriented fibrous scaffolds and cast films of the same material. Schwann cells (SCs) were shown to attach and proliferate on all the substrates regardless of their topography, demonstrating the cellular compatibility of the chitosan-PCL material. SCs grown on the aligned chitosan-PCL fibers exhibited a bipolar morphology that oriented along the fiber alignment direction, while those on the films and randomly oriented fibers had a multipolar morphology. Similarly, the chitosan-PCL material supported neuron-like PC-12 cell adhesion, and the aligned fibers regulated the growth of PC-12 cells along the fiber orientation. Additionally, PC-12 cells cultured on the aligned fibers exhibited enhanced unidirectional neurite extension along fiber orientation and significantly higher β-tubulin gene expression than those grown on chitosan-PCL films and randomly oriented fibers. Our investigation suggested that the aligned chitosan-PCL fibers can serve as a suitable scaffold for improved nerve tissue reconstruction.