Effects of Schwann cell alignment along the oriented electrospun chitosan nanofibers on nerve regeneration

Abstract

We have constructed a chitosan nonwoven nanofiber mesh tube consisting of oriented fibers by the electrospinning method. The efficacy of oriented nanofibers on Schwann cell alignment and positive effect of this tube on peripheral nerve regeneration were confirmed. The physical properties of the chitosan nanofiber mesh sheets prepared by electrospinning with or without fiber orientation were characterized. Then, immortalized Schwann cells were cultured on these sheets. Furthermore, the chitosan nanofiber mesh tubes with or without orientation, and bilayered chitosan mesh tube with an inner layer of oriented nanofibers and an outer layer of randomized nanofibers were bridgegrafted into rat sciatic nerve defect. As a result of fiber orientation, the tensile strength along the axis of the sheet increased. Because Schwann cells aligned along the nanofibers, oriented fibrous sheets could exhibit a Schwann cell column. Functional recovery and electrophysiological recovery occurred in time in the oriented group as well as in the bilayered group, and approximately matched those in the isograft. Furthermore, histological analysis revealed that the sprouting of myelinated axons occurred vigorously followed by axonal maturation in the isograft, oriented, and bilayered group in the order. The oriented chitosan nanofiber mesh tube may be a promising substitute for autogenous nerve graft.

Preparations, properties and applications of chitosan based nanofibers fabricated by electrospinning

“…The study indicated that the chitosan nano/microfiber mesh tubes with a DD of 93% have sufficient mechanical properties to preserve tube space, provide a better scaffold for cell migration and attachment, and facilitate humoral permeation to enhance nerve regeneration. Afterwards, Wang et al [111] constructed a chitosan nonwoven nano fiber mesh tube consisting of oriented fibers by the electrospinning method. The efficacy of oriented nanofibers on Schwann cell alignment and positive effect of this tube on peripheral nerve regeneration were confirmed.…”

Aberrant gastrocnemius muscle innervation by tibial nerve afferents after implantation of chitosan tubes impregnated with progesterone favored locomotion recovery in rats with transected sciatic nerve

“…It is difficult to compare the kinematics with other studies due to the different methodologies. 3,4,30,34,36,[53][54][55][56] A previous study 4 demonstrated that when a chitosanplus-progesterone tube is implanted in sectioned peripheral facial nerves of rabbits, progesterone allows the anatomical recovery of the nerve morphology. In contrast, Rosales-Cortes et al 39 found no differences in dog sciatic nerve morphology, even when the nerves were repaired with chitosan alone or chitosan plus progesterone tubes.…”

Biodegradable Cell-Seeded Nanofiber Scaffolds for Neural Repair

“…They attributed this to the cellular topographic cues as well as the molecular cues provided by the Schwann cells [289]. Wang et al also examined the efficacy of using a Schwann cell seeded aligned electrospun chitosan fibrous tube to repair a 10-mm sciatic nerve defect in a rat model [290]. The in vitro study confirmed the alignment of Schwann cells on the aligned electrospun fibers.…”

“…Sensory and motor functional recovery together with electrophysiological recovery was observed. They also compared the single layer aligned nanofiber tube with a bi-layer tube (aligned nanofiber inner layer and random fiber outer layer) and concluded that the outer layer of the tube was not necessary to provide mechanical strength [290]. Figure 9 shows Schwann cells cultured on both random and oriented electrospun chitosan nanofiber coverslips.…”