Fabrication and Characterization of Chitosan Nerve Conduits with Microtubular Architectures

Porous multi-channel chitosan conduits were fabricated using a novel phase-separation techniquewith an axial temperature gradient. First, porous chitosan tubes were made with a mold that was composedof two concentric polytetrafiuoroethylene tubes. Then 1%-3% (w/v) chitosan solution was injected into thechitosan tube while the two ends of the tube were closed with steel rods. Then the outside of the tube waswrapped with a layer of thermal insulating material to reduce the heat transfer through the outside, and thetubes were placed in a freezer. The resulting phase separation then occurred in the presence of an axialtemperature gradient. The porosity, microtubule diameter, and orientation were controlled by adjusting thepolymer concentration and temperature gradient. After the preparation course, no poisonous substancesremained on the conduits. The mechanical properties, swelling, and biodegradability of the chitosan conduitswere investigated, and a scanning electron microscope was used to observe the tubular morphology andgrowth of neuroblastoma cells (N2A, mouse) in the conduits. The results demonstrate that the multi-channelchitosan conduits have suitable mechanical strength, swelling, degradation properties, and nerve cell affinity,so they hold promise for use as neural tissue engineering scaffolds.