Preparation and characterisation of zein/polyphenol nanofibres for nerve tissue regeneration

Bridging strategies are required to repair peripheral nerve injuries that result in gaps >5-8 mm. Limitations such as donor-site morbidity and size mismatches with receptor sites for autografts, together with immunological problems associated with allografts and xenografts, have created an increased interest in the field of manufactured nerve guide conduits. In this study, zein, a plant protein-based polymer, was electrospun to prepare nanofibrous mats. An important challenge with zein mats is the rapid change from fibre to film under aqueous conditions. Tannic acid (TA), which is a polyphenol, was selected to prepare a blend of zein/TA with different weight ratios to investigate its effect on the wetting resistance of nanofibres. The electrospun mats were characterised and evaluated by Fourier transform infrared spectroscopy and scanning electron microscopy (SEM). Also, degradation and mechanical properties of the mats were studied. Results showed that TA had a significant effect on the resistance to film formation in nanofibres. Moreover, the degradation and elongation at break of mats were increased with increase in TA concentration. For the investigation of the peripheral nerve regeneration potential, Schwann cells were selected for cytotoxicity evaluation by the 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide assay and cell morphology by SEM. Schwann cells had good biocompatibility with zein/TA blends (%) of 90/10 and 80/20.