Fabrication of Inner Grooved Hollow Fiber Membranes Using Microstructured Spinneret for Nerve Regeneration

Nerve conduits with topographical guidance have been recognized as the efficient repair of damaged peripheral nerves. In this study, polymeric hollow fiber membranes (HFMs) with grooved inner surface have been fabricated from a microstructured spinneret using a dry-jet wet spinning process for nerve regeneration studies. The effectiveness of HFM inner grooves has been demonstrated during an in vitro study of chick forebrain neuron outgrowth. It is of great importance that the groove geometry can be controllable to meet various needs in promoting nerve regeneration performance. While the overall groove geometry is determined by the spinneret design, fabrication conditions are also indispensable in fine-tuning the final groove geometry such as the groove height and width on the order of 10 μm or less. It is found that the bore fluid flow rate can be utilized to effectively adjust the resulting groove height by at most 52% and groove width by at most 61%, respectively, without modifying the spinneret geometry. This enables a new approach to fabricate different grooved HFMs using the same spinneret. By comparing to the influences of bore fluid flow rate, the dope fluid flow rate is less effective in regulating the groove height and width when using the same microstructured spinneret. Both bore and dope fluid flow rates should be carefully selected for fine groove width tuning.