Bioinspired hierarchical fibre bundles from microfluidics for nerve regeneration

Fibre-shaped scaffolds have demonstrated value in nerve tissue engineering because of their ability to direct cell alignment and remodel intrinsic fibrous tissues. Research in this aspect focuses on the creation of microfibres with nerve-mimicking morphology and spatial neurocyte guidance to improve the regeneration effects. Here, inspired by the anatomical structure of the nerve that is composed of parallelly assembled nerve fibres, we present novel hierarchical fibre bundles from microfluidics for peripheral nerve regeneration. The GelMA/alginate filaments encapsulated in hydrogel microfibre shells were consecutively generated from the coaxially assembled capillary microfluidic device, and their composition and morphology could be further tuned by changing the microchannel and fluid constructions. Based on the resultant microfibres, we have demonstrated that they could provide a biomimicking cell culture environment and promote the formation of nerve bundles. In addition, the hierarchical fibre bundles showed an improved regeneration capability of sciatic nerves when they were transplanted into sciatic nerve defect SD rat models. Thus, hierarchical fibre bundles are potentially valuable for clinical peripheral nerve regeneration.