Implantable microdevice for peripheral nerve regeneration: materials and fabrications

Rapid innovations in tissue engineering have increased the likelihood that fabricated microdevices for neuro-regeneration can finally be applied to humans. The advent of microdevices has created strong interest in many fields, including diagnostics, drug/gene delivery, and tissue engineering. The integration of microfluidics and tissue engineering is believed to hold promise in applications for neuro-regeneration. Early clinical results suggest that the fabrication of microdevices with appropriate properties indeed yields multi-functional applications with enhanced efficacy and less adverse effects. A prerequisite for advancing this area of research is the development of apt devices for nerve restoration, which can provide molecular, electrical, and micro-environmental cues for efficient neuronal cell regeneration. Based on the increasing clinical application of fabrication methods and continued efforts to advance this technology, it is likely that microdevice fabrication will become an effective method for achieving the above-mentioned criteria. Therefore, the aim of this review is to provide basic information on the fabrication of microdevices by focusing exclusively on several kinds of biomaterials, such as biocompatible, biodegradable, non-conducting, conducing, elastomeric and thermoplastic materials with natural, synthetic polymers, inorganic biomaterials, and physiochemical parameter for neuro-regeneration. We also discuss distinctive nerve growth factors and neural cell types within the context of developing micro-based neuro-degenerative applications. The information provided in this review is important with regards to the safe and widespread use of microdevice fabrication, particularly in the neuro-regenerative field.