Peripheral nerve injury: Current challenges, conventional treatment approaches and new trends on biomaterials-based regenerative strategies

Damage to peripheral nerves is a widely extended health problem, causing important socio-economic costs worldwide. Indeed, peripheral nerve injuries (PNI) have been concerning the medical community for many decades. Nevertheless, despite the increase in knowledge in the injury physiopathology and the great research efforts being undertaken, the current standard grafting strategies used to repair PNI are not as efficient as desired. Although alternative engineered nerve grafts are already commercialized, their clinical performance is suboptimal. In this review, a general description of the circumstances and repercussions surrounding the PNI pathological state are presented, together with the treatment limitations and current challenges when addressing both short- and long-gap defects. In addition, potential therapeutic molecules are considered, while innovative regenerative strategies have been identified. Finally, the most relevant advances on the use of a wide range of biomaterials for the development of novel medical devices are also overviewed in depth, either considering strategies making use of empty or filled nerve conduits for guided tissue regeneration.