Potential Therapeutic Strategies and Substances for Facial Nerve Regeneration Based on Preclinical Studies

Abstract

Despite advances in microsurgical technology and an improved understanding of nerve regeneration, obtaining satisfactory results after facial nerve injury remains a difficult clinical problem. Among existing peripheral nerve regeneration studies, relatively few have focused on the facial nerve, particularly how experimental studies of the facial nerve using animal models play an essential role in understanding functional outcomes and how such studies can lead to improved axon regeneration after nerve injury. The purpose of this article is to review current perspectives on strategies for applying potential therapeutic methods for facial nerve regeneration. To this end, we searched Embase, PubMed, and the Cochrane library using keywords, and after applying exclusion criteria, obtained a total of 31 qualifying experimental studies. We then summarize the fundamental experimental studies on facial nerve regeneration, highlighting recent bioengineering studies employing various strategies for supporting facial nerve regeneration, including nerve conduits with stem cells, neurotrophic factors, and/or other therapeutics. Our summary of the methods and results of these previous reports reveal a common feature among studies, showing that various neurotrophic factors arising from injured nerves contribute to a microenvironment that plays an important role in functional recovery. In most cases, histological examinations showed that this microenvironmental influence increased axonal diameter as well as myelination thickness. Such an analysis of available research on facial nerve injury and regeneration represents the first step toward future therapeutic strategies.

Porous Organic Materials in Tissue Engineering: Recent Advances and Applications for Severed Facial Nerve Injury Repair

“…More and more studies have proved that the porous structure can give nerve conduits better biological characteristics, which is conducive to material exchange, nutrient transport, and cell migration at the injured site. At the same time, it can increase the loading rate of active factors, proteins and cells, which can provide a good repair environment for the injured site, thus promoting the repair of nerve injury [53,54]. Nowadays, with the development of 3D printing and electrospinning technology, the process of preparing porous or some special forms of scaffolds is becoming more and more mature, and research on the application of neural scaffolds has also made great progress.…”

Trigeminal Sensory Supply Is Essential for Motor Recovery after Facial Nerve Injury

“…Apart from the rather common idiopathic Bell’s palsy (incidence of 11.5–53.3 per 100,000 individuals a year) [ 2 , 3 ] and traffic accident injuries (brainstem hemorrhage, temporal bone fractures, or lacerations of the face), most facial nerve lesions are postoperative (removal of cerebellopontine angle tumors, acoustic neuroma surgery, or parotid resections because of malignancy). Despite the use of all available microsurgical techniques for repair of transected nerves, the recovery of facial tone, voluntary movement and emotional expression of the face remains poor [ 4 , 5 , 6 , 7 , 8 ].…”

Advances in Peripheral Nerve Injury Repair with the Application of Nanomaterials

“…Facial nerve injury remains a tough clinical conundrum and may cause long-lasting disability and poor life quality [137]. Spontaneous regeneration of the defective nerve is incredibly slow, and it involves random axonal regeneration, obstructive scar formation, and possibly neuroma [138].…”