Experimental considerations concerning the use of stem cells and tissue engineering for facial nerve regeneration: a systematic review.
OBJECTIVE
Peripheral nerve trauma results in functional loss in the innervated organ, and recovery without surgical intervention is rare. Many surgical techniques can be used for repair in experimental models. The authors investigated the source and delivery method of stem cells in experimental outcomes, seeking to clarify whether stem cells must be differentiated in the injured facial nerve and improve the regenerative process.


METHODS
The following key terms were used: nervous regeneration, nerve regeneration, facial nerve regeneration, stem cells, embryonic stem cells, fetal stem cells, adult stem cells, facial nerve, facial nerve trauma, and facial nerve traumatism. The search was restricted to experimental studies that applied stem cell therapy and tissue engineering for nerve repair.


RESULTS
Eight studies meeting the inclusion criteria were reviewed. Different sources of stem and precursor cells were explored (bone marrow mesenchymal stem cells, adipose-derived stem cells, dental pulp cells, and neural stem cells) for their potential application in the scenario of facial nerve injuries. Different material conduits (vases, collagen, and polyglycolic acid) were used as bridges. Immunochemistry and electrophysiology are the principal methods for analyzing regenerative effects. Although recent studies have shown that stem cells can act as a promising bridge for nerve repair, considerable optimization of these therapies will be required for their potential to be realized in a clinical setting.


CONCLUSIONS
Based on these studies, the use of stem cells derived from different sources presents promising results related to facial nerve regeneration and produces effective functional results. The use of tubes also optimizes nerve repair, thus promoting greater myelination and axonal growth of peripheral nerves.
Assistant Professor, Laboratory of Experimental Neurology, Health Science Center, State University of Rio Grande do Norte, Mossoró, RN, Brazil. Electronic address: eudeseuler@hotmail.com.
Eudes
E
Euler de Souza Lucena
Adjunct Professor, Laboratory of Experimental Neurology, Health Science Center, State University of Rio Grande do Norte, Mossoró, RN, Brazil.
Fausto Pierdoná
FP
Guzen
Assistant Professor, Laboratory of Experimental Neurology, Health Science Center, State University of Rio Grande do Norte, Mossoró, RN, Brazil.
José Rodolfo
JR
Lopes de Paiva Cavalcanti
Associate Professor, Department of Morphology, Bioscience Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
Carlos Augusto
CA
Galvão Barboza
Adjunct Professor, Laboratory of Neuroanatomy, Department of Morphology, Bioscience Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
Expedito
E
Silva do Nascimento Júnior
Associate Professor, Laboratory of Neuroanatomy, Department of Morphology, Bioscience Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
Jeferson de Sousa
Jde S
Cavalcante
D000818:Animals; D020220:Facial Nerve Injuries / Q000503:physiopathology / Q000601:surgery*; D009416:Nerve Regeneration / Q000502:physiology*; D019635:Neurosurgical Procedures / Q000379:methods; D033581:Stem Cell Transplantation / Q000379:methods; D013234:Stem Cells / Q000145:classification / Q000502:physiology*; D023822:Tissue Engineering; D054457:Tissue Scaffolds / Q000145:classification