Affiliation:
1. Department of Otolaryngology‐Head and Neck Surgery Indiana University School of Medicine Indianapolis Indiana U.S.A.
2. Weldon School of Biomedical Engineering Purdue University West Lafayette Indiana U.S.A.
3. School of Medicine Indiana University School of Medicine Indianapolis Indiana U.S.A.
4. Department of Comparative Pathobiology Purdue University West Lafayette Indiana U.S.A.
Abstract
ObjectiveVocal fold paralysis impairs quality of life, and no curative injectable therapy exists. We evaluated injection of a novel in situ polymerizing (scaffold‐forming) collagen in the presence and absence of muscle‐derived motor‐endplate expressing cells (MEEs) to promote medialization and recurrent laryngeal nerve (RLN) regeneration in a porcine model of unilateral vocal fold paralysis.MethodsTwelve Yucatan minipigs underwent right RLN transection. Autologous muscle progenitor cells were isolated from muscle biopsies, differentiated, and induced to MEEs. Three weeks after RLN injury, animals received injections of collagen, collagen containing MEEs, or saline into the paralyzed right vocal fold. Stimulated laryngeal electromyography and acoustic vocalization were used for function assessments. Larynges were harvested and underwent histologic, gene expression, and further quantitative analyses.ResultsInjections were well‐tolerated, with the collagen scaffold showing immunotolerance and collagen‐encapsulated MEEs remaining viable. Collagen‐treated paralyzed vocal folds showed increased laryngeal adductor muscle volumes relative to that of the uninjured side, with those receiving MEEs and collagen showing the highest volumes. Muscles injected with MEEs and collagen demonstrated increased expression of select neurotrophic (BDNF and NTN1), motor‐endplate (DOK7, CHRNA1, and MUSK), and myogenic (MYOG and MYOD) related genes relative to saline controls.ConclusionIn a porcine model of unilateral vocal fold paralysis, injection of in situ polymerizing collagen in the absence and presence of MEEs enhanced laryngeal adductor muscle volume, modulated expression of neurotrophic and myogenic factors, and avoided adverse material‐mediated immune responses. Further study is needed to determine long‐term functional outcomes with this novel therapeutic approach.Level of EvidenceNA Laryngoscope, 2024
Funder
National Institute on Deafness and Other Communication Disorders