Placental-Derived Connective Tissue Matrix Mediates Murine Recurrent Laryngeal Nerve Regeneration.

Abstract

OBJECTIVE: Unilateral vocal fold paralysis (UVFP) due to recurrent laryngeal nerve (RLN) injury is a common cause of dysphonia. No biotherapeutic injectable exists that directs laryngeal reinnervation after RLN injury. Placental-derived connective tissue matrix (pd-CTM) could fill this need, as it contains a plethora of cytokines with potential UVFP therapeutic benefits. This study aimed to identify and quantify the factors in a commercially available pd-CTM (CTM Flow, CTM Biomedical, Lake Worth, Florida) and to study the effects of pd-CTM on vocal fold microenvironment and glottic function in a mouse model of unilateral RLN injury. METHODS: Cytokine expression (ng/mL) in pd-CTM was characterized using a cytokine array and ELISA. In a separate experiment, C57/BL6 mice were divided into three groups: uninjured negative controls (n&#x2009;=&#x2009;12), RLN transection with ipsilateral saline thyroarytenoid (TA) injection (n&#x2009;=&#x2009;16), and RLN transection with ipsilateral pd-CTM TA injection. Outcomes included laryngeal electromyography (L-EMG) and video laryngoscopy after 7 and 28&#x2009;days, with larynges then harvested and analyzed via immunohistochemistry (IHC) and qPCR. RESULTS: pd-CTM characterization showed moderate-to-high levels of neurotrophic (BDNF, CNTF, GDNF, NTF-3), angiogenic (Angiogenin, VEGF-D), tissue remodeling (bFGF, IGF-1, HGF, TGF-&#x3b2;3), and anti-inflammatory factors (IL-10, IL-1R&#x3b1;). L-EMG demonstrated increased mean normalized area under the curve ratio in pd-CTM treated mice compared to saline treated mice at the 28-day time point indicating reinnervation (p&#x2009;<&#x2009;0.001). IHC detected innervated neuromuscular junctions 28&#x2009;days after pd-CTM treatment. CONCLUSION: pd-CTM may be a novel treatment option for patients with UVFP based on the neurotrophic, angiogenic, tissue remodeling, and anti-inflammatory factors present. LEVEL OF EVIDENCE: NA.