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

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.

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 = 12), RLN transection with ipsilateral saline thyroarytenoid (TA) injection (n = 16), and RLN transection with ipsilateral pd-CTM TA injection. Outcomes included laryngeal electromyography (L-EMG) and video laryngoscopy after 7 and 28 days, with larynges then harvested and analyzed via immunohistochemistry (IHC) and qPCR.

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-β3), and anti-inflammatory factors (IL-10, IL-1Rα). 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 < 0.001). IHC detected innervated neuromuscular junctions 28 days after pd-CTM treatment.

pd-CTM may be a novel treatment option for patients with UVFP based on the neurotrophic, angiogenic, tissue remodeling, and anti-inflammatory factors present.

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