Three-dimensional tissue-engineered skeletal muscle for laryngeal reconstruction.

Objective: There is an unmet need for tissue-engineered three-dimensional (3D) muscle constructs for laryngeal reconstruction. Functional engineered muscle could be used to repair postoncologic or traumatic defects or to medialize the vocal fold in cases of paresis/paralysis. Autologous, organized, engineered muscle that has adequate bulk integrates into host tissue and restores function currently does not exist.

Methods: Primary skeletal muscle progenitor cells (MPCs) were isolated from F344 rats. Three-dimensional muscle constructs were created by encapsulating MPCs via flow alignment in a customized collagen formulation and cultured under passive tension. Muscle-specific immunohistochemistry and confocal microscopy were used to evaluate muscle tissue differentiation. After 2 weeks of culture, muscle constructs were implanted into surgically created defects in the rat larynx. Postmortem function testing and histology was performed at 1 and 3 months.

Results: Immunohistochemistry with confocal microscopy demonstrated well-differentiated myotubes, which were well aligned and distributed throughout the engineered construct in vitro. There was evidence of restoration of normal laryngeal function at 1 month postoperative, as indicated by safe swallow (no aspiration events), weight gain, and excellent animal survival. Postmortem specimens demonstrated functional muscle contraction on ex vivo testing, and histology confirmed integration into host tissue.

Conclusion: This is the first study to demonstrate that functional, 3D tissue-engineered skeletal muscle can be developed from primary MPCs and standardized oligomeric collagen. Collectively, these findings may have tremendous clinical implications for autologous laryngeal muscle repair and reconstruction.

Level Of Evidence: NA. Laryngoscope, 128:603-609, 2018.