Immunomodulatory Extracellular Matrix Hydrogel Mitigates Scar Formation in a Model of Tongue Fibrosis

Background While head and neck cancer treatment regimens, including surgical resection, irradiation, and chemotherapy, are effective at removing tumors, they lead to muscle atrophy, denervation, and fibrosis, contributing to the pathogenesis of tongue dysphagia – difficulty swallowing. Current standard of care is ineffective; we propose an alternative approach utilizing an acellular and minimally invasive biomaterial to preserve muscle content and reduce fibrosis of the tongue after injury. Here, we investigate a decellularized extracellular matrix hydrogel for the treatment of tongue fibrosis in a partial glossectomy injury model. Methods Skeletal muscle extracellular matrix (SKM) hydrogel was fabricated by decellularizing porcine skeletal muscle tissue through established protocols. A partial glossectomy injury in the rat was used as a model of tongue fibrois, and SKM hydrogels along with saline controls were injected to the site of scarring two weeks after injury. Tissues were harvested at 3 and 7 days post-injection for gene expression analysis of immune and myogenic pathways, and at 4 weeks post-injection to evaluate histomorphological changes in skeletal muscle and scar formation. Results SKM hydrogel reduced scar formation and improved muscle fiber cross-sectional area in the region of injury compared to saline controls. SKM upregulated pro-regenerative immune response while downregulating pro-inflammatory response and further promoted angiogenic gene expression. Conclusion This study demonstrates the immunomodulatory and tissue-regenerative capacity of an acellular and minimally invasive biomaterial in a rodent model of tongue fibrosis.