Injection of vocal fold lamina propria-derived hydrogels modulates fibrosis in injured vocal folds

Abstract:

Vocal fold (VF) fibrosis, often resulting from phonosurgery, radiation, or trauma, causes irreversible voice dysfunction due to excessive ECM deposition and increased tissue stiffness. No FDA-approved treatments for VF fibrosis exist, highlighting the need for novel antifibrotic therapies. TGF-β1 contributes to fibroblast-to-myofibroblast activation, leading to increased ACTA2 expression and collagen production via SMAD3, YAP1, and integrin signaling pathways. Leveraging the principle that local cells respond to tissue-specific signals, our ECM hydrogel, derived from decellularized vocal fold lamina propria (VFLP-ECM), reduced ACTA2 expression in TGF-β1-stimulated VF fibroblasts, showcasing antifibrotic potential. This study evaluates the therapeutic potential of VFLP-ECM hydrogel in a rabbit VF injury model. VFLP-ECM hydrogel or bovine type I collagen injections were administered 7 days post-injury and evaluated on day 28. We compared two VFLP-ECM formulations: a manual process (VFLP (man)) and an accelerated automated method (VFLP (au)). VFLP (man) modulated fibrosis-associated gene expressions more effectively than controls. Proteomics identified 229 proteins uniquely preserved in VFLP (man), including vitronectin, crucial in TGF-β1 signaling and ECM remodeling. Transcriptomic analysis suggests downregulation of fibrotic markers and inhibition of SMAD3, YAP1, and MRTFA, alongside upregulation of SMAD7, an inhibitor of TGF-β signaling. Notably, VFLP (man) treatment recovered stiffness comparable to uninjured controls (1.84 vs. 1.94 mN), whereas collagen-treated tissues remained stiff (2.7 mN), similar to the injury group (2.6 mN), indicating incomplete mechanical recovery. These in vivo data show that manually decellularized VFLP-ECM hydrogel attenuates fibrosis by disrupting key biochemical and mechanical cues driving myofibroblast activation.

Keywords:

Vocal fold lamina propria; Fibrosis; Extracellular matrix; Hydrogels; TGF-β1.