Evaluating the Efficacy of Chitosan-l-DOPA MAP Gel for Acute Laryngeal Injury

This study aimed to evaluate the efficacy of an innovative chitosan-l-DOPA-modified microporous annealed particle (MAP) hydrogel in reducing fibrosis and enhancing healing in the treatment of Acute Laryngeal Injury (ALgI).

Four experimental treatment groups: uninjured control, sham treated control (saline), nonbioactive MAP gel (sMAP), and Chitosan-l-DOPA MAP gel (dMAP2) were evaluated in a validated rabbit model of acute laryngeal injury, consisting of posterior glottis mucosal stripping and debridement followed by treatment at 14 days postinjury. At Days 4 and 14 posttreatment, histological evaluations were performed to evaluate the posterior glottic thickness (PGT), collagen content and type within the posterior glottis via immunofluorescence staining, glycosaminoglycan (GAG) content via Alcian blue staining, and collagen fiber orientation through picrosirius red staining.

At Day 4, the dMAP2 treatment performed similarly to the standard MAP gel, indicating a consistent inflammatory profile. Though at Day 14, the dMAP2 treated injuries demonstrated a significant increase in PGT compared to uninjured controls (p < 0.001), the healing wound expressed a significant increase in collagen area, including collagen I, collagen III, and colocalized species (p < 0.05). The alignment of collagen fibers within the tissue was consistent with the uninjured sample compared to the untreated injury. In a similar relationship, dMAP2 treated wounds led to similar GAG expression within the cricoarytenoid joint as the uninjured tissue, compared to the untreated injury consistent with a reduced arthritic condition.

The dMAP2 gel improved healing with organized tissue remodeling compared to untreated controls through the proliferative phase of wound healing.

3.