Physiomimetic lung extracellular matrix hydrogel enhances pulmonary recovery in a rat model of acute respiratory distress syndrome

Currently, the mortality of acute respiratory distress syndrome (ARDS) patients remains as high as 30-45% due to the scarcity of effective treatments. Extracellular matrix (ECM)-based therapies have been recently emerged for tissue regeneration in lung injury. The objective was to investigate the therapeutic capacity of lung ECM-derived hydrogel (L-HG) in a rat experimental model of ARDS. 12 Healthy and 12 ARDS LPS-induced Sprague-Dawley rats were randomly distributed into 2 experimental groups (n = 6, each one): Intratracheally instilled with 1) saline or 2) L-HG. 3 days after treatment, the lungs were excised and assessed for histopathological analysis. Neutrophil infiltration resulted 11 – fold greater (p < 0.001) in ARDS rats compared to controls. The ARDS L-HG group presented a 3-fold increase respect to controls (p=0.005) but, most importantly, resulted in a marked decrease respect to the ALI group (p<0.001). Therefore, this preliminary data suggests ECM-based therapy as a new acellular approach in the treatment of ARDS. Further immunomodulatory assays are still needed to assess how L-HG modulates local and systemic inflammation.