Oxygenation through oral Ox66 in a two-hit rodent model of respiratory distress

Acute respiratory distress syndrome (ARDS) is a complication of pulmonary disease that produces life-threatening hypoxaemia. Despite ventilation and hyperoxic therapies, undetected hypoxia can manifest in capillary beds leading to multi-organ failure. Ox66™ is an ingestible, solid-state form of oxygen designed to supplement oxygen deficits. Twenty-four anaesthetized rats underwent a two-hit model of respiratory distress (ARDS), where a single dose (5 mg/kg) of lipopolysaccharide (LPS) was given intratracheally, and then the respiratory tidal volume was reduced by 40%. After 60 min, animals were randomized to receive Ox66™, or normal saline (NS; vehicle control) via gavage or supplemental inspired oxygen (40% FiO₂). A second gavage was administered at 120 min. Cardiovascular function and blood oximetry/chemistry were measured alongside the peripheral spinotrapezius muscle's interstitial oxygenation (P_ISFO₂). ARDS reduced mean arterial pressure (MAP) and P_ISFO₂ compared to baseline (BL) for all treatment groups. Treatment with Ox66 or NS did not improve MAP, but 40% FiO₂ caused a rapid return to BL. P_ISFO₂ improved after treatment with Ox66^™ and 40% FiO₂ and remained elevated for both groups against NS until study conclusion. Both oxygen treatments also suppressed the inflammatory response to LPS, suggesting that Ox66^™ can deliver therapeutically-impactful levels of oxygen in situations of pulmonary dysfunction.