IL-1 receptor antagonist as an aerosol in inflammation

The feasibility of efficient aerosol delivery of the human IL-1 receptor antagonist (IL-1Ra) for reduction of acute lung inflammation was demonstrated in a mouse model study. The therapeutic efficacy of dry powder formulations PM(2), PM(10) of IL-1Ra was studied at nonforced inhalation in an aerosol chamber using the DPI "Spinhaler". Micronized powder formulations for insufflation were produced by air-jet milling. The anti-inflammatory effect of IL-Ra preparation was assessed by differential cell counts and biochemical composition of bronchoalveolar lavage (BAL). Reactive oxygen species (ROS), metabolic parameters of BAL (pH, redox potential, total protein, and lactate), and morphological lung changes were investigated by methods of luminol-dependent chemoluminescence, electrochemistry, microscopy, optical, and NMR spectroscopy. Inhalation of IL-1Ra aerosol ensured the systemic absorption of IL-1Ra in the circulatory system and reduced the acute inflammatory response to intranasal lipopolysaccharide challenge. The inhaled anti-inflammatory dosage in aerosol administration appeared to be comparable with i.p. injection. The mechanism of positive action of pulmonary aerosol delivery of Il-Ra includes normalization of the oxidative activity of bronchoalveolar cells, prevention of neutrophil recruitment to the bronchoalveolar tract, and improving of cell respiration. The results were used to develop mathematical models of the anti-inflammatory effects of IL-Ra as functions of the doses and dispersion grades of IL-Ra preparations. Aerosol application of IL-Ra may be an apparent way for prophylactic treating of respiratory inflammation caused by bacterial antigens.