RESUMO
Ricin toxin may be used as a biological warfare agent and no medical countermeasures are currently available. Here, a well-characterized lot of ricin was aerosolized to determine the delivered dose for future pre-clinical efficacy studies. Mouse intraperitoneal (IP) median lethal dose (LD50 ) bioassay measured potency at 5.62 and 7.35 µg/kg on Days 0 and 365, respectively. Additional analyses included total protein, sodium dodecyl sulfate polyacrylamide gel electrophoresis, Western blotting, and rabbit reticulocyte lysate activity assay. The nebulizer aerosol produced consistent concentrations (2.5 × 103 , 5.0 × 103 , 1.0 × 104 , and 1.5 × 104 µg/mL) and spray factor values. The aerosol particle size distribution was of sufficient size to deposit in lung alveoli (1.12-1.43 µm). Ricinus communis Agglutinin II (RCA 60), prepared at 19 mg/mL in phosphate-buffered saline, pH 7.8, and stored at -70°C, maintained attributes for toxicity following 1-year storage and aerosolized consistently.
