Evaluation of Protective Effects of PLGA Nanoparticles Containing Detoxified Lipopolysaccharide (LPS) Derived from Acinetobacter Baumannii in Mouse Lung Infection

common microbial pathogens with antibiotic resistance in causing respiratory infections in patients admitted to the ICU. Making a vaccine can be one of the effective ways to combat this infection. This study was performed to evaluate the protective effects of PLGA nanoparticles containing detoxified lipopolysaccharide (D-LPS) of Acinetobacter baumannii as a vaccine in mouse lung infection. Müller Hinton Broth culture medium was used for mass propagation of bacteria. Bacterial LPS was extracted by hot water-phenol method and detoxified with 0.2M NaOH. Encapsulation of detoxified LPS in PLGA particles was performed by Double emulsion solvent evaporation (Water/Oil/Water emulsion). The prepared particles were between 150 and 200 nm in diameter with a negative surface charge. Forty Balb/C mice were randomly divided into four groups of 10 (control, PLGA-receiving group, D-LPS-receiving group, and PLGA-D-LPS-receiving group). All groups were vaccinated three times at intervals of 14 days. On day 35, live bacteria were delivered to the groups through the lungs, and after 48 hours, the mice’s lungs were removed for bacteriological and histopathological studies. Culture of homogenized extract of lung tissue showed a significant difference between group 4 and other groups. (P <0.05) Histological study also showed the protective effect of PLGA nanoparticles containing detoxified LPS. This study showed that PLGA particles containing detoxified LPS of Acinetobacter baumannii were successful in stimulating the immune system of mice and could be used as a vaccine..