Evaluation of the Pulmonary and Systemic Immunogenicity of Fluidosomes, a Fluid Liposomal-tobramycin Formulation for the Treatment of Chronic Infections in Lungs

In previous studies, we have developed a fluid bactericidal liposomal formulation containing tobramycin, called Fluidosomes, which has been shown to be highly bactericidal both in in vitro and in in vivo studies against Pseudomonas aeruginosa and other related and unrelated bacteria. One foreseeable application of these Fluidosomes is the treatment of chronic pulmonary infections in cystic fibrosis patients colonized with P. aeruginosa and other related bacteria. Considering the capacity of some liposomal preparations to play an adjuvant role in vaccines, the non-immunogenicity of Fluidosomes has to be demonstrated. The systemic and local immunogenicity of Fluidosomes were assessed by effectuating repeated intraperitoneal (i.p.) and intratracheal (i.t. ) immunizations in BALB/c mouse. No significant mucosal and serum immune responses against Fluidosomes and/or tobramycin were detected as compared with preimmune sera. These data suggest that Fluidosomes could be administered repeatedly without adverse immune responses to control chronic pulmonary infections in cystic fibrosis.