Treatment of pulmonary
infections caused by Mycobacterium abscessus are extremely difficult to treat, as this species is naturally resistant to many common
antibiotics.
Liposomes are vesicular nanocarriers suitable for hydrophilic and lipophilic
drug loading, able to deliver drugs to the target site, and successfully used in different
pharmaceutical applications. Moreover,
liposomes are biocompatible, biodegradable and nontoxic vesicles and nebulized
liposomes are efficient in targeting
antibacterial agents to macrophages. The present aim was to formulate
rifampicin-loaded
liposomes (RIF-Lipo) for lung delivery, in order to increase the local concentration of the
antibiotic. Unilamellar liposomal vesicles composed of anionic
DPPG mixed with HSPC for
rifampicin delivery were designed, prepared, and characterized. Samples were prepared by using the thin-film hydration method. RIF-Lipo and unloaded
liposomes were characterized in terms of size, ΞΆ-potential, bilayer features, stability and in different
biological media.
Rifampicin's entrapment efficiency and release were also evaluated. Finally,
biological activity of RIF-loaded
liposomes in Mycobacterium abscessus-infected macrophages was investigated. The results show that RIF-lipo induce a significantly better reduction of intracellular Mycobacterium abscessus viability than the treatment with free
drug.
Liposome formulation of
rifampicin may represent a valuable strategy to enhance the
biological activity of the
drug against intracellular mycobacteria.