Liposomes as delivery systems for nasal vaccination: strategies and outcomes.

IMPORTANCE OF THE FIELD: Among the particulate systems that have been envisaged in vaccine delivery, liposomes are very attractive. These phospholipid vesicles can indeed deliver a wide range of molecules. They have been shown to enhance considerably the immunogenicity of weak protein antigens or synthetic peptides. Also, they offer a wide range of pharmaceutical options for the design of vaccines. In the past decade, the nasal mucosa has emerged as an effective route for vaccine delivery, together with the opportunity to develop non-invasive approaches in vaccination. AREAS COVERED IN THIS REVIEW: This review focuses on the recent strategies and outcomes that have been developed around the use of liposomes in nasal vaccination. WHAT THE READER WILL GAIN: The various formulation parameters, including lipid composition, size, charge and mucoadhesiveness, that have been investigated in the design of liposomal vaccine candidates dedicated to nasal vaccination are outlined. Also, an overview of the immunological and protective responses obtained with the developed formulations is presented. TAKE HOME MESSAGE: This review illustrates the high potential of liposomes as nasal vaccine delivery systems.