Surface modified liposomes for nasal delivery of DNA vaccine.

The aim of the present work was to investigate the potential utility of glycol chitosan coated liposomes as nasal vaccine delivery vehicle for eliciting viral specific humoral mucosal and cellular immune responses. Plasmid pRc/CMV-HBs(S) encapsulated liposomes were prepared by dehydration-rehydration method and subsequently coated with glycol chitosan by simple incubation method. Liposomes were then characterized for their size, surface charge, entrapment efficiency, and ability to protect encapsulated DNA against nuclease digestion and for their mucoadhesiveness. The liposomes were then administered to mice in order to study their feasibility as nasal vaccine carriers. The developed liposomes possessed +9.8 mV zeta potential and an average vesicle size less than 1 microm and entrapment efficiency of approximately 53%. Following intranasal administration, glycol chitosan coated liposomes elicited humoral mucosal and cellular immune responses that were significant as compared to naked DNA justifying the potential advantage of mucosal vaccination in the production of local antibodies at the sites where pathogens enters the body.