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The Carboxyl-terminal 19 kDa fragment of merozoite surface protein-1 of Plasmodium falciparum (PfMSP-119) was delivered directly into the cytoplasm via pH sensitive liposome. we have reported the preparation and characterization of PfMSP-119 encapsulated pH-sensitive liposomal formulations using oleyl alcohol (OAlc) in combination with egg phosphatidylcholine (EPC)and evaluated for intracellular cytosolic delivery of PfMSP-119 and as is evident from the results obtained; promising and significant immune responses were obtained by the cytosolic delivery of the malaria antigen through pH sensitive liposome. Moreover, after intramuscular immunization of PfMSP- 119 loaded pH sensitive liposomes, into Balb/c mice, the significant and perdurable IgG responses were obtained, as compared to conventional liposome loaded with PfMSP-119 and comparative evaluations have been marked with alum adsorbed malaria antigen. This may be attributed to good immuno-adjuvant action of pH sensitive liposomes, which are reported to enhance the immunogenicity of a soluble malaria antigen and present study might open new ways for the feasibility for the development of blood stage malaria vaccine.

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