Preparation and Characterization of Nanoliposome Containing Isolated VP1 Protein of Foot and Mouth Disease Virus as a Model of Vaccine

Foot-and-mouth disease is an acute, highly contagious disease in livestock such as cattle, sheep, and pigs, causing a lot of economic losses in them. The Current Foot-and-mouth disease vaccines are formulated by inactivated whole-virus and adjuvant. This vaccine has been successful in the reduction of disease outbreaks in many regions of the world. Immunological studies on foot-and-mouth viruses have revealed that the dominant epitope in arising neutral antibody response is amino acid residues constructing G_H loop, which constitute a surface loop of the structural protein, termed VP1. Liposomes as one of the most well-known vehicles have been considered as an important carrier in vaccine development. Liposomes’ function regarding their size, charge, and lipid content used to encapsulate purified VP1 protein. Thus, the VP1 protein was isolated from the FMD virus. This study aims to compare four methods of VP1 protein encapsulation in the liposome and the effect of extruding on VP1 protein encapsulation. In the first method, VP1 protein dissolved in DMSO and added to the lipid film that is hydrated by ethanol. In the second method, the lipid film was hydrated by VP1 protein which contained 7M urea. In the third method, the lipid film was hydrated by VP1 protein then it was freeze-thawed, and in the last method, the lipid film hydrated by VP1 protein. The highest encapsulation efficiency was achieved %91 in the second method which purified protein-containing urea was used. The VP1 protein in the prepared liposome (DMPC: DMPG: Cholesterol) was released in excess of 90% of protein content after 240h.