Phospholipid vesicles encapsulated bacteriophage: A novel approach to enhance phage biodistribution.

Phage therapy has been at the centre of attraction for combating multi-drug resistant strains. However, less stability and rapid clearance of phage by mononuclear phagocytic system (MPS) restricts its use in humans. In the present study, aim was to develop a liposomal delivery system for bacteriophage that can assure efficient phage delivery and retention at the site of infection. Different ratios of cholesterol, lipids and surfactant along with different charge inducers were employed to prepare liposomes. Phage was then entrapped in the liposomes and characterized on the basis of morphology, size, entrapment efficiency and stability. Further, in vivo biodistribution of free phage and liposome entrapped phage was compared in different organs of mice. A cationic liposomal formulation showed maximum encapsulation efficiency of 92%. Transmission electron microscopy (TEM) confirmed the entrapment of phages in liposomes. Liposome preparation was found to be most stable at 4°C during storage. Liposome entrapped bacteriophage was retained for longer duration in different organs i.e. upto day 4 in blood, day 6 in liver, lungs and kidney, 14days in spleen of mice as compared to free phage that became undetectable by 36th h in blood as well as lungs and by 48th h in all other organs.