PneumoPhageKill: development of a therapeutic system containing nanoencapsulated strictly lytic bacteriophages for Pseudomonas aeruginosa, for the treatment of bacterial pneumonia via nebulization

Abstract

The emergence of bacterial strains resistant to antibiotics and poor penetration of antibiotics in bacterial biofilms puts emphasis on the need for safe and effective alternatives for antimicrobial treatment. The application of strictly lytic bacteriophage (or phage) has been proposed as an alternative (or supplement) to conventional antibiotics, allowing the release of natural predators of bacteria directly at the site of infection. Probably the biggest advantage of phage-based therapies lies in the fact that the phage replicates directly at the site of infection, becoming widely available where they are most needed. When compared to antibiotics, phages have several important advantages: (i) increasing and permanently high concentrations at the site of infection in the presence of (viable) bacteria being disposed just after eradication of the bacterial host, (ii) full compatibility with antibiotics, (iii) specific against target bacteria, (iv) greater penetration of bacterial biofilm, by inducing production of enzymes that hydrolyze the polymeric matrix of the biofilm, and (v) while bacteria may develop resistance to phage, isolation and large scale production of new phages is much more simple and economical than developing new antibiotics. Water in oil in water (W/O/W) multiple emulsions are examples of emulsions where small water droplets are dispersed in larger droplets of oil, which in turn are dispersed in a continuous aqueous phase. Because of their compartimentalized internal structure, multiple emulsions are advantageous for encapsulation compared to simple O/W emulsions, such as the ability to transport both polar and nonpolar molecules, and allow a better control of the release of therapeutic molecules. This research project will investigate the potential of nanoencapsulating a lytic phage (or lytic phage cocktail) with broad-spectrum capable of infecting Pseudomonas aeruginosa. The physico-chemical characterization of the phage encapsulating nanoformulation include the determination of particle size and particle size distribution via analysis of the zeta potential, surface morphology via SEM / TEM, encapsulation efficiency and thermal analysis by DSC. The antimicrobial activity of nanoemulsions with encapsulated phage particles produced will also be tested in vitro. (AU)