Development of a nanobiotechnological product composed of bacteriophage-encoded endolysins: strategies for biofilm controlling in endotracheal tubes

Abstract

Biofilms are etiologic agents of several infectious diseases, mainly those healthcare-associated infections. Dental-medical-hospital devices or health products, such as endotracheal tubes, present adequate conditions for biofilm formation and, consequently, the development of infections, worsening the patients' clinical condition. The impact of biofilms on health has promoted the development of different approaches, aimed at controlling this source of contamination. The successful results in phage-therapy have led to new research involving bacteriophages and enzymes encoded by the viruses to control biofilms. However, scientific evidences on the use of endolysins to control biofilms formed by gram-negative bacteria are scarce due to the difficulty of enzymes in crossing the outer membrane of the bacterial cell wall to act on peptidoglycans. Thus, the objective of this research proposal will be to clone, express, purify and characterize the endolysins of bacteriophages vB_PaeM_USP_2 and vB_PaeM_USP_18, which have high lytic potential and were recently described in the scientific literature by our research group. The antibacterial activity and potential antibiofilm applicability of recombinant enzymes, encapsulated in liposomes, will be evaluated in vitro and ex vivo against Pseudomonas aeruginosa strains. In addition, a nanobiotechnological endotracheal tube covered by recombinant endolysins encapsulated in liposomes will be investigated in situ and in vivo using a flow-cell biofilm formation model and a pig model in mechanical ventilation, respectively. Finally, the activation of the innate immune response will be evaluated, in vitro, through the response of neutrophils and monocytes in the presence of recombinant endolysins, aiming to clarify whether nanobiotechnological formulations activate an immune response and whether they are safe for future clinical use. (AU)