Photodynamic inactivation of Escherichia coli bacteria by cationic photosensitizers

The aim of this work is the study of antibacterial photodynamic inactivation (APDI) of Escherichia coli (on the example of a model E. coli K12 TG1), the influence of the charge of photosensitizer (PS) molecules on the efficiency of binding with these Gram-negative bacteria. The results obtained confirm that PSs based on polycationic phthalocyanines and synthetic bacteriochlorins provide effective photodynamic inactivation of E. coli, much higher than monocationic methylene blue and electro-neutral bacteriochlorin derivative. The efficiency of APDI, assessed by the intensity of bioluminescence of model E. coli K12 TG1 bacteria, correlates with the charge of PS molecules and the efficiency of electrostatic binding of PS to bacterial cells.