Efficacy of photodynamic therapy in an experimental mice tuberculosis model

The objective: to study the efficacy of antimicrobial photodynamic therapy (APDT) using hydroxyaluminum phthalocyanine (Photosens) as a photosensitizer in the experimental model of tuberculosis infection in mice. Subjects and Methods. Balb/cmice were infected with the multiple drug resistant (MDR) strain of M. tuberculosis Beijing BO/W148. APDT with hydroxyaluminum phthalocyanine and red laser light exposure were started on Day 45. A total of 4 sessions of APDT on the projection of both lungs, liver and spleen were performed. On Day 60, the therapeutic eff ect of APDT was assessed by evaluation of severity of mycobacterial load and specific granulomatous infiltration in the lungs, liver and spleen. The absorption of light energy of laser radiation by the chest and abdominal walls, as well as tissues of lungs, liver and spleen was determined by photometry using afluovisor. Results. The tissues of the experimental animal retain a significant amount of light energy, however, the residual value of light transmission is sufficient to provide a pronounced therapeutic effect which manifests itself as a significant decrease of mycobacterial load and specific inflammatory process in all the studied internal organs. Conclusion. APDT may be an effective tool to treat some forms of tuberculous infection including those caused by M. tuberculosis with MDR.