Photodynamic Therapy under Diagnostic Control of Wounds with Antibiotic-Resistant Microflora

Abstract

Background: Difficulties in the treatment of purulent wounds are caused by bacterial biofilms, which results in decontamination limitations. Infected wounds are not sufficiently susceptible to existing antibiotics, necessitating the search for alternative approaches to reduce the concentration of pathogenic microflora. Methods: This study describes an approach to the effective treatment of wounds by photodynamic inactivation or therapy (PDI/PDT) of antibiotic-resistant microflora under fluorescence control. For this purpose, laser and LED light (660–680 nm) and different groups of photosensitizers (PS) (1% solutions of methylene blue, aluminum phthalocyanine, chlorine e6 and nanocomposites containing these groups of PS) were used. The study included 90 patients with various wounds. Some patients were subjected to fluorescence diagnosis by laser spectral analysis before the PDT. Results: Positive results were achieved in 76 patients (84%, p < 0.05). After the first PDT session, a decrease in the concentration of microflora was noticeable. By the third and seventh days, a significant to complete inactivation of bacteria was obtained. In all patients who were photo-diagnosed before PDT, a significant PS concentration decrease of more than 75% after PDT was obtained. Conclusion: PDT is an effective method for the inactivation of antibiotic-resistant pathogens, including in long non-healing wounds, contributing also to early tissue regeneration.

Keywords

• photodynamic therapy
• nano photosensitizers
• fluorescence diagnosis
• infected wound
• antibiotic-resistant microflora
• decontamination