The World Health Organisation is convinced that one of the greatest threats to humanity is the rapidly growing resistance of bacteria to antibiotics due to their uncontrolled use. One Russian scientific project, the physical part carried out by specialists at MEPhI, offers a possible solution to this problem.
The new development will facilitate the treatment of hard-to-heal wounds, burns, and other foci of the bacterial threat, the authors claim.
Scientists believe that one solution to this global challenge could be the development of antibacterial photodynamic therapy (aPDT). According to numerous studies, pathogens cannot develop resistance to this type of treatment.
The antimicrobial effect of aPDT is based on the use of special substances, photosensitisers, which are injected into the body and irradiated with light using a special emitter in the course of treatment. The resulting light energy is transmitted to oxygen molecules and transformed into an active form that fights the infection.
A team of scientists, including physicists from the Prokhorov General Physics Institute of the Russian Academy of Sciences (GPI RAS) and National Research Nuclear University MEPhI, microbiologists from the Gamaleya Research Institute, and chemists from the State Scientific Centre “Research Institute of Organic Semi-Products and Dyes” (NIOPIK), suggested the use of synthetic polycationic bacteriochlorins as photosensitisers. Unlike most antibiotics that target only one type of bacteria, these compounds have a universal effect in aPDT treatment. Scientists believe that this will eliminate the need to identify the type of bacterial threat in clinical practice, thereby saving time and resources.
According to the WHO’s guidelines, any drug that reduces the number of active pathogen cells by at least 103 times is considered to be an effective antibacterial agent. According to MEPhI scientists, the bacteriochlorins they use exceed this figure by at least 10 times.
First of all, this efficiency is achieved due to the potent ability of bacteriochlorins to absorb light and subsequently transfer energy to the oxygen present in the body. The rapid destruction of bacteria is ensured by the effect of the active form of oxygen “charged” with energy from the photosensitiser.
Secondly, bacteriochlorins have a positive electric charge in a solution, which, according to recent studies, increases the effectiveness of photosensitisers against bacteria both in a free state and in biofilm form.