Russian researchers at Sechenov University have developed an enhanced photodynamic light therapy that accelerates the healing of infected skin wounds.
Working alongside international colleagues from China, the research team demonstrated in animal experiments that the modified treatment reduced inflammation and promoted rapid skin restoration in mice.
The university press service told news outlet Lenta.ru that the technique builds upon traditional photodynamic therapy. In standard photodynamic procedures, clinicians apply a light-sensitive compound to a wound before exposing the area to specific light wavelengths. This light exposure triggers the formation of reactive oxygen species that attack and destroy bacterial cells.
The reactive oxygen species generated during light activation break down bacterial cell membranes and intracellular components, preventing the pathogens from replicating. Photodynamic therapy has long served as an alternative light-based treatment in dermatology and oncology, offering a mechanism to combat localized bacterial infections without relying solely on conventional systemic antibiotics.
Polymer additives and photosensitizers
To enhance the effectiveness of the treatment, the Russian and Chinese researchers combined two light-sensitive substances: methylene blue and a chlorin e6 derivative. They fortified the solution with two specialized polymer components, Pluronic F108 and sodium alginate.
According to the research team, Pluronic F108 helps the light-sensitive molecules retain their activity and operate more effectively following light exposure. Meanwhile, the team noted that sodium alginate creates a favorable environment for damaged tissue recovery. Sodium alginate is a natural polysaccharide extracted from brown seaweeds, commonly used in modern medical wound dressings for its biocompatibility and moisture retention, while Pluronic F108 is a synthetic block copolymer surfactant used in pharmaceuticals to stabilize active molecules.
Methylene blue is a historic medical dye with proven antimicrobial properties when activated by light, whereas chlorin e6 derivatives are plant-based compounds known for absorbing light effectively in the red spectrum.
Animal trials and skin restoration
The scientists evaluated the enhanced method on laboratory mice with skin wounds infected by Staphylococcus aureus. The test animals received two sessions of photodynamic therapy and were monitored over a 13-day healing window.
When using the most effective formulation, infected wounds were virtually closed by the ninth day of observation, with combinations based on methylene blue delivering particularly strong results. Staphylococcus aureus is a bacterial strain frequently implicated in skin, soft tissue, and surgical site infections.
Detailed examination of the regenerated skin showed that the treatment significantly reduced localized inflammation while encouraging the development of mature connective tissue and properly arranged collagen fibers. Collagen is the primary structural protein found in extracellular connective tissues, providing tensile strength and flexibility during dermal repair.
New hair follicles also formed in the recovered skin tissue, confirming that the procedure restored normal anatomical skin structure rather than merely producing scar tissue.
Sechenov First Moscow State Medical University, established in 1758 in Moscow, is Russia's oldest medical school and leading health science research center.
