Treatment of pulmonary complications from the coronavirus, COVID-19, is an urgent unresolved medical problem. The virus is highly contagious and there is no vaccine. There is also no really effective and affordable antiviral drug yet. Severe and life-threatening complications, including coronavirus pneumonia, are common. The daily increase in the number of viral pneumonia victims during the coronavirus pandemic has inspired scientists around the world to search for new methods of antiviral (etiotropic) therapeutic treatments.
NSU Professor Sergei Nikonov, Head of the Laboratory for Biomedical Applications of Quantum Materials, Devices, and Systems, proposed a fundamentally new concept for inactivation of viral pathogens using photodynamic therapy (PDT).
Photodynamic therapy is a non-aggressive (organ-sparing) method of treating some forms of malignant neoplasms, precancerous diseases of the female genital area, as well as chronic inflammatory diseases of the upper respiratory tract, acne, and viral warts. In Russia, photodynamic therapy for some oncological diseases is a high-tech treatment supported by the government. In the modern era, there is a new threat to humanity from the world of bacteria. There has been an increase in the incidence of infections that do not respond to antibiotics due to the development of microbial resistance to the drugs. In response to this challenge, alternatives to antibiotics are being developed, including antimicrobial photodynamic therapy (PDT).
PDT is based on a photochemical reaction in which light energy interacts with a photosensitive substance introduced into the patient's body. Medicinal photosensitizers are chemical compounds of natural and artificial origin. With a quanta of visible light they pass into an excited (triplet) state and upon return to a stable state, they transfer the received energy to oxygen molecules that dissolve in tissues converting it into toxic radicals. These oxygen radicals are capable of killing cancer cells and bacteria and causing irreversible damage to viral envelopes and their genetic material. After photodynamic inactivation, the multiplication of viruses in the victim's body stops and recovery begins.
To date, the scientific literature provides convincing evidence that the photodynamic inactivation of enveloped and non-enveloped RNA and DNA viruses can be successfully implemented using photosensitizers such as methylene blue, psoralen, or chlorin E6 and light energy corresponding to the absorption spectrum of the photosensitizer. Among all known methods, methylene blue and visible light have been scientifically proven the most effective for inactivation of both enveloped and non-enveloped viruses.
Professor Nikonov described this preventive approach in the fight against coronavirus infection,
To weaken the epidemic, it is important not only to learn how to destroy the virus using PDT, but also to make the entrance gate, the mucous membrane of the respiratory tract, impenetrable for viral infection. It is in the mucous membrane cells that angiotensin-converting enzyme proteins contain molecules that anchor the viral corona to themselves. After attachment, the virus enters the cells and begins disease-causing reproduction. With the help of a photosensitizer applied to the mucous membranes of the upper respiratory tract and a stream of light it is possible to inactivate this enzyme and prevent the attachment of the virus and thus prevent the disease.
A laser PDT method for inactivation of coronaviruses using domestic photosensitizers traditionally used in oncology and some dyes known in medicine was developed and studied to confirm the hypothesis of anticancer photodynamic therapy,. Scientists-virologists at "Vector" discovered new antiviral properties of the domestic drug "Radachlorin". It is registered as a drug for anti-tumor photodynamic therapy and demonstrated the anti-COVID effects of using the world famous methylene blue.
The satisfying results of the study include that the virus can be destroyed in 40 seconds using a low-power laser energy stream and negligible amounts of drug photosensitizers. Researchers were able to not only inactivate the SARS-CoV-2 viral suspension by the photodynamic method, but also to prove that cell cultures infected with SARS-CoV-2 virus are cured by PDT.
The discovery of the high antiviral activity of the pharmacopoeial drugs methylene blue and "Radachlorin" for PDT allows scientists to recommend them for use in clinical practice for the prevention and treatment of COVID-19.
