In antibacterial photodynamic therapy, irradiation is used to produce reactive oxygen species that kill off bacteria. Because it requires external light and oxygen, this method is only suitable for surface infections.
In the journal Angewandte Chemie, a Chinese research team has now introduced a molecular “singlet oxygen battery” that can be “charged” with reactive oxygen, which it then releases in deep tissue layers to target methicillin-resistant staphylococcus.
Antibiotic-resistant bacteria are on the rise. Though often harmless to healthy people, dreaded multidrug-resistant “hospital pathogens” such as methicillin-resistant Staphylococcus aureus (MRSA) use injuries or fresh surgical wounds to gain entry to the body. They also infect immunocompromised patients. Because antibiotics are not effective, there is sometimes no remedy.
One highly promising alternative is antibacterial photodynamic therapy, which is already widely used in dentistry. In this technique, a light-activated substance (photosensitizer) is irradiated, triggering a photodynamic reaction that produces singlet oxygen (1O2), an excited form of oxygen.
Unlike antibiotics, this substance simultaneously attacks multiple biomolecular sites on the bacteria. It is easy to use, safe, painless, and generally free of side effects. Unfortunately, it has only been useful for surface infections because the necessary light only penetrates a few millimeters into the tissue. Additionally, deeper tissue layers also do not have enough oxygen for effective treatment.
2023-08-16 10:00:04
Article from phys.org