Photoantimicrobial application in biomedical field: Whether new arrival or renewal of ancient chemical

Abstract

Despite the fact that infectious disease associated mortality has declined yet in the 21st century infectious diseases continue to be a threat to man and animals. A two-stage treatment module that involves light-sensitive chemicals and a light source to destroy microbes or abnormal cells are known as photodynamic therapy. On their own the chemicals and light source are harmless, but once a chemical is exposed to light, it is excited and produces reactive free radicals that damage the microbes. This technique may be used as a supplement to conventional antibiotics so that reduction in antibiotic consumption on earth may be curtailed to certain extent. At present the human population are surviving in the resistance era; drug resistance is inevitable. It is not a question of if but rather when. Genuine progress to achieve “right drug for right bug” has not yet been achieved. Expert groups across the globe are advocating for either reducing the antibiotic dose or to replace it with alternative medicine. The potentially lethal chemical weapons ultimately released from the activation of photosensitizers to destroy the pathogens are reactive oxygen species. Due to irreversible damage of the microbial proteins and nucleic acids, photoantimicrobial agents are not single-target specific. It is very unlikely that the microbes can develop resistance against the photoantimicrobials. However, the potential for microbial resistance development using photodynamic therapy (PDT) remains under investigation. We may not replace antibiotics but we may reduce it by PDT. Further detail is elaborated.