ABSTRACT
Photodynamic antimicrobial therapy (PACT) is an innovative approach to treating antimicrobial-resistant pathogens. The emergence of antimicrobial-resistant pathogens made the existing antibiotics less effective. This became a global burden, alarming mankind. The evolution of these organisms could potentially send us back to the pre-antibiotic era. PACT technique utilises a light source, photosensitiser, and molecular oxygen. When the appropriate wavelength of light is absorbed, the photosensitiser will be excited from the ground state to the higher state. The transfer of charge or energy elicits a biochemical reaction leading to the generation of ROS, increasing the oxidative stress in the cell which is not favourable to the pathogens. Various kinds of light sources, photosensitiser derivatives, and bioconjugate methods to produce ROS had been developed over the past few decades to improve the compatibility of PACT. Due to its ability to kill microbes covering the entire spectrum of antibiotics, PACT might be developed as a viable method to decrease antibiotic load across the globe. It is effective in killing bacteria, viruses, and other kinds of infections effectively without inducing the emergence of any kind of resistant pathogens. Hence, we hypothesise that antibiotics can be replaced by PACT technology in near future.
