Photodynamic Antimicrobial Chemotherapy: Advancements in Porphyrin-Based Photosensitize Development

Abstract

The reduction of available drugs with effectiveness against microbes is worsening with the current global crisis of antimicrobial resistance. This calls for innovative strategies for combating antimicrobial resistance. Photodynamic Antimicrobial Chemotherapy (PACT) is a relatively new method that utilizes the combined action of light, oxygen, and a photosensitizer to bring about the destruction of microorganisms. This technique has been found to be effective against a wide spectrum of microorganisms, including bacteria, viruses, and fungi. Of greater interest is their ability to destroy resistant strains of microorganisms and in effect help in combating the emergence of antimicrobial resistance. This manuscript reviews porphyrins and porphyrin-type photosensitizers that have been studied in the recent past with a focus on their structure-activity relationship.

Photodynamic Therapy for the Treatment and Diagnosis of Cancer–A Review of the Current Clinical Status

“…Indeed, Hermann von Tappeiner coined the term "photodynamic reaction", underlining the fact that light played an important role (v. Tappeiner, 1909;Niculescu and Grumezescu, 2021). PDT of infections, which involves reactive oxygen species (ROS) to disrupt and kill microbes, can be useful against bacteria and viruses ( Hamblin and Hasan, 2004;Jori, 2006;Oyim et al, 2021;Rapacka-Zdonczyk et al, 2021;Warrier et al, 2021). Due to the World Wars, the evolution of the idea has been delayed for nearly 60 years.…”

Progress in Alternative Strategies to Combat Antimicrobial Resistance: Focus on Antibiotics

“…Photoinactivation or photodynamic antimicrobial chemotherapy (PACT) is a promising strategy to eliminate pathogenic bacteria, which utilizes visible light, a photosensitizer (PS)-chromophore, and molecular oxygen to create reactive oxygen species (ROS), resulting in bacterial cell death [ 315 , 316 ]. PACT has been demonstrated to act on a wide range of bacteria, i.e., Gram-negative and Gram-positive, antibiotic-resistant, or susceptible bacteria strains [ 315 ]. This technique has gained much research attention as an alternative strategy to combat AMR [ 317 , 318 ].…”

“…Several improvements have been made to position PACT as an effective alternative to antimicrobial chemotherapy, for example. Antimicrobial inactivation is the conjugation of porphyrins to nanoparticles [ 315 ]. By taking advantage of the small size of the porphyrins and porphyrin-nanoparticle conjugates, the photosensitizers can attach to the bacterial cell wall through a self-assembly process, resulting in cell deaths [ 315 ].…”

“…It is pertinent to improve the application of PACT in dermatological and control of infectious diseases, especially in the management of acne and skin infections in general. Given the wide range of bacteria, it has been noted that the potential application of PACT in the treatment of infectious diseases is still lagging [ 315 ]. While the application of the PACT systems has been extensively evaluated for the topical/local approach for animal model evaluations, more studies on systemic application still need to be done to fully evaluate their in vivo stability and therapeutic modality.…”

“…Notably, most studies lacked toxicity data, and there is a need, therefore, for future studies to include toxicity studies. Toxicity profile evaluation will be important in providing confidence in PACT systems before submitting the final products for regulatory endorsements [ 315 ].…”