Work

Porphyrin Modifications for Enhanced Photodynamic Inactivation of Microbial Pathogens

Year: 2025

Type: article

Abstract: Significance Diseases caused by bacteria affecting the upper respiratory tract are a concern in the healthcare system, according to the World Health Organization. Multidrug-resistant Klebsiella pneumoniae is considered a critical pathogen due to its antibiotic resistance. Approach Photodynamic therapy (PDT) is a promising alternative, using photosensitizers (PSs) and light to generate reactive oxygen species for bacterial inactivation. This study evaluated porphyrin derivatives with different substituents against K. pneumoniae. The bacteria were incubated for 1h with different meso-substituted porphyrins (cationic, neutral, and negatively charged) in a range of concentrations. Samples were irradiated in the therapeutic window at different light doses. Treatments were evaluated by viability assay. Results Cationic imidazolyl-derived porphyrins achieved >3 log bacterial reductions under irradiation, and effectiveness depended on PS concentration and light dose. Conclusions Designed porphyrins show promise for K. pneumoniae PDT, supporting PDT as a non-antibiotic strategy against resistant infections. Understanding substituent effects aids the design of next-generation antimicrobial photosensitizers.

Source: Photodiagnosis and Photodynamic Therapy

DOI: 10.1016/j.pdpdt.2025.105116

Authors: Zoe Arnaut, Fernanda Alves, Mariette M. Pereira, Vanderlei S. Bagnato

Institutions: University of Coimbra, Universidade de São Paulo, Instituto de Física de São Carlos

Language: English

Topic: Photodynamic Therapy Research Studies

Subfield: Pulmonary and Respiratory Medicine

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $2,610