Cationic heme-mimetic gallium porphyrin photosensitizer for combating ESKAPE biofilms

The escalating problem of antibiotic resistance in pathogenic bacteria poses a significant challenge to modern medicine, prompting the pursuit of innovative therapeutic solutions. One promising strategy is antimicrobial photodynamic inactivation using heme-mimetic gallium porphyrins. Despite its potential, the combination of gallium porphyrins and light as a powerful antimicrobial approach, especially for targeting biofilms, remains largely underexplored. In this study, we demonstrate that iron-blocking therapy with a newly synthesized cationic heme-mimetic gallium porphyrin (GaCHP-2-3), when activated by light, effectively disrupts bacterial biofilms formed under stationary and flow conditions, including those on titanium dental implants. Importantly, unlike antibiotics, bacteria were unable to develop resistance to GaCHP-2-3 aPDI treatment. This work highlights the potential of GaCHP-2-3 to enhance the efficacy of antibiofilm treatments and combat antibiotic-resistant infections. The work was supported from the National Science Centre in Poland (grant no. 2018/30/Q/NZ7/00281).