Phthalocyanine photosensitizers in antimicrobial photodynamic therapy as a multifunctional strategy for combating antimicrobial resistance.
6 affiliations
- 1Department of Chemistry, School of Science and Technology, The University of Georgia, Merab Kostava str. 77a, Tbilisi, 0171, Georgia. [email protected].
- 2Laser Research Centre, Faculty of Health Sciences, University of Johannesburg, Doornfontein, 17011, 2028, South Africa.
- 3Department of Chemistry, School of Science and Technology, The University of Georgia, Merab Kostava str. 77a, Tbilisi, 0171, Georgia.
- 4Department of Chemistry, Yildiz Technical University, Davutpaşa Caddesi, Istanbul, 34220, Turkey.
- 5R. Agladze Inorganic chemistry and electrochemistry Institute, Ivane Javakhishvili Tbilisi State University, Rapiel Mindeli str. 3, Tbilisi, Georgia.
- 6Laser Research Centre, Faculty of Health Sciences, University of Johannesburg, Doornfontein, 17011, 2028, South Africa. [email protected].
Abstract
With antimicrobial resistance (AMR) on the rise, there is an urgent need for non-antibiotic approaches to treatment. Antimicrobial photodynamic therapy (aPDT) is being investigated as a non-antibiotic strategy for treating infections caused by multidrug-resistant (MDR) organisms. In this review we offer a thorough examination of phthalocyanines (Pcs) and metallophthalocyanines (MPcs), second-generation photosensitizers investigated mainly for bacterial and fungal photoinactivation. Antiviral aPDT is discussed separately because Pc-specific antiviral evidence remains comparatively limited. Our analysis focuses on how central-metal electronic configuration, spin–orbit coupling, and peripheral substitution influence intersystem crossing, triplet-state formation, and reactive oxygen species (ROS) generation in metallophthalocyanines. We also consider the physicochemical constraints that come with these compounds, namely their tendency to undergo aggregation-induced quenching (AIQ) in aqueous solution. To counter this and to get past the outer membrane of Gram-negative species, we evaluate synthetic changes such as cationic peripheral functionalization. The paper further explores how Pcs are being combined with pharmaceutical nanotechnology – be it liposomes, metallic nanoparticles or graphene oxide – to improve bioavailability and open the door to synergistic photothermal therapy (PTT). The promise of Pc-conjugates linked to bioactive agents like antibiotics is likewise noted. Yet for all the in vitro and preclinical data accumulated over the years, phthalocyanine-based aPDT has seen little use in the clinic. We close with an appraisal of the reasons for this shortfall, from issues of dosimetry and localized hypoxia to difficulties in penetrating biofilms, and put forward the case for engineering stimulus-responsive nanoplatforms as a way to bridge the regulatory and biological divide.
Graphical Abstract: Near-infrared light photoexcites nano-encapsulated metal phthalocyanines, or MPcs. Non-radiative decay leads to photothermal therapy and thermal damage to a target cell. A second pathway involves tissue oxygen and reactive oxygen species generation, leading to photodynamic therapy and oxidative damage. The substituted MPc structure is also shown.
Related
- Introducing 2-Thioxocoumarins as a New Class of Photosensitizers for Antimicrobial Photodynamic Therapy
- Highly Stable PLA/Gelatin Bionanocomposites for Enhanced Delivery of Chloroaluminum Phthalocyanine for Photodynamic Therapy against SK-MEL-28 Cells
- Artificial Intelligence in Photodynamic Therapy: From Molecular Design of Photosensitizers to Intelligent Delivery, Adaptive Dosimetry, and Personalized Prognostication of Results
- Antimicrobial Effect of Potassium Iodide Combined with Methylene Blue-Mediated Photodynamic Therapy on Cultured Subgingival Plaque-Derived Polymicrobial Suspensions.
- Evaluating the Antimicrobial Activity of Curcumin-loaded Lipid Nanocarriers When Applying Photodynamic and Sonodynamic Therapy for the Treatment of Skin Infections
BibTeX
@article{arabuli2026phthalocyanine,
title = {{Phthalocyanine photosensitizers in antimicrobial photodynamic therapy as a multifunctional strategy for combating antimicrobial resistance.}},
author = {Lili Arabuli and Mehak Zahra and Dimitri Lashkhi and Mevlude Canlica and Nana Tsiklauri and Bahadir Keskin and Rusudan Gigauri and Anine Crous and Heidi Abrahamse and Blassan George},
journal = {Discover nano},
year = {2026},
month = nov,
doi = {10.1186/s11671-026-05103-6},
url = {https://europepmc.org/article/MED/42970232},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Phthalocyanine photosensitizers in antimicrobial photodynamic therapy as a multifunctional strategy for combating antimicrobial resistance.
AU - Lili Arabuli
AU - Mehak Zahra
AU - Dimitri Lashkhi
AU - Mevlude Canlica
AU - Nana Tsiklauri
AU - Bahadir Keskin
AU - Rusudan Gigauri
AU - Anine Crous
AU - Heidi Abrahamse
AU - Blassan George
PY - 2026
DA - 2026/11/02
JO - Discover nano
DO - 10.1186/s11671-026-05103-6
UR - https://europepmc.org/article/MED/42970232
AB - With antimicrobial resistance (AMR) on the rise, there is an urgent need for non-antibiotic approaches to treatment. Antimicrobial photodynamic therapy (aPDT) is being investigated as a non-antibiotic strategy for treating infections caused by multidrug-resistant (MDR) organisms. In this review we offer a thorough examination of phthalocyanines (Pcs) and metallophthalocyanines (MPcs), second-generation photosensitizers investigated mainly for bacterial and fungal photoinactivation. Antiviral aPDT is discussed separately because Pc-specific antiviral evidence remains comparatively limited. Our analysis focuses on how central-metal electronic configuration, spin–orbit coupling, and peripheral substitution influence intersystem crossing, triplet-state formation, and reactive oxygen species (ROS) generation in metallophthalocyanines. We also consider the physicochemical constraints that come with these compounds, namely their tendency to undergo aggregation-induced quenching (AIQ) in aqueous solution. To counter this and to get past the outer membrane of Gram-negative species, we evaluate synthetic changes such as cationic peripheral functionalization. The paper further explores how Pcs are being combined with pharmaceutical nanotechnology – be it liposomes, metallic nanoparticles or graphene oxide – to improve bioavailability and open the door to synergistic photothermal therapy (PTT). The promise of Pc-conjugates linked to bioactive agents like antibiotics is likewise noted. Yet for all the in vitro and preclinical data accumulated over the years, phthalocyanine-based aPDT has seen little use in the clinic. We close with an appraisal of the reasons for this shortfall, from issues of dosimetry and localized hypoxia to difficulties in penetrating biofilms, and put forward the case for engineering stimulus-responsive nanoplatforms as a way to bridge the regulatory and biological divide. Graphical Abstract: Near-infrared light photoexcites nano-encapsulated metal phthalocyanines, or MPcs. Non-radiative decay leads to photothermal therapy and thermal damage to a target cell. A second pathway involves tissue oxygen and reactive oxygen species generation, leading to photodynamic therapy and oxidative damage. The substituted MPc structure is also shown.
SN - 2731-9229
ER -