Multicationic ruthenium phthalocyanines as photosensitizers for photodynamic inactivation of multiresistant microbes
Year: 2024
Type: article
Abstract: Four photosensitizers PS1a-PS4a consisting in multicationic ruthenium(II) phthalocyanines (RuPcs) have been evaluated in photodynamic inactivation (PDI) of multiresistant microorganisms. The RuPcs, bearing from 4 to 12 terminal ammonium salts, have been designed to target the microorganisms cytoplasmic cell membrane and display high singlet oxygen quantum yields. In addition, PS3a and PS4a were conceived to exhibit multi-target localization by endowing them with amphiphilic character, using two different structural approaches. Under low light regimes, the two hydrophilic PS1a and PS2a , as well as the amphiphilic PS3a show much stronger response against Gram-positive MRSA than that observed for the typical phthalocyanines designed for PDI, namely zinc(II) and palladium(II) complexes, as well as free-base Pcs. Besides, PS1a , PS2a and PS3a show remarkably high activity against the Gram-negative E. coli , although weak fungicidal character against fluconazole-resistant C. albicans . Contrasting, the structurally different, amphiphilic PS4a shows only slight activity for Gram-positive bacteria, despite its ability to cross cell membrane and reach internal organelles. Still, PS4a shows a positive synergistic effect against MRSA when combined with doxycycline, exhibiting an increased activity from about 1.5 to about 4.9 log reduction under the light dose of 30 J/cm 2 and the 0.125 mg/L subinhibitory dose of doxycycline. • Ruthenium Phthalocyanines show strong PDI response against multiresistant bacteria. • Multicationic PS1a , PS2a , PS3a RuPcs outperform other MPcs against MRSA and E. coli • Synergic activity with doxycycline enhances PS4a ′s limited PDI effect. • PS1a, PS2a, PS3a RuPcs show 5 log reduction in bacterial growth with low light dose.
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $4,850
Awards: G103507813, G1105844351, G1175115578, G1287533594, G1446647517, G1455481585, G1809131675, G190113283, G1971932983, G2262748287, G2380629619, G2601397997, G300979063, G3480869486, G3681454997, G4042783231, G425668148, G4278938174, G4655133251, G4717959651, G491712853, G5080475149, G5195188938, G5209569390, G5333184521, G586857820, G6731524417, G7084143925, G744962750, G7805626310, G7863371703, G8497050386, G982922924
OpenAlex ID: W4405825794