Photodynamic effect of novel hexa-iodinated quinono-cyanine dye on Staphylococcus aureus.
Photodiagnosis Photodyn Ther 2020;
31:101866. [PMID:
32534248 DOI:
10.1016/j.pdpdt.2020.101866]
[Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/26/2020] [Accepted: 06/05/2020] [Indexed: 01/11/2023]
Abstract
BACKGROUND
Staphylococcus aureus (S. aureus) is a Gram-positive bacteria and major human pathogen which can cause a wide variety of serious infections when it enters the bloodstream or internal tissues. Antimicrobial photodynamic therapy (APDT) utilizing a light-activated dye (photosensitizer) is a powerful method for in vitro and in vivo eradication of S. aureus and other pathogenic bacteria. However, the development of highly efficient, long-wavelength photosensitizers showing high phototoxicity to pathogens and low dark toxicity is still challenging.
AIM
To develop a highly efficient, long-wavelength photosensitizer for photodynamic inactivation of S. aureus.
METHOD
Synthesis of the new photosensitizer, hexa-iodinated quinono-cyanine dye IQCy and investigation of the dark and light-induced toxicity of this dye compared to known photosensitizers Chlorin e6 (Ce6) and HITC towards S. aureus.
RESULTS
When exposed to 14.9 J/cm2 white LED light, 0.5 μM of IQCy, Ce6 and HITC inactivate, respectively, 99 %, 40 % and 30 % of S. aureus and at 0.05 μM and 27.9 J/cm2 - 71 %, 18 % and 9%, which is much better compared to Ce6 and HITC. IQCy exhibits no dark toxicity at least at 10 μM dye concentration.
CONCLUSIONS
IQCy demonstrates a more pronounced photodynamic inactivation of S. aureus as compared to Ce6 and HITC and can be employed for the eradication of these bacteria at lower concentration and reduced light dose.
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