Amphiphilic cationic Zn-porphyrins with high photodynamic antimicrobial activity

Document Type

Article

Abstract

Aim: Photodynamic inactivation of microbes can efficiently eradicate antibiotic-resistant strains. Systematic structural modification was used to investigate how porphyrin-based photosensitizers (PSs) could be designed for improved antibacterial activity. Materials & methods: Zinc(II)5,10,15,20-tetrakis(N-alkylpyridinium-2(3,4)-yl)porphyrins presenting systematic modifications at the periphery of the porphyrin ring were evaluated for toxicity and antimicrobial photodynamic activity by measuring metabolic activity, cell membrane integrity and viability using antibiotic-sensitive and resistant Escherichia coli strains as model Gram-negative targets. Results: Maximal sensitizer uptake, and, upon illumination, decrease of viable bacteria by >6 log10 were achieved by positively charged amphiphilic PSs with longer (six to eight carbon) alkyl substituents. Conclusion: Antibacterial photoefficiency (throughout the text photoefficiency has been used as equivalent of photocytotoxic efficacy) can be increased by orders of magnitude by increasing the lipophilicity of cationic alkylmetalloporphyrin PSs.

Keywords

antimicrobial photodynamic therapy, photosensitizer, porphyrin, reactive oxygen species, singlet oxygen

Publication Date

5-1-2015

Publication Title

Future Microbiology

ISSN

17460913

E-ISSN

17460921

Volume

10

Issue

5

First Page

709

Last Page

724

PubMed ID

26000647

Digital Object Identifier (DOI)

10.2217/fmb.14.148

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