Resistance to antimicrobial agents is emerging in a wide variety of nosocomial and community-acquired pathogens. The development of alternative therapies against nosocomial infections caused by clinically relevant pathogens represents a major public health concern. RLP068/Cl is a novel Zn(II) phthalocyanine proposed as a photosensitizer suitable for antimicrobial photodynamic therapy (APDT) for localized infections. Its ability, following activation by light, to induce resistance in three major human pathogens after 20 daily passages was studied. Simultaneously for the same strains, the ability of daily sequential subcultures in subinhibitory concentrations of RLP068/Cl to develop resistant mutants without illumination was evaluated. We demonstrate that 20 consecutive APDT treatments with RLP068/Cl did not result in any resistant mutants and that, in dark conditions, only Staphylococcus aureus strains had increased MICs of RLP068/Cl. However, even in this case, the susceptibility of the mutated bacteria to APDT was not affected by their MIC increase.
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http://dx.doi.org/10.1128/AAC.00603-09 | DOI Listing |
Turk J Chem
October 2024
Department of Chemical Engineering, Faculty of Engineering and Natural Sciences, Uşak University, Uşak, Turkiye.
A new nonperipheral zinc(II) phthalocyanine bearing octa carboxylic acid ethyl ester derivative substituted triazole attached propylmercaptothiobenzylmercapto derivative was synthesized via the tetramerization reaction of phthalonitrile. The photochemical in vitro photodynamic activity of zinc(II) phthalocyanine (), such as human nonsmall cell lung carcinoma cell lines, was investigated in this study. The singlet oxygen generation property of novel zinc(II) phthalocyanine () was also examined due to the significantly high singlet oxygen quantum yield of (F = 0.
View Article and Find Full Text PDFViruses
December 2024
Institute of Experimental Morphology, Pathology and Anthropology with Museum, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria.
Photodynamic inactivation (PDI) has been revealed as a valuable approach against viral infections because of the fast therapeutic effect and low possibility of resistance development. The photodynamic inhibition of the infectivity of human herpes simplex virus type 1 (HSV-1) strain Victoria at different stages of its reproduction was studied. PDI activity was determined on extracellular virions, on the stage of their adsorption to the Madin-Darby bovine kidney (MDBK) cell line and inhibition of the viral replication stage by application of two tetra-methylpyridiloxy substituted gallium and zinc phthalocyanines (ZnPcMe and GaPcMe) upon 660 nm light exposure with a light-emitting diode (LED 660 nm).
View Article and Find Full Text PDFACS Sens
December 2024
Tor Vergata University of Rome, Department of Chemical Sciences and Technologies, Rome 00133, Italy.
A consistent part of gas sensor research activities aims to improve sensing performances by synthesizing new sensing materials, improving the selection of elements in arrays, and optimizing the feature extraction and classification algorithms. This paper combines most of these aspects to confer selectivity to a low-selectivity sensor by using feature extraction algorithms applied to the sensor response kinetics. Several algorithms were employed to represent the kinetic behavior of the sensor response during the adsorption and desorption phases.
View Article and Find Full Text PDFChembiochem
September 2024
Department of Chemistry, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki, Japan.
Water-soluble phthalocyanine (Pc) derivatives have been regarded as potential G-quadruplex (G4) nucleic acid-targeting ligands for anticancer therapy and have been extensively studied as effective photosensitizers for photodynamic therapy (PDT). Understanding how photosensitizers interact with nucleic acids and the subsequent photolytic reactions is essential for deciphering the initial steps of PDT, thereby aiding in the development of new photosensitizing agents. In this study, we found that red-light irradiation of a mixture of a Zn(II) Pc derivative and an all-parallel G4 DNA leads to catalytic and selective photodegradation of the DNA by reactive oxygen species (ROS) generated from the Zn(II) Pc derivative bound to DNA through a reaction mechanism similar to that of an enzyme reaction.
View Article and Find Full Text PDFDalton Trans
July 2024
Karadeniz Technical University, Macka Vocational School, Trabzon, Türkiye.
In this study, 2(3),9(10),16(17),23(24)-tetrakis-[(-methyl-(1-benzylpiperidin-4-yl)oxy)phthalocyaninato]zinc(II) iodide (ZnPc-2) was synthesized and characterized using spectral methods (FT-IR, H-NMR, UV-Vis and mass spectroscopy). The interaction of ZnPc-2 with DNA was investigated by using the UV/Vis titrimetric method, thermal denaturation profile, agarose gel electrophoresis and molecular docking studies. Additionally, the antidiabetic activity of ZnPc-2 was revealed spectroscopically by studying α-amylase and α-glucosidase inhibition activities.
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