Photo-Induced Destruction of Giant Vesicles in Methylene Blue Solutions

Caetano, Wilker; Haddad, Paula S.; Itri, Rosângela; Severino, Divinomar; Vieira, Vinícius C. C.; Baptista, Maurı́cio S.; Schröder, and André P.; Marques, Carlos M.

doi:10.1021/la061510v

Cited by 90 publications

(109 citation statements)

References 29 publications

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“…Thus, understanding the location of these drugs and their interactions with the cell membrane have become rather important parameters for the targeted design of drugs for photo-activated therapies. 7,8 The complexity of biological membranes makes direct studies very difficult; thus, simple model systems that can mimic the cellular environment, such as micelles and lipid vesicles, have been used. [9][10][11] Lipid vesicles are concentric uni-or multilamellar lipid bilayers that have layer diameters Vol.…”

Section: Introductionmentioning

confidence: 99%

Distribution of Xanthene Dyes in DPPC Vesicles: Rationally Accounting for Drug Partitioning Using a Membrane Model

Calori¹,

Pellosi²,

Vanzin³

et al. 2016

Journal of the Brazilian Chemical Society

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The correct selection of a dye that has effective action as a photosensitizer is a primary concern for successful therapeutic outcomes. The effectiveness of the photodynamic agent is related to both the targeting of cell membranes and the photochemical yield of the chosen dye. The distributions of xanthene derivatives Eosin Y, Erythrosin B, and Rose Bengal B in vesicles of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) in both liquid-crystalline and gel phases were investigated by fluorescence spectroscopy. Binding constants, fluorescence anisotropy, fluorescence quenching, fluorescence quantum yield, and fluorescence resonance energy transfer at physiological pH conditions were determined. To Erythrosin B and Eosin Y, the iodide quenching rate constant was shown to involve a sphere of action mechanism driven by a specific interaction between Erythrosin B and Eosin Y molecules and the choline head-group of the phospholipid; in contrast, Rose Bengal B was located deep in the membrane and this mechanism was not present. The dyes can be ordered by their penetration depth in the membrane, and this order was found to be Eosin Y < Erythrosin B < Rose Bengal B. These results demonstrate a rational approach for the screening of more active agents for photodynamic therapy based on the affinity between the xanthene derivatives and DPPC vesicles.

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Section: Introductionmentioning

confidence: 99%

Distribution of Xanthene Dyes in DPPC Vesicles: Rationally Accounting for Drug Partitioning Using a Membrane Model

Calori¹,

Pellosi²,

Vanzin³

et al. 2016

Journal of the Brazilian Chemical Society

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“…However, higher bacterial killing (2.0 log) was observed when PPIX-H 2 O 2 mixture was added to the bacterium followed by light irradiation. The enhanced bacterial killing of PPIX-H 2 O 2 mixture may be explained as suggested by Funk and Krise (2007) which reported that H 2 O 2 may alter the membrane permeability and hence the probability of cellular accumulation of the PS, or it may be due to the fact that the photoreaction would cause membrane disruption which in turn facilitate the penetration of H 2 O 2 into the cell (Caetano et al, 2007). Seaver and Imlay (2011) suggested that higher effect of PDT in the presence of H 2 O 2 could be because PS has an easier transit across the bacterial cell membrane, or the presence of H 2 O 2 may increase the amount of molecular oxygen which improves the ROS formation as suggested by Garcez et al (2011).…”

Section: Discussionmentioning

confidence: 94%

Influence of hydrogen peroxide or gold nanoparticles in protoporphyrin IX mediated antimicrobial photodynamic therapy on Staphylococcus aureus

Awad¹,

rasekaran²,

Shanmugam³

et al. 2013

Afr. J. Microbiol. Res.

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Antimicrobial photodynamic therapy (APDT) has been considered to treat skin diseases infected by drug resistant microorganisms. In this work, attempts were made to study the effectiveness of APDT with protoporphyrin IX (PPIX) in the presence of gold nanoparticles (GNPs) or hydrogen peroxide (H 2 O 2 ) against the human bacterial pathogen, Staphylococcus aureus. To photoactivate the PPIX, xenon light source was used at 626 nm. The bactericidal effect was analyzed by standard plate counting method. Attempts were also made to study whether fluorescence spectroscopy can be used to characterize the damage at protein level. Results of the study revealed that PPIX with H 2 O 2 has showed higher bactericidal effect than that of PPIX alone and PPIX with GNPs. From fluorescence spectroscopic characterization it was found that protein damage is one of the reasons of bactericidal effect as there is a considerable change in the intensity of emission and fluorescence lifetime of tryptophan present in the microorganism between pre and post APDT.

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“…[12] Recently, we have prepared fluid dimyristoylphosphatidylcholine (DMPC) bilayers on dithiothreitol (DTT) covered AuA C H T U N G T R E N N U N G (111) by vesicle fusion. [13] The OH-rich DTT monolayer turns the Au surface hydrophilic enough to allow vesicle fusion [14] as revealed by in situ atomic force imaging. Methylene blue (MB) and flavin adenine dinucleotide (FAD) have been used as probes to study molecule transport across the bilayer.…”

Section: Introductionmentioning

confidence: 99%

Phospholipid Bilayers Supported on Thiolate‐Covered Nanostructured Gold: In Situ Raman Spectroscopy and Electrochemistry of Redox Species

et al. 2009

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Thiol-covered nanostructured gold has been tested as a platform for the preparation of high-area phospholipid bilayer systems suitable for optical and electrochemical sensing. In situ and ex situ Raman spectroscopy and electrochemical measurements are made to study methylene blue (MB) and flavin-adenine dinucleotide (FAD) incorporation into dimyristoylphosphatidylcholine (DMPC) bilayers prepared by vesicle fusion on dithiothreitol (DTT)-covered nanostructured gold. Results show that lipophilic positively charged MB molecules are incorporated in the bilayer reaching the DTT-gold interface. On the other hand, the negatively charged FAD molecules are immobilized at the outer part of the phospholipid bilayer and cannot be electrochemically detected. Our results demonstrate that DTT-covered nanostructured gold provides a suitable high-area platform for phospholipid membranes that are able to separate and sense different kinds of molecules and biomolecules.

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Photo-Induced Destruction of Giant Vesicles in Methylene Blue Solutions

Cited by 90 publications

References 29 publications

Distribution of Xanthene Dyes in DPPC Vesicles: Rationally Accounting for Drug Partitioning Using a Membrane Model

Distribution of Xanthene Dyes in DPPC Vesicles: Rationally Accounting for Drug Partitioning Using a Membrane Model

Influence of hydrogen peroxide or gold nanoparticles in protoporphyrin IX mediated antimicrobial photodynamic therapy on Staphylococcus aureus

Phospholipid Bilayers Supported on Thiolate‐Covered Nanostructured Gold: In Situ Raman Spectroscopy and Electrochemistry of Redox Species

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