Photobiological characteristics of chlorophyll a derivatives as microbial PDT agents

Uliana, Marciana P.; Pires, Layla; Pratavieira, Sebastião; Brocksom, Timothy J.; Oliveira, Kléber T. de; Bagnato, Vanderlei Salvador; Kurachi, Cristina

doi:10.1039/c3pp50376c

Cited by 70 publications

(39 citation statements)

References 43 publications

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“…A stock solution of Chlorine e6 (synthesized at the Department of Chemistry of the Federal University of São Carlos) 25 was prepared using 1 mg of the PS in powder diluted in 1 μl dimethyl sulfoxide (DMSO; LabSynth ® Ltda, Diadema, SP, Brazil) and distilled water was added up to 1 ml, obtaining a 1 mg ml −1 solution. The animals were anesthetized using inhalation anesthesia (isoflurane, 2% in oxygen) and the hair of an area around the tumor about 2 cm in diameter was removed, then a dose of 2 mg kg −1 of chlorine e6 was injected via the tail vein with a 4 h druglight interval (DLI) according to the protocol.…”

Section: Procedures For In Vivo Measurementsmentioning

confidence: 99%

Photodynamic therapy dosimetry using multiexcitation multiemission wavelength: toward real-time prediction of treatment outcome

Mousavi

Moriyama²,

Grecco³

et al. 2020

J. Biomed. Opt.

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Engels, "Photodynamic therapy dosimetry using multiexcitation multiemission wavelength: toward real-time prediction of treatment outcome," J.Abstract. Evaluating the optical properties of biological tissues is needed to achieve accurate dosimetry during photodynamic therapy (PDT). Currently, accurate assessment of the photosensitizer (PS) concentration by fluorescence measurements during PDT is typically hindered by the lack of information about tissue optical properties. In the present work, a hand-held fiber-optic probe instrument monitoring fluorescence and reflectance is used for assessing blood volume, reduced scattering coefficient, and PS concentration facilitating accurate dosimetry for PDT. System validation was carried out on tissue phantoms using nonlinear least squares support machine regression analysis. It showed a high correlation coefficient (>0.99) in the prediction of the PS concentration upon a large variety of phantom optical properties. In vivo measurements were conducted in a PDT chlorine e6 dose escalating trial involving 36 male Swiss mice with Ehrlich solid tumors in which fluences of 5, 15, and 40 J cm −2 were delivered at two fluence rates (100 and 40 mW cm −2 ). Remarkably, quantitative measurement of fluorophore concentration was achieved in the in vivo experiment. Diffuse reflectance spectroscopy (DRS) system was also used to independently measure the physiological properties of the target tissues for result comparisons. Then, blood volume and scattering coefficient measured by the fiber-optic probe system were compared with the corresponding result measured by DRS and showed agreement. Additionally, tumor hemoglobin oxygen saturation was measured using the DRS system. Overall, the system is capable of assessing the implicit photodynamic dose to predict the PDT outcome. © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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Section: Procedures For In Vivo Measurementsmentioning

confidence: 99%

Photodynamic therapy dosimetry using multiexcitation multiemission wavelength: toward real-time prediction of treatment outcome

Mousavi

Moriyama²,

Grecco³

et al. 2020

J. Biomed. Opt.

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“…Chlorin-e6 (Ce6) and curcumin (CUR) were synthesized as described in the literature [32][33][34]. Methylene blue (MB) was obtained from Sigma (Sigma-Aldrich Co. LLC, St. Louis, MO, USA).…”

Section: Photosensitizers and Light Sourcesmentioning

confidence: 99%

Susceptibility of Enterococcus faecalis and Propionibacterium acnes to antimicrobial photodynamic therapy

Annunzio

Freitas

Blanco

et al. 2018

Journal of Photochemistry and Photobiology B: Biology

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Bacterial resistance to available antibiotics nowadays is a global threat leading researchers around the world to study new treatment modalities for infections. Antimicrobial photodynamic therapy (aPDT) has been considered an effective and promising therapeutic alternative in this scenario. Briefly, this therapy is based on the activation of a non-toxic photosensitizing agent, known as photosensitizer (PS), by light at a specific wavelength generating cytotoxic singlet oxygen and free radicals. Virtually all studies related to aPDT involve a huge screening to identify ideal PS concentration and light dose combinations, a laborious and time-consuming process that is hardly disclosed in the literature. Herein, we describe an antimicrobial Photodynamic Therapy (aPDT) study against Enterococcus faecalis and Propionibacterium acnes employing methylene blue, chlorin-e6 or curcumin as PS. Similarities and discrepancies between the two bacterial species were pointed out in an attempt to speed up and facilitate futures studies against those clinical relevant strains. Susceptibility tests were performed by the broth microdilution method. Our results demonstrate that aPDT mediated by the three above-mentioned PS was effective in eliminating both gram-positive bacteria, although P. acnes showed remarkably higher susceptibility to aPDT when compared to E. faecalis. PS uptake assays revealed that P. acnes is 80 times more efficient than E. faecalis in internalizing all three PS molecules. Our results evidence that the cell wall structure is not a limiting feature when predicting bacterial susceptibility to aPDT treatment.

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“…It exhibits no long term phototoxicity and is in advance clinical trials for numerous cancer indications. 160 In addition to PDT, efforts have been made to generate socalled "multi-modality" drugs both for tumor diagnosis and treatment or "theranostics". An enhanced localization of the PS in the tumor and similar PDT efficacy and phototoxicity compared to the free drug was observed in vivo.…”

Section: Chlorophylls In Medicinal Chemistrymentioning

confidence: 99%

How green is green chemistry? Chlorophylls as a bioresource from biorefineries and their commercial potential in medicine and photovoltaics

Ryan

Senge

2015

Photochem Photobiol Sci

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As the world strives to create a more sustainable environment, green chemistry has come to the fore in attempts to minimize the use of hazardous materials and shift the focus towards renewable sources. Chlorophylls, being the definitive "green" chemical are rarely used for such purposes and this article focuses on the exploitation of this natural resource, the current applications of chlorophylls and their derivatives whilst also providing a perspective on the commercial potential of large-scale isolation of these pigments from biomass for energy and medicinal applications.

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Photobiological characteristics of chlorophyll a derivatives as microbial PDT agents

Cited by 70 publications

References 43 publications

Photodynamic therapy dosimetry using multiexcitation multiemission wavelength: toward real-time prediction of treatment outcome

Photodynamic therapy dosimetry using multiexcitation multiemission wavelength: toward real-time prediction of treatment outcome

Susceptibility of Enterococcus faecalis and Propionibacterium acnes to antimicrobial photodynamic therapy

How green is green chemistry? Chlorophylls as a bioresource from biorefineries and their commercial potential in medicine and photovoltaics

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