New insights in photodynamic theraphy: production, diffusion and reactivity of singlet oxygen in biological systems

S'ha estudiat la cinètica de fotosensibilització de l'oxigen singlet (1O2) en cèl·lules eucariotes en suspensió mitjançant un espectròmetre d'última generació amb resolució temporal per sota del microsegon. Els estudis revelen que la cinètica del 1O2 depèn del seu lloc de formació. Per una banda, la producció del 1O2 es més lenta en els lisosomes que en el nucli. Per altra banda, el 1O2 es capaç d'escapar de les cèl·lules quan es fotosensibilitza en el nucli, però es queda confinat al interior si es fotosensibilitza en els lisosomes. Malgrat que el temps de vida del 1O2 es troba en els microsegons, la desactivació principal ve donada per interaccions amb les biomolècules característiques de cadascú dels orgànuls. La incertesa respecte a la producció de 1O2 en un orgànul determinat es pot eliminar mitjançant l'ús de fotosensibilitzadors modificats genèticament, ja que aquets poden ésser expressats selectivament. Amb aquesta finalitat, s'avaluen les propietats fotosensibilitzants de mutants de proteïna fluorescent verd (GFP). Algunes de les GFPs estudiades sensibilitzen la formació del 1O2 malgrat amb baixa eficiència. Els resultats obtinguts es comparen amb els del cromòfor de la GFP i mostren que l'estructura proteínica, a sobre de modular les propietats fotofísiques del cromòfor, també el protegeix de la desactivació col·lisional. Finalment, s'estudien les propietats d'absorció bifotónica del 2,7,12,17-tetrafenilporficé i del seu complex de pal·ladi (II). L'eficiència de formació del 1O2 per part dels dos compostos, desprès de l'absorció simultània de dos fotons, es aproximadament 100 vegades superior a la dels seus anàlegs porfirínics, amb seccions d'absorció bifotòniques δ ~ 25 GM. Les excel·lents propietats d'aquestos compostos s'expliquen mitjançant arguments qualitatius i s'analitzen les seves perspectives de cara al seu ús en teràpia fotodinámica.Se ha estudiado la cinética de fotosensibilización de 1O2 en células eucariotas en suspensión, usando un espectrómetro de última generación con resolución temporal por debajo del microsegundo. Los estudios revelan que la cinética del 1O2 depende de su lugar de formación. Por una parte, la producción de 1O2 es más lenta en los lisosomas que en el núcleo. Por otra parte, el 1O2 es capaz de escapar de las células cuando es fotosensibilizado en el núcleo, mientras que queda confinado en el interior si se fotosensibiliza en los lisosomas. A pesar de que el tiempo de vida del 1O2 se encuentra en los microsegundos, la desactivación principal viene dada por interacciones con las biomoléculas características de cada orgánulo. La incertidumbre respecto a la producción de 1O2 en un orgánulo determinado puede ser eliminada mediante el uso de fotosensibilizadores modificados genéticamente ya que pueden ser expresados selectivamente. Con este fin, se evalúan las propiedades fotosensibilizantes de mutantes de proteína fluorescente verde (GFP). Algunas de las GFPs estudiadas sensibilizan la formación de 1O2 aunque con baja eficiencia. Los resultados obtenidos se comparan con los del cromóforo de la GFP y muestran que la estructura proteínica, además de modular las propiedades fotofísicas del cromofóro, también lo protege de la desactivación colisional. Finalmente, se estudian las propiedades de absorción bifotónica del 2,7,12,17-tetrafenilporficeno y de su complejo de paladio (II). La eficacia de formación de 1O2 de ambos compuestos, tras la absorción simultánea de dos fotones, es aproximadamente 100 veces superior a la de sus análogos porfirínicos, con secciones de absorción bifotónica δ ~ 25 GM. Las excelentes propiedades de estos compuestos se explican mediante argumentos cualitativos y se analizan sus perspectivas de cara a su uso en terapia fotodinámica.The kinetics of singlet oxygen (1O2) photosensitisation in human skin fibroblasts have been investigated by means of an ultrasensitive near-infrared spectrometer with submicrosecond time resolution. The results indicate that the 1O2 kinetics are site-dependent. On one hand, the production of 1O2 is slower in the lysosomes than in the nucleus. On the other hand, 1O2 is able to escape out of the cells when photosensitised in the nucleus, while 1O2 photosensitized in the lysosomes is confined. Despite showing a lifetime in the microsecond time domain, the decay of 1O2 is governed by interactions with the biomolecules within the organelle there it is produced. The uncertainty as to the intracellular site of 1O2 production may be removed by the use of genetically-encoded photosensitisers, which can be expressed in any desired organelle. Towards this end, the ability of some fluorescent proteins (GFPs) to photosensitise 1O2 has been studied. Some of the studied proteins are able to produce 1O2 albeit with a very low quantum yield. The results obtained are compared to those of the synthetic GFP chromophore and indicates that the protein scaffold not only plays a role in modulating the photophysical properties of the chromophore but also has a protective function from collisional quenching. Finally, the two-photon absorption properties of tetraphenylporphycene and its palladium (II) complex have been determined. These compounds are ca. 100-fold more efficient two-photon 1O2 photosensitisers than their isomeric porphyrin counterparts, with two-photon absorption cross sections δ ~ 25 GM. Qualitative symmetry-based arguments are provided to explain the excellent two-photon properties and the prospects for photodynamic therapy are discussed

Towards an in-plane methodology to track breast lesions using mammograms and patient-specific finite-element simulations

In breast cancer screening or diagnosis, it is usual to combine different images in order to locate a lesion as accurately as possible. These images are generated using a single or several imaging techniques. As x-ray-based mammography is widely used, a breast lesion is located in the same plane of the image (mammogram), but tracking it across mammograms corresponding to different views is a challenging task for medical physicians. Accordingly, simulation tools and methodologies that use patient-specific numerical models can facilitate the task of fusing information from different images. Additionally, these tools need to be as straightforward as possible to facilitate their translation to the clinical area. This paper presents a patient-specific, finite-element-based and semi-automated simulation methodology to track breast lesions across mammograms. A realistic three-dimensional computer model of a patient''s breast was generated from magnetic resonance imaging to simulate mammographic compressions in cranio-caudal (CC, head-to-toe) and medio-lateral oblique (MLO, shoulder-to-opposite hip) directions. For each compression being simulated, a virtual mammogram was obtained and posteriorly superimposed to the corresponding real mammogram, by sharing the nipple as a common feature. Two-dimensional rigid-body transformations were applied, and the error distance measured between the centroids of the tumors previously located on each image was 3.84 mm and 2.41 mm for CC and MLO compression, respectively. Considering that the scope of this work is to conceive a methodology translatable to clinical practice, the results indicate that it could be helpful in supporting the tracking of breast lesions

La prefabricación estructural de la madera contralaminada y su aplicación en obra nueva y rehabilitación

La prefabricación estructural de la madera contralaminada y su aplicación en obra nueva y rehabilitación. La siguiente memoria, resumen del Trabajo Fin de Grado titulado del mismo modo, contiene una breve exposición de las posibilidades y cualidades de la madera contralaminada dentro del mundo de la arquitectura. Partiendo de una recopilación de características y aplicaciones de este versátil material, con su correspondiente valoración cualitativa; se pasa a un análisis cuantitativo de dos ejemplos construidos. Dicho análisis se lleva a cabo por medio del método de los elementos finitos y nos permite comprender el comportamiento de este material, así como comparar los resultados con los obtenidos de la bibliografía. Para entender de mejor modo el funcionamiento de este material se ha optado por analizar dos obras de muy diversa índole, por un lado se analiza una obra nueva para comprender la efectividad dentro de este ámbito y por otra parte se analiza una intervención dentro del segmento de las rehabilitaciones para ver su compatibilidad con las estructuras preexistentes

A compact fiber-optic probe-based singlet oxygen luminescence detection system

This paper presents a novel compact fiberoptic basedsinglet oxygen near-infrared luminescence probe coupledto an InGaAs/InP single photon avalanche diode (SPAD)detector. Patterned time gating of the single-photon de-tector is used to limit unwanted dark counts and eliminatethe strong photosensitizer luminescence background.Singlet oxygen luminescence detection at 1270 nm is con-firmed through spectral filtering and lifetime fitting forRose Bengal in water, and Photofrin in methanol as mod-el photosensitizers. The overall performance, measuredby the signal-to-noise ratio, improves by a factor of 50over a previous system that used a fiberoptic-coupledsuperconducting nanowire single-photon detector. Theeffect of adding light scattering to the photosensitizer isalso examined as a first step towards applications in tissuein vivo

Prospective clinical and DaT-SPECT imaging in premotor LRRK2 G2019S-associated Parkinson disease

Objective: To assess the value of baseline clinical and imaging biomarkers in a cohort of asymptomatic LRRK2 G2019S carriers for predicting conversion to Parkinson disease (PD) at 4 years. Methods: Thirty-two asymptomatic carriers of LRRK2 G2019S mutation underwent baseline and 4-year evaluation including clinical examination (Unified Parkinson?s Disease Rating Scale, part III, olfaction University of Pennsylvania Smell Identification Test [UPSIT]) and dopamine transporter (DaT) SPECT (123I-ioflupane). Visual and semiquantitative analysis of images was performed. The specific striatal binding ratio was calculated (striatal region of interest [ROI] 2 occipital ROI/ occipital ROI). Results: Three carriers, asymptomatic at baseline, had converted to PD at 4-year evaluation. Twenty-three participants were fully evaluated. PD converters had lower striatal DaT binding at baseline than nonconverters (p 50.002). A baseline scan with a ratio of bilateral striatal uptake below 1 predicted conversion to PD within the 4-year period with high sensitivity and specificity (area under the curve 1; p 5 0.006). The slope of DaT binding decline between the 2 scans was similar in PD converters and nonconverters. Age-adjusted UPSIT score at baseline and at 4 years was similar in both groups. Conclusions: Semiquantitative DaT-SPECT could be used to predict early conversion to PD in asymptomatic carriers of the LRRK2 G2019S mutation. Rate of conversion to PD at 4 years in this cohort aged ;64 years was 12%. The slope of DaT binding decline on DaT-SPECT imaging seems to be similar across different stages of the premotor perio

Photoantimicrobial Biohybrids by Supramolecular Immobilization of Cationic Phthalocyanines onto Cellulose Nanocrystals

This is the peer-reviewed version of the following article: Anaya‐Plaza, E., van de Winckel, E., Mikkilä, J., Malho, J. M., Ikkala, O., Gulías, O., ... & Kostiainen, M. A. (2017). Photoantimicrobial biohybrids by supramolecular immobilization of cationic phthalocyanines onto cellulose nanocrystals. Chemistry–A European Journal, 23(18), 4320-4326., which has been published in final form at https://doi.org/10.1002/chem.201605285. This article may be used for non-commercial purposes in accordance with Wiley-VCH Terms and Conditions for Self-ArchivingThe development of photoactive and biocompatible nanostructures is a highly desirable goal to address the current threat of antibiotic resistance. Here, we describe a novel supramolecular biohybrid nanostructure based on the non-covalent immobilization of cationic zinc phthalocyanine (ZnPc) derivatives onto unmodified cellulose nanocrystals (CNC), following an easy and straightforward protocol, in which binding is driven by electrostatic interactions. These non-covalent biohybrids show strong photodynamic activity against S. aureus and E. coli, representative examples of Gram-positive and Gram-negative bacteria, respectively, and C. albicans, a representative opportunistic fungal pathogen, outperforming the free ZnPc counterparts and related nanosystems in which the photosensitizer is covalently linked to the CNC surfaceA.d.l.E. acknowledges a Ramón y Cajal contract from the Spanish Ministry of Economy (MINECO). The work at Madrid was supported by the EU [SO2S (FP7‐PEOPLE‐2012‐ITN, 316975); and CosmoPHOS‐nano (FP7‐NMP‐2012‐6, 310337‐2)], the Spanish MINECO [CTQ‐2014‐52869‐P (T.T.) and CTQ‐2014‐53673‐P (A.d.l.E.)] and Comunidad de Madrid [FOTOCARBON (S2013/MIT‐2841)]. J.M., V.L., and M.A.K. acknowledge support through the Emil Aaltonen Foundation and the Academy of Finland (grants 267497, 273645 and 263504). This work was supported by the Academy of Finland through its Centers of Excellence Programme (2014–2019) and made use of the Aalto University Nanomicroscopy Centre (Aalto NMC). The work in Barcelona was supported by the Spanish MINECO (grant CTQ2013‐48767‐C3‐1‐R). R.B.‐O. thanks the European Social Funds and the SUR del DEC de la Generalitat de Catalunya for his predoctoral fellowship (2016 FI B1 00021)

18F-FDG PET/CT in the follow-up of large-vessel vasculitis: A study of 37 consecutive patients

Objective 18F-FDG PET/CT has proved to be of potential value for early diagnosis of large-vessel vasculitis (LVV), which frequently involves the aorta. However, its role in the follow-up of these patients has not been well established. Our aim was to evaluate the contribution of 18F-FDG PET/CT in this clinical situation. Methods This study included 37 consecutive patients (28 women, 66.5 ± 9.9 years) with an initial 18F-FDG PET/CT positive for LVV and a mean ± standard deviation follow-up PET/CT of 7.5 ± 2.9 months after the initial scan. A semiquantitative analysis of aortic wall uptake was performed calculating the target-to-background ratio (TBR: aortic wall uptake divided by blood pool uptake). The initial and follow-up TBR as well as the clinical and laboratory outcome were compared. Results Overall, the mean TBR decreased from 1.7 ± 0.5 at the initial scan to 1.5 ± 0.3 at the time of follow-up (p = 0.0001). In the 21 patients who experienced clinical improvement following therapy the TBR also decreased from 1.8 ± 0.6 to 1.5 ± 0.3 (p = 0.0002). However, in the other 16 patients, in whom the treating physician considered that there was no clinical improvement following therapy, no statistically significant differences in TBR were found when data from the first and the follow-up PET/CT scans were compared (1.6 ± 0.3 versus 1.5 ± 0.3, p = 0.1416). Patients who experienced clinical improvement following therapy showed a nonstatistically significant higher TBR at the time of disease diagnosis (1.8 ± 0.6 versus 1.6 ± 0.3; p = 0.12). Conclusions The results obtained in the present study highlight the impact of 18F-FDG PET/CT on the management of patients with LVV.Professor Gonzalez-Gay´s research was supported by “Fondo de Investigación Sanitaria” (grant PI12/00060 and PI15/00525) from “Instituto de Salud Carlos III” (ISCIII, Health Ministry, Spain). His work is also partially supported by RETICS Programs RD12/0009 (RIER) from ISCIII (Spain) (RD16/0012/0009)

Singlet oxygen production and in vitro phototoxicity studies on fenofibrate, mycophenolate mofetil, trifusal, and their active metabolites

"This is the peer reviewed version of the following article: Molins-Molina, Oscar, Roger Bresolí-Obach, Guillermo Garcia-Lainez, Inmaculada Andreu, Santi Nonell, Miguel A. Miranda, and M. Consuelo Jiménez. 2017. Singlet Oxygen Production and in Vitro Phototoxicity Studies on Fenofibrate, Mycophenolate Mofetil, Trifusal, and Their Active Metabolites. Journal of Physical Organic Chemistry 30 (9). Wiley: e3722. doi:10.1002/poc.3722, which has been published in final form at https://doi.org/10.1002/poc.3722. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."[EN] Singlet oxygen photosensitization (studied by time-resolved near-infrared emission spectroscopy) and in vitro phototoxicity (by means of the 3T3 neutral red uptake assay) have been investigated for the prodrugs fenofibrate (FFB), mycophenolate mofetil (MMP), and trifusal (TFS) as well as for their active metabolites fenofibric acid (FFA), mycophenolic acid (MPA), and 2-hydroxy-4-(trifluoromethyl) benzoic acid (HTB). The results show that FFB and its active metabolite FFA generate O-1(2) with a quantum yield in the range 0.30 to 0.40 and show a photo-irritation factor (PIF) higher than 40. By contrast, MMP/MPA and TFS/HTB are not photoactive in the used assays. These results correlate well with the previously reported in vivo phototoxicity in treated patients.This work has been supported by grants CTQ-2013-47872C2-1-P, CTQ2016-78875-P, CTQ2013-48767-C3-1-R, CTQ2016-78454-C2-1-R, CTQ2015-71896-REDT, FIS PI16/01877, and BES-2014-069404 ( predoctoral fellowship to O. M.- M.) from MINECO. R. B.- O. thanks the European Social Funds and the SUR del DEC de la Generalitat de Catalunya for a predoctoral fellowship (2017 FI_B2 00140).Molins-Molina, O.; Bresolí-Obach, R.; García-Laínez, G.; Andreu Ros, MI.; Nonell, S.; Miranda Alonso, MÁ.; Jiménez Molero, MC. (2017). Singlet oxygen production and in vitro phototoxicity studies on fenofibrate, mycophenolate mofetil, trifusal, and their active metabolites. Journal of Physical Organic Chemistry. 30(9):1-7. https://doi.org/10.1002/poc.3722S17309Nassar, A. F. (Ed.). (2010). Biotransformation and Metabolite Elucidation of Xenobiotics. doi:10.1002/9780470890387Iyanagi, T. (2007). Molecular Mechanism of Phase I and Phase II Drug‐Metabolizing Enzymes: Implications for Detoxification. International Review of Cytology, 35-112. doi:10.1016/s0074-7696(06)60002-8Testa, B., Pedretti, A., & Vistoli, G. (2012). Reactions and enzymes in the metabolism of drugs and other xenobiotics. Drug Discovery Today, 17(11-12), 549-560. doi:10.1016/j.drudis.2012.01.017Foote, C. S. (1991). DEFINITION OF TYPE I and TYPE II PHOTOSENSITIZED OXIDATION. Photochemistry and Photobiology, 54(5), 659-659. doi:10.1111/j.1751-1097.1991.tb02071.xPalumbo, F., Garcia-Lainez, G., Limones-Herrero, D., Coloma, M. D., Escobar, J., Jiménez, M. C., … Andreu, I. (2016). Enhanced photo(geno)toxicity of demethylated chlorpromazine metabolites. Toxicology and Applied Pharmacology, 313, 131-137. doi:10.1016/j.taap.2016.10.024Ljunggren, B., & Möller, H. (1977). Phenothiazine Phototoxicity: an Experimental Study on Chlorpromazine and its Metabolites. Journal of Investigative Dermatology, 68(5), 313-317. doi:10.1111/1523-1747.ep12494582Filippatos, T., & Milionis, H. J. (2008). Treatment of hyperlipidaemia with fenofibrate and related fibrates. Expert Opinion on Investigational Drugs, 17(10), 1599-1614. doi:10.1517/13543784.17.10.1599Mele, T. S., & Halloran, P. F. (2000). The use of mycophenolate mofetil in transplant recipients. Immunopharmacology, 47(2-3), 215-245. doi:10.1016/s0162-3109(00)00190-9Plaza, L., López-Bescós, L., Martín-Jadraque, L. M., Alegrla, E., Cruz-Fernández, J. M., Velasco, J., … Zurita, A. F. (1993). Protective Effect of Triflusal against Acute Myocardial Infarction in Patients with Unstable Angina: Results of a Spanish Multicenter Trial. Cardiology, 82(6), 388-398. doi:10.1159/000175892De La Cruz, J. P., Mata, J. M., & De La Cuesta, F. S. (1992). Triflusal vs aspirin on the inhibition of human platelet and vascular cyclooxygenase. General Pharmacology: The Vascular System, 23(2), 297-300. doi:10.1016/0306-3623(92)90027-hVan Gelder, T., & Hesselink, D. A. (2015). Mycophenolate revisited. Transplant International, 28(5), 508-515. doi:10.1111/tri.12554Kuypers, D. R. J., Meur, Y. L., Cantarovich, M., Tredger, M. J., Tett, S. E., Cattaneo, D., … Gelder, T. van. (2010). Consensus Report on Therapeutic Drug Monitoring of Mycophenolic Acid in Solid Organ Transplantation. Clinical Journal of the American Society of Nephrology, 5(2), 341-358. doi:10.2215/cjn.07111009Ramis, J., Mis, R., Forn, J., Torrent, J., Gorina, E., & Jané, F. (1991). Pharmacokinetics of triflusal and its main metabolite HTB in healthy subjects following a single oral dose. European Journal of Drug Metabolism and Pharmacokinetics, 16(4), 269-273. doi:10.1007/bf03189971Darmanyan, A. P., & Foote, C. S. (1993). Solvent effects on singlet oxygen yield from n,.pi.* and .pi.,.pi.* triplet carbonyl compounds. The Journal of Physical Chemistry, 97(19), 5032-5035. doi:10.1021/j100121a029Wilkinson, F., Helman, W. P., & Ross, A. B. (1995). Rate Constants for the Decay and Reactions of the Lowest Electronically Excited Singlet State of Molecular Oxygen in Solution. An Expanded and Revised Compilation. Journal of Physical and Chemical Reference Data, 24(2), 663-677. doi:10.1063/1.555965Thomas, M. J., & Foote, C. S. (1978). CHEMISTRY OF SINGLET OXYGEN—XXVI. PHOTOOXYGENATION OF PHENOLSy. Photochemistry and Photobiology, 27(6), 683-693. doi:10.1111/j.1751-1097.1978.tb07665.xAfshari, E., & Schmidt, R. (1991). Isotope-dependent quenching of singlet molecular oxygen (1Δg) by ground-state oxygen in several perhalogenated solvents. Chemical Physics Letters, 184(1-3), 128-132. doi:10.1016/0009-2614(91)87176-cBoscá, F., & Miranda, M. A. (1999). A Laser Flash Photolysis Study on Fenofibric Acid. Photochemistry and Photobiology, 70(6), 853-857. doi:10.1111/j.1751-1097.1999.tb08293.xOECD 2004 In vitro thSerrano, G., Fortea, J. M., Latasa, J. M., Millan, F., Janes, C., Bosca, F., & Miranda, M. A. (1992). Photosensitivity induced by fibric acid derivatives and its relation to photocontact dermatitis to ketoprofen. Journal of the American Academy of Dermatology, 27(2), 204-208. doi:10.1016/0190-9622(92)70171-bCosa, G., Purohit, S., Scaiano, J. C., Boscá, F., & Miranda, M. A. (2002). A Laser Flash Photolysis Study of Fenofibric Acid in Aqueous Buffered Media: Unexpected Triplet State Inversion in a Derivative of 4-Alkoxybenzophenone¶. Photochemistry and Photobiology, 75(3), 193. doi:10.1562/0031-8655(2002)0752.0.co;2Vayá, I., Andreu, I., Monje, V. T., Jiménez, M. C., & Miranda, M. A. (2015). Mechanistic Studies on the Photoallergy Mediated by Fenofibric Acid: Photoreactivity with Serum Albumins. 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NanoDCFH-DA: a silica based nanostructured fluorogenic probe for the detection of reactive oxygene species

A biocompatible fluorescent nanoprobe for the detection of reactive oxygen species in biological systems has been designed, synthesized and characterized, circumventing some of the limitations of the molecular probe diacetyl 2',7'-dihidrochlorodihydrofluorescein (DCFH-DA). It has been synthesized the nanoparticulate forme of DCFH-DA by convalently attaching the widely used fluorescent probe DCFH-DA to a mesoporous silica nanoparticle though a linker, The reactivity of nanoDCFH-DA has been tested toward several reactive oxygen species. In addition, it has been proven to slow down DCFH-DA reaction with molecular oxygen and it hampers from interactions with proteins. As a final piece of evidence, in vitro studies showed that the nanoprobe is internalized HeLa cancer cells, thus being capable of detecting intracellularly generated reactive oxygen species. To sum up, it can be stated that nanoDCFH-DA overcomes two major problems of free DCFH-DA, namely oxidation of the probe by air and interaction with proteins in biological systems. This 'nano' approach has thus proven useful to extend the utility of an existing and valuable fluorescent probe to complex biological systems