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Photophysical properties and photodynamic activity of a novel menthol–zinc phthalocyanine conjugate incorporated in micelles phthalocyanine conjugate incorporated in micelles
Abstracts / Photodiagnosis and Photodynamic Therapy 12 (2015) 325–375
for photodynamic therapy in cancer and a potential alternative treatment to conventional chemotherapeutics, such as cisplatin. http://dx.doi.org/10.1016/j.pdpdt.2015.07.057 Synthesis of a new bacteriochlorin derivative with long-wavelength absorption: A potential dye for use as a photosensitizer Francisco F. de Assis, Timothy J. Brocksom, Kleber T. de Oliveira Department of Chemistry, Federal University of São Carlos, Brazil Bacteriochlorins are very attractive candidates for use in photodynamic therapy (PDT) due to their important photophysical properties and absorption bands at the infrared region. These compounds can be obtained from natural sources, such as cyanobacteria and are denominated bacteriochlorophylls. However, the syntheses of these structures are very laborious and represent a challenge from the synthetic point of view. In our research, we have prepared a new bacteriochlorin compound, which presents a strong absorption band around 800 nm. This structure was obtained by the Sonogashira cross-coupling between a tetrabromo bacteriochlorin, prepared by Lindsey’s methodology and phenylacetylene. Currently, we are evaluating the photophysical properties of this new compound as a photosensitizer for use in PDT treatment. http://dx.doi.org/10.1016/j.pdpdt.2015.07.058 Nanobody-targeted photodynamic therapy for oncology Raimond Heukers, Paul M.P. van Bergen en Henegouwen, Sabrina Oliveira Molecular Oncology, Division of Cell Biology, Department of Biology, Faculty of Science, Utrecht University, The Netherlands Monoclonal antibodies have been employed to target photosensitizers (PS) and improve tumor selectivity in photodynamic therapy (PDT). However, antibody-PS conjugates have a long blood half-life and a relatively poor tumor penetration, which result in long photosensitivity in patients and limited therapeutic efficacy. In an attempt to target PS specifically and homogenously to tumors and to accelerate PS clearance, we have developed new conjugates consisting of nanobodies targeting the epidermal growth factor receptor (EGFR) and a traceable PS (IRDye700DX). Nanobodies are the variable domain of heavy-chain antibodies existent in camelids and have a great potential in cancer imaging and therapy. The selected PS is a silicon-phthalocyanine derivative that is more hydrophilic than common PS and is suitable for nearinfrared imaging. The fluorescent nanobody-PS conjugates allow the distinction of cell lines with different expression levels of EGFR. These conjugates specifically induce cell death of EGFR overexpressing cells, while PS alone or the nanobody-PS conjugates in absence of light induce no toxicity. Delivery of PS using internalizing biparatopic nanobody-PS conjugates results in even more pronounced toxicities. Initial in vivo studies point towards a potent therapy, enabling the combination with molecular imaging, which can have a significant impact in the field of targeted PDT. http://dx.doi.org/10.1016/j.pdpdt.2015.07.059
339
Ru(II) complexes as potent photosensitizers in Photodynamic Therapy Gilles Gasser University of Zurich, Switzerland Over the past few years, there has been a growing interest in the use of Ru(II) complexes as photosensitizers (PSs) in the field of Photodynamic Therapy (PDT). Indeed, such metal complexes have the potential to overcome certain drawbacks (e.g. low solubility, tedious synthesis, photobleaching, etc.) that approved PSs inherently have. During this talk, our recent findings on this topic will be discussed. We will notably present our promising biological results obtained not only on cancer cells but also on bacteria. Finally, as an outlook, we will also discuss our preliminary results on a method to kill cancer cells with light but which do not require the presence of oxygen. http://dx.doi.org/10.1016/j.pdpdt.2015.07.060 Photophysical properties and photodynamic activity of a novel menthol–zinc phthalocyanine conjugate incorporated in micelles phthalocyanine conjugate incorporated in micelles Paulina Romero 1,2,3,4 , Nicholas Gobo 1,2,3,4 , Kleber Oliveira 1,2,3,4 , Yassuko Iamamoto 1,2,3,4 , Osvaldo Serra 1,2,3,4 , Sonia Louro 1,2,3,4 1 Departamento de Materiales, Escuela Politécnica Nacional, Quito, Ecuador 2 Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro, Rio de Janeiro, Brazil 3 Departamento de Química, Universidade Federal de São Carlos, São Carlos, SP, Brazil 4 Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Brazil
The new phthalocyanine: tetra-methyl substituted zinc phthalocyanine (ZnMintPc, main regioisomer {2,9,16,23-tetrakis {[(1S,2R,5S)-5-methyl-2-(1-methylethyl)cyclohexyl]oxy}-phthalocyaninato}zinc(II)) presented remarkable structural and photophysical features with potential application in photodynamic therapy (PDT) involving hydrophobic membrane regions. This photosensitizer was incorporated in micelles of 12 different surfactants, namely ionic detergents SDS, CTAB, and HPS, the non-ionic detergents Tween® 20, Tween® 80, C12E9, Brij® 30, Brij® 35, Brij® 97, and Brij® 98, and the triblock copolymers Pluronic F-68 and Pluronic F-127. Solubilization or aggregation in the lipophilic compartment of the micelles was assessed by UV–vis absorption and photoluminescence spectroscopies. Singlet oxygen was produced by irradiation of the micelles with light from red LEDs, peaked at 635 nm, and the quantum yields were obtained using 1,3-diphenylisobenzofuran (DPBF) as probe. Two micellar systems, more specifically Brij® 30 and Pluronic® F-127, displayed excellent ability to generate singlet oxygen. Photobleaching rates of the ZnMintPc incorporated into the micelles were also obtained. The results demonstrated the lipophilic ZnMintPc is suitable for PDT applications and suggest the use of Pluronic® F-127 in the formulation of adequate drug delivery systems for this photosensitizer. http://dx.doi.org/10.1016/j.pdpdt.2015.07.061
for photodynamic therapy in cancer and a potential alternative treatment to conventional chemotherapeutics, such as cisplatin. http://dx.doi.org/10.1016/j.pdpdt.2015.07.057 Synthesis of a new bacteriochlorin derivative with long-wavelength absorption: A potential dye for use as a photosensitizer Francisco F. de Assis, Timothy J. Brocksom, Kleber T. de Oliveira Department of Chemistry, Federal University of São Carlos, Brazil Bacteriochlorins are very attractive candidates for use in photodynamic therapy (PDT) due to their important photophysical properties and absorption bands at the infrared region. These compounds can be obtained from natural sources, such as cyanobacteria and are denominated bacteriochlorophylls. However, the syntheses of these structures are very laborious and represent a challenge from the synthetic point of view. In our research, we have prepared a new bacteriochlorin compound, which presents a strong absorption band around 800 nm. This structure was obtained by the Sonogashira cross-coupling between a tetrabromo bacteriochlorin, prepared by Lindsey’s methodology and phenylacetylene. Currently, we are evaluating the photophysical properties of this new compound as a photosensitizer for use in PDT treatment. http://dx.doi.org/10.1016/j.pdpdt.2015.07.058 Nanobody-targeted photodynamic therapy for oncology Raimond Heukers, Paul M.P. van Bergen en Henegouwen, Sabrina Oliveira Molecular Oncology, Division of Cell Biology, Department of Biology, Faculty of Science, Utrecht University, The Netherlands Monoclonal antibodies have been employed to target photosensitizers (PS) and improve tumor selectivity in photodynamic therapy (PDT). However, antibody-PS conjugates have a long blood half-life and a relatively poor tumor penetration, which result in long photosensitivity in patients and limited therapeutic efficacy. In an attempt to target PS specifically and homogenously to tumors and to accelerate PS clearance, we have developed new conjugates consisting of nanobodies targeting the epidermal growth factor receptor (EGFR) and a traceable PS (IRDye700DX). Nanobodies are the variable domain of heavy-chain antibodies existent in camelids and have a great potential in cancer imaging and therapy. The selected PS is a silicon-phthalocyanine derivative that is more hydrophilic than common PS and is suitable for nearinfrared imaging. The fluorescent nanobody-PS conjugates allow the distinction of cell lines with different expression levels of EGFR. These conjugates specifically induce cell death of EGFR overexpressing cells, while PS alone or the nanobody-PS conjugates in absence of light induce no toxicity. Delivery of PS using internalizing biparatopic nanobody-PS conjugates results in even more pronounced toxicities. Initial in vivo studies point towards a potent therapy, enabling the combination with molecular imaging, which can have a significant impact in the field of targeted PDT. http://dx.doi.org/10.1016/j.pdpdt.2015.07.059
339
Ru(II) complexes as potent photosensitizers in Photodynamic Therapy Gilles Gasser University of Zurich, Switzerland Over the past few years, there has been a growing interest in the use of Ru(II) complexes as photosensitizers (PSs) in the field of Photodynamic Therapy (PDT). Indeed, such metal complexes have the potential to overcome certain drawbacks (e.g. low solubility, tedious synthesis, photobleaching, etc.) that approved PSs inherently have. During this talk, our recent findings on this topic will be discussed. We will notably present our promising biological results obtained not only on cancer cells but also on bacteria. Finally, as an outlook, we will also discuss our preliminary results on a method to kill cancer cells with light but which do not require the presence of oxygen. http://dx.doi.org/10.1016/j.pdpdt.2015.07.060 Photophysical properties and photodynamic activity of a novel menthol–zinc phthalocyanine conjugate incorporated in micelles phthalocyanine conjugate incorporated in micelles Paulina Romero 1,2,3,4 , Nicholas Gobo 1,2,3,4 , Kleber Oliveira 1,2,3,4 , Yassuko Iamamoto 1,2,3,4 , Osvaldo Serra 1,2,3,4 , Sonia Louro 1,2,3,4 1 Departamento de Materiales, Escuela Politécnica Nacional, Quito, Ecuador 2 Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro, Rio de Janeiro, Brazil 3 Departamento de Química, Universidade Federal de São Carlos, São Carlos, SP, Brazil 4 Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Brazil
The new phthalocyanine: tetra-methyl substituted zinc phthalocyanine (ZnMintPc, main regioisomer {2,9,16,23-tetrakis {[(1S,2R,5S)-5-methyl-2-(1-methylethyl)cyclohexyl]oxy}-phthalocyaninato}zinc(II)) presented remarkable structural and photophysical features with potential application in photodynamic therapy (PDT) involving hydrophobic membrane regions. This photosensitizer was incorporated in micelles of 12 different surfactants, namely ionic detergents SDS, CTAB, and HPS, the non-ionic detergents Tween® 20, Tween® 80, C12E9, Brij® 30, Brij® 35, Brij® 97, and Brij® 98, and the triblock copolymers Pluronic F-68 and Pluronic F-127. Solubilization or aggregation in the lipophilic compartment of the micelles was assessed by UV–vis absorption and photoluminescence spectroscopies. Singlet oxygen was produced by irradiation of the micelles with light from red LEDs, peaked at 635 nm, and the quantum yields were obtained using 1,3-diphenylisobenzofuran (DPBF) as probe. Two micellar systems, more specifically Brij® 30 and Pluronic® F-127, displayed excellent ability to generate singlet oxygen. Photobleaching rates of the ZnMintPc incorporated into the micelles were also obtained. The results demonstrated the lipophilic ZnMintPc is suitable for PDT applications and suggest the use of Pluronic® F-127 in the formulation of adequate drug delivery systems for this photosensitizer. http://dx.doi.org/10.1016/j.pdpdt.2015.07.061