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TiO2 spherical structures with potential application for photodynamic therapy
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Abstracts / Photodiagnosis and Photodynamic Therapy 12 (2015) 325–375
24 h receiving the treatment. For toxicity studies, cells remained in contact with the phthalocyanine for 2 and 24 h. For phototoxicity studies, cells remained in contact with the treatment for 2 h, irradiated by laser (660 nm, 8 W/cm2 ) for 20 min and re-incubated for 2, 6, 24 and 48 h. Cells treated with new ruthenium phthalocyanine showed high percentage viability and did not differ much from the untreated control cells, demonstrating the low toxicity of compound. However, a decrease in percentage viability was observed in PDT treated cells showing its potential as a photosensitizer. Further studies of this system are in progress. http://dx.doi.org/10.1016/j.pdpdt.2015.07.144 Studies and application of new eosin analogs for application in photodynamic therapy Kleber Tellini de Andrade, Anderson Orzari Ribeiro Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Brazil Eosin and derivatives have been studied for a long time and their synthesis is very simple and cheap. The first one fotossensibiliador used in photodynamic therapy was eosin, after that, many studies aimed the synthesis of new analogs for these propose. In this work was synthesized with excellent yield ten new analogs of eosin linked to substituents 1 to promote an increased in solubility and in the conjugation of the molecule. The UV–vis spectrum was record in DMSO and showed absorption in the region of 495 nm, within the therapeutic window (400–800 nm). Due to its low cost and easy production, there is the possibility of its use for the treatment not only of superficial tumor, as well pests in crops, cattle and others. http://dx.doi.org/10.1016/j.pdpdt.2015.07.145
TiO2 spherical structures with potential application for photodynamic therapy Carine S.S. Ribeiro, Alessandra Zenatti, Anderson O. Ribeiro Federal University of ABC, Brazil Three-dimensional hollow spherical structures have good performances that attract significant attention nowadays, due to their higher specific surface area, lower density, better cell permeation and greater light-harvesting capacity. Hence, the hollow TiO2 spherical structures has been used in many areas and applications, including photocatalysts, electrochromic devices, gas sensor, dye sensitized solar cells, biomedical implants and field emitters, delivery carriers adsorbents and photodynamic therapy. In this work, hollow TiO2 spherical structures were prepared by microwaveassisted hydrothermal treatment without template. A solution containing 0.2 g of TiO2 amorphous spheres synthetized previously by sol–gel method was mixed with NaF, ethanol and water and transferred to a 100 mL Teflon-lined autoclave, which was sealed and kept at 180 ◦ C for 1 h. After, the material was washed seven times with ethanol and centrifuged. Results of X-ray diffraction (XRD) showed crystal planes of TiO2 anatase. Some tests in photodynamic therapy will be made to evaluate the performance of the material. Other characterization will be realized, such as, superficial area, pore volume and compositional analyzes FTIR and Raman spectroscopy. http://dx.doi.org/10.1016/j.pdpdt.2015.07.147 Combined use of rare earth (RE)-doped nanostructures and photosensitizers (PS): Possible application in photodynamic therapy (PDT)
Synthesis, photochemical and photophysical properties of optically active 2-butanol zinc phthalocyanines
Waléria Ribeiro Lopes, Upendra Kumar Kagola, Francisco G. Rego-Filho, Maria Tereza de Araujo
Aline Alves Ramos, Anderson Orzari Ribeiro
Photonics and Complex Fluids Group (GFFC), Instituto de Física (IF), Universidade Federal de Alagoas (UFAL), Brazil
Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Brazil Phthalocyanines are very promising photosensitizers for photodynamic therapy due to intense absorption in the red region of the optical spectrum (ca. 700 nm) and photophysical properties. The synthesis, photochemical and photophysical characterization was performed for three news zinc phthalocyanines modified with 2-butanol, (R)-(−)-2-butanol, and (S)-(+)-2-butanol. These compounds were characterized by 1 H-NMR. UV–vis and fluorescence spectra were recorded in DMSO to determine the molar absorptivity coefficient, aggregation tendency, fluorescence quantum yield and photodegradation quantum yield. The singlet-oxygen quantum yield was obtained by indirect method, using DBPF as chemical quencher. The news phthalocyanines were synthetized and photophysical properties are similar for three compounds. The quantum yield of singlet oxygen showed better results than standard phthalocyanine demonstrating their potential as photosensitizer for PDT application. However, more studies have to be done to compare the racemic phthalocyanine with their respective isomers R and S. http://dx.doi.org/10.1016/j.pdpdt.2015.07.146
There is a strong limitation on the effectiveness of PDT which is the light penetration depth in biological tissues. In this case, photon absorption and scattering occur simultaneously as a result of a statistical process. These processes depend directly on the light wavelength and, therefore, influence on the penetration depth. Nonlinear processes (involving more than one photon) have been investigated as a mean to excite selectively PS while decreasing the interaction with the healthy tissue surrounding the cancerous lesions. In this study, the upconversion energy process in rare earth-codoped nanostructures was employed as an excitation mechanism of photosensitizers. The infrared incident radiation achieves greater penetration depths into the tissue, excites the ions in the host nanostructure, and generates light in the visible region of the electromagnetic spectrum. The last emission of these ions is used to excite the PS. Initially, we conducted emission measurements as a function of time for certain concentrations of the solutions (Er/Yb co-doped nanocrystals and Photogem® ). The incident radiation focused on the solution was of a 980 nm diode laser. We investigated the time evolution of the signal generated by those emissions. The proposition may be considered for use in Photodynamic Therapy. http://dx.doi.org/10.1016/j.pdpdt.2015.07.148
Abstracts / Photodiagnosis and Photodynamic Therapy 12 (2015) 325–375
24 h receiving the treatment. For toxicity studies, cells remained in contact with the phthalocyanine for 2 and 24 h. For phototoxicity studies, cells remained in contact with the treatment for 2 h, irradiated by laser (660 nm, 8 W/cm2 ) for 20 min and re-incubated for 2, 6, 24 and 48 h. Cells treated with new ruthenium phthalocyanine showed high percentage viability and did not differ much from the untreated control cells, demonstrating the low toxicity of compound. However, a decrease in percentage viability was observed in PDT treated cells showing its potential as a photosensitizer. Further studies of this system are in progress. http://dx.doi.org/10.1016/j.pdpdt.2015.07.144 Studies and application of new eosin analogs for application in photodynamic therapy Kleber Tellini de Andrade, Anderson Orzari Ribeiro Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Brazil Eosin and derivatives have been studied for a long time and their synthesis is very simple and cheap. The first one fotossensibiliador used in photodynamic therapy was eosin, after that, many studies aimed the synthesis of new analogs for these propose. In this work was synthesized with excellent yield ten new analogs of eosin linked to substituents 1 to promote an increased in solubility and in the conjugation of the molecule. The UV–vis spectrum was record in DMSO and showed absorption in the region of 495 nm, within the therapeutic window (400–800 nm). Due to its low cost and easy production, there is the possibility of its use for the treatment not only of superficial tumor, as well pests in crops, cattle and others. http://dx.doi.org/10.1016/j.pdpdt.2015.07.145
TiO2 spherical structures with potential application for photodynamic therapy Carine S.S. Ribeiro, Alessandra Zenatti, Anderson O. Ribeiro Federal University of ABC, Brazil Three-dimensional hollow spherical structures have good performances that attract significant attention nowadays, due to their higher specific surface area, lower density, better cell permeation and greater light-harvesting capacity. Hence, the hollow TiO2 spherical structures has been used in many areas and applications, including photocatalysts, electrochromic devices, gas sensor, dye sensitized solar cells, biomedical implants and field emitters, delivery carriers adsorbents and photodynamic therapy. In this work, hollow TiO2 spherical structures were prepared by microwaveassisted hydrothermal treatment without template. A solution containing 0.2 g of TiO2 amorphous spheres synthetized previously by sol–gel method was mixed with NaF, ethanol and water and transferred to a 100 mL Teflon-lined autoclave, which was sealed and kept at 180 ◦ C for 1 h. After, the material was washed seven times with ethanol and centrifuged. Results of X-ray diffraction (XRD) showed crystal planes of TiO2 anatase. Some tests in photodynamic therapy will be made to evaluate the performance of the material. Other characterization will be realized, such as, superficial area, pore volume and compositional analyzes FTIR and Raman spectroscopy. http://dx.doi.org/10.1016/j.pdpdt.2015.07.147 Combined use of rare earth (RE)-doped nanostructures and photosensitizers (PS): Possible application in photodynamic therapy (PDT)
Synthesis, photochemical and photophysical properties of optically active 2-butanol zinc phthalocyanines
Waléria Ribeiro Lopes, Upendra Kumar Kagola, Francisco G. Rego-Filho, Maria Tereza de Araujo
Aline Alves Ramos, Anderson Orzari Ribeiro
Photonics and Complex Fluids Group (GFFC), Instituto de Física (IF), Universidade Federal de Alagoas (UFAL), Brazil
Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Brazil Phthalocyanines are very promising photosensitizers for photodynamic therapy due to intense absorption in the red region of the optical spectrum (ca. 700 nm) and photophysical properties. The synthesis, photochemical and photophysical characterization was performed for three news zinc phthalocyanines modified with 2-butanol, (R)-(−)-2-butanol, and (S)-(+)-2-butanol. These compounds were characterized by 1 H-NMR. UV–vis and fluorescence spectra were recorded in DMSO to determine the molar absorptivity coefficient, aggregation tendency, fluorescence quantum yield and photodegradation quantum yield. The singlet-oxygen quantum yield was obtained by indirect method, using DBPF as chemical quencher. The news phthalocyanines were synthetized and photophysical properties are similar for three compounds. The quantum yield of singlet oxygen showed better results than standard phthalocyanine demonstrating their potential as photosensitizer for PDT application. However, more studies have to be done to compare the racemic phthalocyanine with their respective isomers R and S. http://dx.doi.org/10.1016/j.pdpdt.2015.07.146
There is a strong limitation on the effectiveness of PDT which is the light penetration depth in biological tissues. In this case, photon absorption and scattering occur simultaneously as a result of a statistical process. These processes depend directly on the light wavelength and, therefore, influence on the penetration depth. Nonlinear processes (involving more than one photon) have been investigated as a mean to excite selectively PS while decreasing the interaction with the healthy tissue surrounding the cancerous lesions. In this study, the upconversion energy process in rare earth-codoped nanostructures was employed as an excitation mechanism of photosensitizers. The infrared incident radiation achieves greater penetration depths into the tissue, excites the ions in the host nanostructure, and generates light in the visible region of the electromagnetic spectrum. The last emission of these ions is used to excite the PS. Initially, we conducted emission measurements as a function of time for certain concentrations of the solutions (Er/Yb co-doped nanocrystals and Photogem® ). The incident radiation focused on the solution was of a 980 nm diode laser. We investigated the time evolution of the signal generated by those emissions. The proposition may be considered for use in Photodynamic Therapy. http://dx.doi.org/10.1016/j.pdpdt.2015.07.148