Photophysical properties of porphyrins, phthalocyanines, and benzochlorins

Owens, John; Smith, Randelon; Robinson, Ryan; Robins, Marsha

doi:10.1016/s0020-1693(98)00137-6

Cited by 96 publications

(48 citation statements)

References 21 publications

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“…Nesses compósitos, o corante fotossensibilizador ao ser eletronicamente excitado, tende a injetar elétrons na banda de condução do TiO 2 , o que proporciona o ganho de eficiência observado 28,29 . Também, é possível que haja, nesse caso, a participação do oxigênio singlete como espécie reativa, já que a ftalocianina de zinco, além de intermediar reações Tipo I (transferência de elétron), é também eficiente na sensitização de reações Tipo II (transferência de energia) 30,31 . Uma redução na DQO de cerca de 60% foi obtida empregandose TiO 2 como catalisador, após uma dose acumulada de radiação UV-A de cerca de 610 kJ/m 2 , o que corresponde, nas condições da cidade de Uberlândia, em um dia ensolarado, a menos de 2 h de reação, ou 4 h para um dia de nebulosidade moderada a alta.…”

Section: Fotocatálise Heterogênea: Degradação De Um Modelo De Efluentunclassified

Construção e estudos de perfomance de um reator fotoquímico tipo CPC ("Compound Parabolic Concentrator")

Duarte¹,

Xavier²,

Souza³

et al. 2005

Quím. Nova

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Recebido em 13/1/04; aceito em 27/1/05; publicado na web em 30/6/05 CONSTRUCTION AND PERFORMANCE STUDIES OF A CPC TYPE PHOTOCHEMICAL REACTOR. A CPC (Compound Parabolic Concentrator) reactor was projected and constructed aiming to promote the degradation of the organic matter present in considerable volumes of aqueous effluents, under the action of solar radiation. The essays were done using a model effluent which consists of a mixture of fragments of a sodium salt of lignosulphonic acid possessing a mean molecular weigth of 52,000 Daltons, and a real effluent, from a chip board industry. The volume of effluent in each test was about 50 L. The tests involved heterogeneous (TiO 2 P25 Degussa and formulations made from the association of TiO 2 with a photosensitiser), and homogeneous (thermal and photochemical Fenton reactions) catalysis of the effluents. The results demonstrate the viability of application of this kind of reactor even when the load of organic pollutants is high.

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Section: Fotocatálise Heterogênea: Degradação De Um Modelo De Efluentunclassified

Construção e estudos de perfomance de um reator fotoquímico tipo CPC ("Compound Parabolic Concentrator")

Duarte¹,

Xavier²,

Souza³

et al. 2005

Quím. Nova

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“…7 Moreover, ZnPc has a large absorption cross-section of light at the tissue-penetrating spectral range of 650-900 nm. 7,8 The biggest hurdle for most photosensitizers, including ZnPc, for PDT is the low physiological acceptance level owing to their high hydrophobic characteristics responsible for the poor solubility in a bodily fluid. To overcome this problem, ZnPc derivatives, such as tetrasulfonated ZnPc (ZnPcS 4 ), 9 [1,2,3,4-tetrakis(a/b-Dgalactopyranos-6-yl)-phthalocyaninato]zinc, 10 tetra-and octatriethyleneoxysulfonyl substituted ZnPc, 11 have been designed to increase the water solubility.…”

Section: Introductionmentioning

confidence: 99%

Significant increase in the water dispersibility of zinc phthalocyanine nanowires and applications in cancer phototherapy

et al. 2012

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The phototherapy is one of the widely accepted noninvasive clinical methodologies to eradicate cancer cells owing to its minimal side effects and high selectivity to the light of specific wavelength. As represented by photodynamic (PD) and photothermal (PT) therapy, the phototherapy requires light and photosensitizer to generate reactive oxygen species and heat, respectively. Zinc phthalocyanine (ZnPc) is one of the promising photosensitizers as it has a strong absorption cross-section in the spectral range of 650-900 nm that guarantees maximum tissue penetration. One critical issue in using Pc molecule, including ZnPc as a biocompatible sensitizer is the poor water solubility. To increase water solubility, various chemical modifications inducing hydrophilicity have been widely attempted to introduce various functional groups in the ZnPc backbone. We report that ZnPc nanowires (NWs) directly grown from ZnPc powder by vaporization-condensation-recrystallization process show surprisingly increased water dispersibility without any functionalization. The ZnPc NW solution exhibits highly efficient dual PD and PT effects upon the irradiation of near infrared (808 nm) laser. The dual phototherapeutic effect of ZnPc NW is proven to enhance cytotoxic efficiency according to both in vitro and in vivo experimental results. NPG Asia Materials (2012) 4, e12; doi:10.1038/am.2012.22; published online 13 April 2012Keywords: nanowire; photosensitizer; phototherapy; Zinc phthalocyanine INTRODUCTION Phototherapy, represented by photodynamic therapy (PDT) and photothermal therapy (PTT), is an advanced modality for the treatment of malignant tumors as it is widely used for clinical cancer treatments. PDT selectively destroys neoplastic lesions using cytotoxic reactive oxygen species (ROS) generated by light activation of the photosensitizer. 1,2 One of the crucial factors determining the PDT efficacy is the photochemical and photophysical properties of the photosensitizer. 3,4 Currently, four main classes of photosensitizer, such as porphyrin derivatives, chlorins, porphycenes, and phthalocyanines (Pcs), have been approved by the U.S. Food and Drug Administration (FDA) for clinical applications against cancer. 5,6 Among these, metallo-phthalocyanine has attracted considerable interest, having a photodynamic (PD) property that can be readily tuned by the type of central metal ion and the functional groups introduced as a Pc ring substituent. Zinc phthalocyanine (ZnPc) is known to exhibit a high PD effect as it possesses a diamagnetic Zn(II) central metal ion whose d shell is fully occupied, by which the yield of triplet excited state with long lifetime essential for the generation of ROS becomes high. 7 Moreover, ZnPc has

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“…ZnPc is a promising photosensitizer for PDT (20)(21)(22) because of its high optical absorption coefficient in the 600-to 800-nm phototherapeutic window; this coefficient is higher than that of currently used porphyrin (16)(17)(18)(19). However, ZnPc is hydrophobic and prone to self-aggregation in aqueous solutions, which drastically reduces the photosensitizing efficiency (23).…”

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confidence: 99%

Fabrication of ZnPc/protein nanohorns for double photodynamic and hyperthermic cancer phototherapy

Zhang

Murakami

Ajima

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

252

186

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Multifunctionalization of carbon nanotubules is easily achieved by attaching functional molecules that provide specific advantages for microscopic applications. We fabricated a double photodynamic therapy (PDT) and photohyperthermia (PHT) cancer phototherapy system that uses a single laser. Zinc phthalocyanine (ZnPc) was loaded onto single-wall carbon nanohorns with holes opened (SWNHox), and the protein bovine serum albumin (BSA) was attached to the carboxyl groups of SWNHox. In this system, ZnPc was the PDT agent, SWNHox was the PHT agent, and BSA enhanced biocompatibility. The double phototherapy effect was confirmed in vitro and in vivo. When ZnPc-SWNHox-BSA was injected into tumors that were subcutaneously transplanted into mice, the tumors almost disappeared upon 670-nm laser irradiation. In contrast, the tumors continued to grow when only ZnPc or SWNHox-BSA was injected. We conclude that carbon nanotubules may be a valuable new tool for use in cancer phototherapy.carbon nanotubules ͉ drug carrier ͉ drug delivery system ͉ nanoparticle ͉ photohyperthermia

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Photophysical properties of porphyrins, phthalocyanines, and benzochlorins

Cited by 96 publications

References 21 publications

Construção e estudos de perfomance de um reator fotoquímico tipo CPC ("Compound Parabolic Concentrator")

Construção e estudos de perfomance de um reator fotoquímico tipo CPC ("Compound Parabolic Concentrator")

Significant increase in the water dispersibility of zinc phthalocyanine nanowires and applications in cancer phototherapy

Fabrication of ZnPc/protein nanohorns for double photodynamic and hyperthermic cancer phototherapy

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