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Pires L, Demidov V, Wilson BC, Salvio AG, Moriyama L, Bagnato VS, Vitkin IA, Kurachi C. Dual-Agent Photodynamic Therapy with Optical Clearing Eradicates Pigmented Melanoma in Preclinical Tumor Models. Cancers (Basel) 2020; 12:cancers12071956. [PMID: 32708501 PMCID: PMC7409296 DOI: 10.3390/cancers12071956] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/11/2020] [Accepted: 07/13/2020] [Indexed: 12/17/2022] Open
Abstract
Treatment using light-activated photosensitizers (photodynamic therapy, PDT) has shown limited efficacy in pigmented melanoma, mainly due to the poor penetration of light in this tissue. Here, an optical clearing agent (OCA) was applied topically to a cutaneous melanoma model in mice shortly before PDT to increase the effective treatment depth by reducing the light scattering. This was used together with cellular and vascular-PDT, or a combination of both. The effect on tumor growth was measured by longitudinal ultrasound/photoacoustic imaging in vivo and by immunohistology after sacrifice. In a separate dorsal window chamber tumor model, angiographic optical coherence tomography (OCT) generated 3D tissue microvascular images, enabling direct in vivo assessment of treatment response. The optical clearing had minimal therapeutic effect on the in control, non-pigmented cutaneous melanomas but a statistically significant effect (p < 0.05) in pigmented lesions for both single- and dual-photosensitizer treatment regimes. The latter enabled full-depth eradication of tumor tissue, demonstrated by the absence of S100 and Ki67 immunostaining. These studies are the first to demonstrate complete melanoma response to PDT in an immunocompromised model in vivo, with quantitative assessment of tumor volume and thickness, confirmed by (immuno) histological analyses, and with non-pigmented melanomas used as controls to clarify the critical role of melanin in the PDT response. The results indicate the potential of OCA-enhanced PDT for the treatment of pigmented lesions, including melanoma.
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Affiliation(s)
- Layla Pires
- São Carlos Institute of Physics, University of São Paulo, Sao Carlos-SP 13566-590, Brazil; (L.P.); (L.M.); (V.S.B.); (C.K.)
- Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7, Canada; (V.D.); (I.A.V.)
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2C1, Canada
| | - Valentin Demidov
- Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7, Canada; (V.D.); (I.A.V.)
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2C1, Canada
| | - Brian C. Wilson
- Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7, Canada; (V.D.); (I.A.V.)
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2C1, Canada
- Correspondence: ; Tel.: +1-416-634-8778
| | | | - Lilian Moriyama
- São Carlos Institute of Physics, University of São Paulo, Sao Carlos-SP 13566-590, Brazil; (L.P.); (L.M.); (V.S.B.); (C.K.)
| | - Vanderlei S. Bagnato
- São Carlos Institute of Physics, University of São Paulo, Sao Carlos-SP 13566-590, Brazil; (L.P.); (L.M.); (V.S.B.); (C.K.)
| | - I. Alex Vitkin
- Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7, Canada; (V.D.); (I.A.V.)
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2C1, Canada
| | - Cristina Kurachi
- São Carlos Institute of Physics, University of São Paulo, Sao Carlos-SP 13566-590, Brazil; (L.P.); (L.M.); (V.S.B.); (C.K.)
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Specific Targeting of Melanotic Cells with Peptide Ligated Photosensitizers for Photodynamic Therapy. Sci Rep 2017; 7:15750. [PMID: 29146972 PMCID: PMC5691209 DOI: 10.1038/s41598-017-15142-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 10/18/2017] [Indexed: 02/05/2023] Open
Abstract
A strategy combining covalent conjugation of photosensitizers to a peptide ligand directed to the melanocortin 1 (MC1) receptor with the application of sequential LED light dosage at near-IR wavelengths was developed to achieve specific cytotoxicity to melanocytes and melanoma (MEL) with minimal collateral damage to surrounding cells such as keratinocytes (KER). The specific killing of melanotic cells by targeted photodynamic therapy (PDT) described in this study holds promise as a potentially effective adjuvant therapeutic method to control benign skin hyperpigmentation or superficial melanotic malignancy such as Lentigo Maligna Melanoma (LMM).
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Lee KL, Carpenter BL, Wen AM, Ghiladi RA, Steinmetz NF. High Aspect Ratio Nanotubes Formed by Tobacco Mosaic Virus for Delivery of Photodynamic Agents Targeting Melanoma. ACS Biomater Sci Eng 2016; 2:838-844. [PMID: 28713855 DOI: 10.1021/acsbiomaterials.6b00061] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Melanoma is a highly aggressive cancer that is unresponsive to many traditional therapies. Recently, photodynamic therapy has shown promise in its treatment as an adjuvant therapy. However, conventional photosensitizers are limited by poor solubility and limited accumulation within target tissue. Here, we report the delivery of a porphyrin-based photosensitizer encapsulated within a plant viral nanoparticle. Specifically, we make use of the hollow, high aspect ratio nanotubes formed by the nucleoprotein components of tobacco mosaic virus (TMV) to encapsulate the drug for delivery and targeting of cancer cells. The cationic photosensitizer was successfully and stably loaded into the interior channel of TMV via electrostatic interactions. Cell uptake and efficacy were evaluated using a model of melanoma. The resulting TMV-photosensitizer exhibited improved cell uptake and efficacy when compared to free photosensitizer, making it a promising platform for improved therapy of melanoma.
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Affiliation(s)
- Karin L Lee
- Department of Biomedical Engineering, Schools of Medicine and Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Bradley L Carpenter
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Amy M Wen
- Department of Biomedical Engineering, Schools of Medicine and Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Reza A Ghiladi
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Nicole F Steinmetz
- Department of Biomedical Engineering, Schools of Medicine and Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States.,Department of Radiology, Schools of Medicine and Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States.,Department of Materials Science and Engineering, Schools of Medicine and Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States.,Department of Macromolecular Science and Engineering, Schools of Medicine and Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States.,Case Comprehensive Cancer Center, Schools of Medicine and Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
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Çakır D, Göksel M, Çakır V, Durmuş M, Biyiklioglu Z, Kantekin H. Amphiphilic zinc phthalocyanine photosensitizers: synthesis, photophysicochemical properties and in vitro studies for photodynamic therapy. Dalton Trans 2016; 44:9646-58. [PMID: 25923925 DOI: 10.1039/c5dt00747j] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Peripherally and non-peripherally tetra-substituted zinc(ii) phthalocyanines bearing 2-(2-{2-[3-(dimethylamino)phenoxy]ethoxy}ethoxy)ethoxy and 2-(2-{2-[3-(diethylamino)phenoxy]ethoxy}ethoxy)ethoxy groups (, , and ) were synthesized by cyclotetramerization of the corresponding phthalonitriles (, , and ). Their quaternized ionic derivatives (, , and ) were also synthesized by the reaction of them with methyl iodide. The novel compounds were characterized by using standard spectroscopic techniques such as FT-IR, (1)H NMR, (13)C NMR, UV-vis, mass and elemental analyses. The obtained quaternized phthalocyanines (, , and ) showed amphiphilic behaviour with excellent solubility in both organic and aqueous solutions, which makes them potential photosensitizers for use in photodynamic therapy (PDT) of cancer. The photophysical (fluorescence quantum yields and lifetimes) and photochemical (singlet oxygen and photodegradation quantum yields) properties of these novel phthalocyanines were studied in DMSO for both non-ionic and ionic quaternized derivatives. However, these properties were examined in both DMSO and phosphate buffer solution (PBS) for quaternized ionic phthalocyanines. The effects of the positions of substituents (peripheral or non-peripheral) and the quaternization of the nitrogen atoms on the substituents about their photophysical and photochemical properties were also compared in this study. The bovine serum albumin (BSA) binding behaviours of the studied quaternized ionic zinc(ii) phthalocyanines were also described in PBS solutions. The quaternized phthalocyanines (, , and ) successfully displayed light-dependent photodamage in HeLa and HuH-7 cancer cells in photodynamic therapy treatment. The photosensitivity and the intensity of damage were found directly related to the concentration of the photosensitizers.
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Affiliation(s)
- Dilek Çakır
- Department of Chemistry, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon, Turkey.
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Baldea I, Ion RM, Olteanu DE, Nenu I, Tudor D, Filip AG. Photodynamic therapy of melanoma using new, synthetic porphyrins and phthalocyanines as photosensitisers - a comparative study. ACTA ACUST UNITED AC 2015; 88:175-80. [PMID: 26528068 PMCID: PMC4576792 DOI: 10.15386/cjmed-419] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 03/20/2015] [Accepted: 03/21/2015] [Indexed: 01/06/2023]
Abstract
Melanoma, a cancer that arises from melanocytes, is one of the most unresponsive cancers to known therapies and has a tendency to produce early metastases. Several studies showed encouraging results of the efficacy of photodynamic therapy (PDT) in melanoma, in different experimental settings in vitro and in vivo, as well as several clinical reports.
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Affiliation(s)
- Ioana Baldea
- Department of Physiology, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Rodica-Mariana Ion
- National Institute for Research & Development in Chemistry and Petrochemistry-ICECHIM, Nanomedicine Research Group, Bucharest, Romania ; Materials Engineering Department, Valahia University, Targoviste, Romania
| | - Diana Elena Olteanu
- Department of Physiology, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Iuliana Nenu
- Department of Physiology, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Diana Tudor
- Department of Physiology, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Adriana Gabriela Filip
- Department of Physiology, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
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Photodynamic therapy in treatment of cutaneous and choroidal melanoma. Photodiagnosis Photodyn Ther 2013; 10:503-9. [DOI: 10.1016/j.pdpdt.2013.05.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 05/15/2013] [Accepted: 05/19/2013] [Indexed: 01/10/2023]
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DECREAU RICHARD, RICHARD MARIEJEANNE, JULLIARD MICHEL. Photodynamic therapy against achromic M6 melanocytes: phototoxicity of lipophilic axially substituted aluminum phthalocyanines and hexadecahalogenated zinc phthalocyanines. J PORPHYR PHTHALOCYA 2012. [DOI: 10.1002/jpp.343] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Lipophilic and axially substituted tri-n-hexylsiloxy aluminum phthalocyanine and cholesteryloxy diphenylsiloxy aluminum phthalocyanine were synthesized and assayed in PDT against M6 melanocytes. In the conditions used (λ > 480 nm , 10 mW cm-2, egg-yolk lecithin or cremophor EL formulation) they both exhibited a higher photodynamic effect than chloroaluminum phthalocyanine. They displayed 2% to 3.5% cell viability at 10-5M dose for 20 min irradiation. Hexadecafluoro zinc phthalocyanine was synthesized to increase the lipophilicity of zinc phthalocyanine, hexadecachloro zinc phthalocyanine was also included because it would theoretically enhance the phototoxicity. In all the delivery systems used, their photodynamic effect against M6 melanocytes was lower in comparison with zinc phthalocyanine and axially substituted aluminum phthalocyanines. A 2 h irradiation treatment with 3 × 10-6 M hexadecafluoro zinc phthalocyanine and 10-5 M hexadecachloro zinc phthalocyanine led to 60% and 15% cell viability respectively. In all cases, the cell killing effect was light-and dose-dependent and was higher in cremophor EL micelles than in the egg-yolk lecithin formulation.
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Affiliation(s)
- RICHARD DECREAU
- Laboratoire AM3: Activation, Mécanismes, Modélisation Moléculaire, Faculté des Sciences Saint Jérôme, F-13397 Marseille Cédex 20, France
| | - MARIE-JEANNE RICHARD
- Laboratoire de Biochimie C, Centre Hospitalier Universitaire A. Michallon, BP 217X, F-38043 Grenoble Cédex, France
| | - MICHEL JULLIARD
- Laboratoire AM3: Activation, Mécanismes, Modélisation Moléculaire, Faculté des Sciences Saint Jérôme, F-13397 Marseille Cédex 20, France
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Peternel L, Kristan K, Petruševska M, Rižner TL, Legen I. Suitability of Isolated Rat Jejunum Model for Demonstration of Complete Absorption in Humans for BCS-Based Biowaiver Request. J Pharm Sci 2012; 101:1436-49. [DOI: 10.1002/jps.23027] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Revised: 11/22/2011] [Accepted: 12/02/2011] [Indexed: 12/18/2022]
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Sekkat N, van den Bergh H, Nyokong T, Lange N. Like a bolt from the blue: phthalocyanines in biomedical optics. Molecules 2011; 17:98-144. [PMID: 22198535 PMCID: PMC6269082 DOI: 10.3390/molecules17010098] [Citation(s) in RCA: 183] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 12/05/2011] [Accepted: 12/14/2011] [Indexed: 01/08/2023] Open
Abstract
The purpose of this review is to compile preclinical and clinical results on phthalocyanines (Pcs) as photosensitizers (PS) for Photodynamic Therapy (PDT) and contrast agents for fluorescence imaging. Indeed, Pcs are excellent candidates in these fields due to their strong absorbance in the NIR region and high chemical and photo-stability. In particular, this is mostly relevant for their in vivo activation in deeper tissular regions. However, most Pcs present two major limitations, i.e., a strong tendency to aggregate and a low water-solubility. In order to overcome these issues, both chemical tuning and pharmaceutical formulation combined with tumor targeting strategies were applied. These aspects will be developed in this review for the most extensively studied Pcs during the last 25 years, i.e., aluminium-, zinc- and silicon-based Pcs.
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Affiliation(s)
- Nawal Sekkat
- School of Pharmaceutical Sciences, University of Lausanne/Geneva, Geneva, 30, quai Ernest Ansermet, Geneva CH-1211, Switzerland
| | - Hubert van den Bergh
- Laboratory of Photomedicine, Swiss Federal Institute of Technology (EPFL), Lausanne CH-1015, Switzerland
| | - Tebello Nyokong
- Department of Chemistry, Rhodes University, Grahamstown 6140, South Africa
| | - Norbert Lange
- School of Pharmaceutical Sciences, University of Lausanne/Geneva, Geneva, 30, quai Ernest Ansermet, Geneva CH-1211, Switzerland
- Author to whom correspondence should be addressed; ; Tel.:+41-22-379-3335; Fax: +41-22-379-6567
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Gilaberte Y, Serra-Guillén C, de las Heras ME, Ruiz-Rodríguez R, Fernández-Lorente M, Benvenuto-Andrade C, González-Rodríguez S, Guillén-Barona C. Terapia fotodinámica en dermatología. ACTAS DERMO-SIFILIOGRAFICAS 2006; 97:83-102. [PMID: 16595110 DOI: 10.1016/s0001-7310(06)73359-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Photodynamic therapy (PDT) is a therapeutic modality based on the photooxidation of biological materials induced by a photosensitizer, which selectively locates itself in certain tumorous cells or tissues, so that when illuminated by a light of the right length and at a sufficient dose, these cells are destroyed. In dermatology, PDT with topical 5-aminolevulinic acid or 5-methyl aminolevulinate is very effective in the treatment of actinic keratoses, basal cell carcinomas and Bowen's disease. In addition, very promising results have been obtained in inflammatory pathologies like morphea or sarcoidosis, infections like warts, and cosmetic processes such as photoaging, among others. This article reviews the most significant aspects of PDT in dermatology. First of all, we will review the basic fundamentals of photodynamic treatment. Next, we will outline its clinical applications in dermatology, both in oncological applications and all those dermatological processes in which PDT may play a role in their management. We will also discuss its promising cosmetic application in the treatment of photoaging. We will complete the review with photodiagnosis and the different non-invasive ways to monitor the effectiveness of PDT.
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Córdoba F, Braathen LR, Weissenberger J, Vallan C, Kato M, Nakashima I, Weis J, von Felbert V. 5-aminolaevulinic acid photodynamic therapy in a transgenic mouse model of skin melanoma. Exp Dermatol 2005; 14:429-37. [PMID: 15885078 DOI: 10.1111/j.0906-6705.2005.00303.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Photodynamic therapy (PDT) is widely used to treat preneoplastic skin lesions and non-melanoma skin tumours. Studies analyzing the effects of PDT on malignant melanoma have yielded conflicting results. On the one hand, melanoma cell lines in culture as well as cell lines transplanted into experimental animals were sensitive to PDT. On the other hand, spontaneous melanomas of human patients responded poorly to most PDT regimens tested so far. Here, we analyzed effects of 5-aminolaevulinic acid (5-ALA)-based PDT on melanoma cell lines and on experimental melanomas. To mimic the clinical situation as closely as possible, metallothionein-I/ret (MT-ret) mice, a transgenic model of skin melanoma development, were used. Optimal doses of 5-ALA as well as energy doses and power densities were determined in vitro using a cell line (Mel25) established by us from a melanoma of an MT-ret transgenic mouse as well as commercially available human and mouse melanoma cell lines. Treatment with light irradiation alone had no effect. In combination with 5-ALA, however, this illumination readily induced the death of all mouse and human melanoma cell lines examined. Still, 5-ALA PDT caused only minor focal regressive changes including haemorrhages and fibrosis of MT-ret melanomas in vivo and did not significantly delay tumour growth. These results show that, even though MT-ret melanoma cells are vulnerable to 5-ALA PDT in vitro, malignant MT-ret melanomas in vivo are quite resistant to this type of therapy at doses which are highly effective in vitro.
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Affiliation(s)
- F Córdoba
- Division of Neuropathology, Institute of Pathology, University of Bern, Murtenstrasse, Bern, Switzerland
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Photodynamic therapy for Bowen's disease and squamous cell carcinoma of the skin. Photodiagnosis Photodyn Ther 2004; 1:225-30. [PMID: 25048336 DOI: 10.1016/s1572-1000(04)00048-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Photodynamic therapy involves the activation by visible light of a previously administered photosensitizing agent in order to cause tumor necrosis. Skin tumors can be treated with topical photosensitizers and thus avoiding systemic side effects. In this study we evaluate the immediate and long-term effects of photodynamic therapy (PDT), using aminolevulinic acid (ALA) as a photosensitizer and a non-laser light source, on Bowen's disease (intra-epithelial squamous cell carcinoma) and on frank squamous cell carcinoma (SCC) of the skin. METHODS ALA in cream form (20%) was topically applied on biopsy-proven Bowen's disease or SCC of the skin. The lesions were covered with occlusive and light-shielding dressing. Sixteen hours later, they were submitted to a 10-min light session using Versa-Light™, a non-laser light source (spectral output of 580-720nm and 1250-1600nm, 100J/cm(2)). The initial evaluation was done 21 days post-treatment and every 3m thereafter. Patients that did not respond to treatment after two to three sessions were referred to surgery. RESULTS Forty Bowen's disease lesions (24 patients) and 43 SCC lesions (18 patients) underwent treatment. Median follow-up was 21±8m. No patient had any remarkable side effects. Thirty-four Bowen's disease (85%) lesions completely responded as did 32 SCC lesions (74%). CONCLUSIONS Our findings showed that PDT is highly effective in treating Bowen's disease and SCC lesions and can be used as a first treatment modality in so far as its use does not preclude the subsequent surgery recommended for the small percentage of failures.
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Juzenas P, Juzeniene A, Stakland S, Iani V, Moan J. Photosensitizing effect of protoporphyrin IX in pigmented melanoma of mice. Biochem Biophys Res Commun 2002; 297:468-72. [PMID: 12270116 DOI: 10.1016/s0006-291x(02)02238-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
No fluorescence of protoporphyrin IX (PpIX) was measured using a fiber optic probe in pigmented B16F10 melanoma in mice after topical application of 5-aminolevulinic acid methylester (ALA-Me). However, chemical extraction of tissues excised from mice after intratumoral administration of ALA-Me or its parent compound ALA revealed that this tumor had the capability to produce PpIX. Small amounts of endogenous porphyrins, mainly PpIX, were found in the melanoma not treated with these drugs. Topical application of ALA-Me followed by exposure with laser light (633nm) delayed the growth of the tumors slightly. Light alone also had a significant effect on the tumor growth.
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Affiliation(s)
- Petras Juzenas
- Department of Biophysics, Institute for Cancer Research, The Norwegian Radium Hospital, NO-0310 Montebello, Oslo, Norway.
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Edrei R, Kimel S. Oxygen depletion during in vitro photodynamic therapy: structure-activity relationships of sulfonated aluminum phthalocyanines. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1999; 50:197-203. [PMID: 10577051 DOI: 10.1016/s1011-1344(99)00092-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Photodynamically induced oxygen depletion has been measured in an Ehrlich ascites mouse tumor cell line using a Clark-type electrode. Cells are loaded with aluminum phthalocyanines, sulfonated to different degrees (A1PcS(n), n = 0,2,3,4) and consisting of various isomeric species. Different cell lines and incubation procedures are used in order to investigate the cellular uptake mechanism. Uptake (in units of molecules/cell), post-irradiation redistribution and A1PcS(n) photodegradation are measured using spectroscopic techniques. For a given sensitizer, the oxygen depletion rate per cell increases sublinearly with uptake and superlinearly with cell density. In order to compare oxygen depletion rates of different compounds, we have defined the biological quantum yield (BQY) as the number of oxygen molecules that disappear per absorbed photon. The BQY is independent of uptake and cell density; therefore, it denotes the intrinsic photoactivity of a sensitizer. Sensitizers with high BQY show efficient post-irradiation intracellular redistribution. Photodegradation during irradiation is similar for all sensitizers (20-30%).
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Affiliation(s)
- R Edrei
- Department of Chemistry, Technion-Israel Institute of Technology, Haifa, Israel
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