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Ser J, Lee JY, Kim YH, Cho H. Enhanced Efficacy of Photodynamic Therapy by Coupling a Cell-Penetrating Peptide with Methylene Blue. Int J Nanomedicine 2020; 15:5803-5811. [PMID: 32821102 PMCID: PMC7418162 DOI: 10.2147/ijn.s254881] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 07/21/2020] [Indexed: 01/19/2023] Open
Abstract
Introduction Photodynamic therapy (PDT), which induces tissue damage by exposing tissue to a specific wavelength of light in the presence of a photosensitizer and oxygen, is a promising alternative treatment that could be used as an adjunct to chemotherapy and surgery in oncology. Cell-penetrating peptides (CPPs) with high arginine content, such as protamine, have membrane translocation and lysosome localization activities. They have been used in an extensive range of drug delivery applications. Methods We conjugated cell-penetrating peptides (CPPs) with methylene blue (MB) and then purification by FPLC. Synthesis structure was characterized by the absorbance spectrum, FPLC, Maldi-TOF, and then evaluated cell viability by cytotoxicity assay after photodynamic therapy (PDT) assay. An uptake imaging assay was used to determine the sites of MB and MB-Pro in subcellular compartments. Results In vitro assays showed that MB-Pro has more efficient photodynamic activities than MB alone for the colon cancer cells, owing to lysosome rupture causing the rapid necrotic cell death. In this study, we coupled protamine with MB for high efficacy PDT. The conjugates localized in the lysosomes and enhanced the efficiency of PDT by inducing necrotic cell death, whereas PDT with non-coupled MB resulted in only apoptotic processes. Discussion Our research aimed to enhance PDT by engineering the photosensitizers using CPPs coupled with methylene blue (MB). MB alone permeates through the cell membrane and distributes into the cytoplasm, whereas coupling of MB dye with CPPs localizes the MB through an endocytic mechanism to a specific organelle where the localized conjugates enhance the generation of reactive oxygen species (ROS) and induce cell damage.
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Affiliation(s)
- Jinhui Ser
- School of Materials Science & Engineering, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Ji Yeon Lee
- Department of Anesthesiology and Pain Medicine, Gachon University, Gil Medical Center, Incheon 21565, Republic of Korea
| | - Yong Ho Kim
- Gachon Pain Center and Department of Physiology, College of Medicine, Gachon University, Incheon 21999, Republic of Korea
| | - Hoonsung Cho
- School of Materials Science & Engineering, Chonnam National University, Gwangju 61186, Republic of Korea
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Pasula RR, Kuniyil A, Lim S. Molecular Entrapment in Thermophilic Ferritin for Nanoformulation in Photodynamic Therapy. ADVANCED THERAPEUTICS 2020. [DOI: 10.1002/adtp.201900172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Rupali Reddy Pasula
- School of Chemical and Biomedical EngineeringNanyang Technological University 70 Nanyang Drive 637457 Singapore
| | - Ambili Kuniyil
- School of Chemical and Biomedical EngineeringNanyang Technological University 70 Nanyang Drive 637457 Singapore
| | - Sierin Lim
- School of Chemical and Biomedical EngineeringNanyang Technological University 70 Nanyang Drive 637457 Singapore
- NTU‐Northwestern Institute for NanomedicineNanyang Technological University 50 Nanyang Drive 637553 Singapore
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Pacheco PAF, Ferreira LBG, Mendonça L, Ferreira DNM, Salles JP, Faria RX, Teixeira PCN, Alves LA. P2X7 receptor as a novel drug delivery system to increase the entrance of hydrophilic drugs into cells during photodynamic therapy. J Bioenerg Biomembr 2016; 48:397-411. [PMID: 27422545 DOI: 10.1007/s10863-016-9668-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 06/24/2016] [Indexed: 11/28/2022]
Abstract
The second-generation photosensitizer methylene blue (MB) exhibits photochemical and photophysical properties suitable for photodynamic therapy (PDT)-based cancer treatment. However, the clinical application of MB is limited because of its high hydrophilicity, which hinders its penetration into tumor tissues. Therefore, new methods to improve the entry of MB into the cytoplasm of target cells are necessary. Because MB has a mass of 319 Da, transient pores on the plasma membrane, such as the pore induced by the P2X7 receptor (P2X7R) that allows the passage of molecules up to 900 Da, could be used. Using MTT viability assays, flow cytometry experiments, and fluorescence microscopy, we evaluated the toxicity and phototoxicity of MB and potentiation effects of ATP and MB on cell death processes in the J774 cell line (via a P2X7-associated pore). We observed that treatment with 5 μM MB for 15 min promoted the rate of entry of MB into the cytoplasm to 4.7 %. However, treatment with 5 μM MB and 1 mM ATP for the same amount of time increased this rate to 90.2 %. However, this effect was inhibited by pretreatment with a P2X7 antagonist. We used peritoneal macrophages and a cell line that does not express P2X7R as controls. These cells were more resistant to PDT with MB under the same experimental conditions. Taken together, these results suggest the use of the pore associated with P2X7R as a drug delivery system to increase the passage of hydrophilic drugs into cells that express this receptor, thus facilitating PDT.
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Affiliation(s)
| | | | - Leonardo Mendonça
- Laboratório de Comunicação Celular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brasil
| | - Dinarte Neto M Ferreira
- Laboratório de Comunicação Celular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brasil
| | - Juliana Pimenta Salles
- Laboratório de Toxoplasmose, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz - FIOCRUZ, Av. Brasil, 4365 Manguinhos - CEP, :21045-900, Rio de Janeiro, RJ, Brasil
| | - Robson Xavier Faria
- Laboratório de Toxoplasmose, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz - FIOCRUZ, Av. Brasil, 4365 Manguinhos - CEP, :21045-900, Rio de Janeiro, RJ, Brasil.
| | | | - Luiz Anastacio Alves
- Laboratório de Comunicação Celular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brasil
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Screening and In Vitro Evaluation of Mucoadhesive Thermoresponsive System Containing Methylene Blue for Local Photodynamic Therapy of Colorectal Cancer. Pharm Res 2015; 33:776-91. [DOI: 10.1007/s11095-015-1826-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 11/03/2015] [Indexed: 12/22/2022]
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Johansson A, Palte G, Schnell O, Tonn JC, Herms J, Stepp H. 5-Aminolevulinic acid-induced protoporphyrin IX levels in tissue of human malignant brain tumors. Photochem Photobiol 2010; 86:1373-8. [PMID: 20854414 DOI: 10.1111/j.1751-1097.2010.00799.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Protoporphyrin IX (PpIX) produced from exogenous, orally administered 5-aminolevulinic acid (ALA) displays high tumor-selective uptake and is being successfully employed for fluorescence-guided resection (FGR) of human malignant gliomas. Furthermore, the phototoxicity of PpIX can be utilized for photodynamic therapy (PDT) of brain tumors, which has been shown previously. Here, the absolute PpIX concentration in human brain tissue was investigated following oral ALA administration (20 mg kg(-1) b.w.). An extraction procedure was used to quantify PpIX in macroscopic tissue samples, weighing 0.013-0.214 g, obtained during FGR. The PpIX concentration was significantly higher in vital grade IV tumors (5.8 ± 4.8 μm, mean ± SD, range 0-28.2 μm, n = 8) as compared with grade III tumors (0.2 ± 0.4 μm, mean ± SD, range 0-0.9 μm, n = 4). There was also a large heterogeneity within grade IV tumors with PpIX displaying significantly lower levels in infiltration zones and necrotic regions as compared with vital tumor parts. The average PpIX concentration in vital grade IV tumor parts was in the range previously shown sufficient for PDT-induced tissue damage following irradiation. However, the feasibility of PDT for grade III brain tumors and for grade IV brain tumors displaying mainly necrotic tissue areas without solid tumor parts needs to be further investigated.
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Affiliation(s)
- Ann Johansson
- Laser-Forschungslabor, University Clinic Großhadern, Munich, Germany.
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Bisland SK, Lilge L, Lin A, Rusnov R, Wilson BC. Metronomic Photodynamic Therapy as a New Paradigm for Photodynamic Therapy: Rationale and Preclinical Evaluation of Technical Feasibility for Treating Malignant Brain Tumors¶. Photochem Photobiol 2007. [DOI: 10.1111/j.1751-1097.2004.tb00044.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Tardivo JP, Del Giglio A, de Oliveira CS, Gabrielli DS, Junqueira HC, Tada DB, Severino D, de Fátima Turchiello R, Baptista MS. Methylene blue in photodynamic therapy: From basic mechanisms to clinical applications. Photodiagnosis Photodyn Ther 2005; 2:175-91. [PMID: 25048768 DOI: 10.1016/s1572-1000(05)00097-9] [Citation(s) in RCA: 507] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2005] [Revised: 09/09/2005] [Accepted: 09/12/2005] [Indexed: 02/01/2023]
Abstract
Methylene blue (MB) is a molecule that has been playing important roles in microbiology and pharmacology for some time. It has been widely used to stain living organisms, to treat methemoglobinemia, and lately it has been considered as a drug for photodynamic therapy (PDT). In this review, we start from the fundamental photophysical, photochemical and photobiological characteristics of this molecule and evolved to show in vitro and in vivo applications related to PDT. The clinical cases shown include treatments of basal cell carcinoma, Kaposi's Sarcoma, melanoma, virus and fungal infections. We concluded that used together with a recently developed continuous light source (RL50(®)), MB has the potential to treat a variety of cancerous and non-cancerous diseases, with low toxicity and no side effects.
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Affiliation(s)
- João Paulo Tardivo
- Faculdade de Medicina ABC, Av. Príncipe de Gales, 821, C.P. 106, CEP 09060-650, Brazil
| | - Auro Del Giglio
- Faculdade de Medicina ABC, Av. Príncipe de Gales, 821, C.P. 106, CEP 09060-650, Brazil
| | | | | | | | - Dayane Batista Tada
- Departamento de Bioquímica, IQ-USP, C.P. 26077, 05513-970 São Paulo, SP, Brazil
| | - Divinomar Severino
- Departamento de Bioquímica, IQ-USP, C.P. 26077, 05513-970 São Paulo, SP, Brazil
| | | | - Mauricio S Baptista
- Departamento de Bioquímica, IQ-USP, C.P. 26077, 05513-970 São Paulo, SP, Brazil
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Bisland SK, Lilge L, Lin A, Rusnov R, Wilson BC. Metronomic photodynamic therapy as a new paradigm for photodynamic therapy: rationale and preclinical evaluation of technical feasibility for treating malignant brain tumors. Photochem Photobiol 2004; 80:22-30. [PMID: 15339204 DOI: 10.1562/2004-03-05-ra-100.1] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The concept of metronomic photodynamic therapy (mPDT) is presented, in which both the photosensitizer and light are delivered continuously at low rates for extended periods of time to increase selective tumor cell kill through apoptosis. The focus of the present preclinical study is on mPDT treatment of malignant brain tumors, in which selectivity tumor cell killing versus damage to normal brain is critical. Previous studies have shown that low-dose PDT using 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) can induce apoptosis in tumor cells without causing necrosis in either tumor or normal brain tissue or apoptosis in the latter. On the basis of the levels of apoptosis achieved and model calculations of brain tumor growth rates, metronomic delivery or multiple PDT treatments, such as hyperfractionation, are likely required to produce enough tumor cell kill to be an effective therapy. In vitro studies confirm that ALA-mPDT induces a higher incidence of apoptotic (terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate, sodium salt nick-end labeling positive) cells as compared with an acute, high-dose regimen (ALA-aPDT). In vivo, mPDT poses two substantial technical challenges: extended delivery of ALA and implantation of devices for extended light delivery while allowing unencumbered movement. In rat models, ALA administration via the drinking water has been accomplished at very high doses (up to 10 times therapeutic dose) for up to 10 days, and ex vivo spectrofluorimetry of tumor (9L gliosarcoma) and normal brain demonstrates a 3-4 fold increase in the tumor-to-brain ratio of PpIX concentration, without evidence of toxicity. After mPDT treatment, histological staining reveals extensive apoptosis within the tumor periphery and surrounding microinvading colonies that is not evident in normal brain or tumor before treatment. Prototype light sources and delivery devices were found to be practical, either using a laser diode or light-emitting diode (LED) coupled to an implanted optical fiber in the rat model or a directly implanted LED using a rabbit model. The combined delivery of both drug and light during an extended period, without compromising survival of the animals, is demonstrated. Preliminary evidence of selective apoptosis of tumor under these conditions is presented.
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Affiliation(s)
- Stuart K Bisland
- Ontario Cancer Institute, University Health Network, 610 University Avenue, Toronto, Ontario, Canada M5G 2M9.
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van Duijnhoven FH, Aalbers RIJM, Rovers JP, Terpstra OT, Kuppen PJK. The immunological consequences of photodynamic treatment of cancer, a literature review. Immunobiology 2003; 207:105-13. [PMID: 12675268 DOI: 10.1078/0171-2985-00221] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In this review we discuss the effect of photodynamic treatment (PDT) of solid tumors on the immune response. The effect on both the innate and adapted immune response is discussed. We have summarized the evidence that PDT causes or enhances an anti-tumor response. PDT is a local treatment in which the treated tumor remains in situ while the immune system is only locally affected and still functional in contrast with e.g. after systemic chemotherapy. We conclude that PDT of cancer is a way of in situ vaccination to induce a systemic antitumor response. In general, immune cells are found in the tumor stroma, separated from tumor cells by extracellular matrix and basal membrane-like structures. We hypothesize that PDT destroys the structure of a tumor, thereby enabling direct interaction between immune cells and tumor cells resulting in the systemic anti-tumor immune response.
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Lucroy MD, Ridgway TD, Peavy GM, Krasieva TB, Higbee RG, Campbell GA, Blaik MA. Preclinical evaluation of 5-aminolevulinic acid-based photodynamic therapy for canine transitional cell carcinoma. Vet Comp Oncol 2003; 1:76-85. [DOI: 10.1046/j.1476-5829.2003.00010.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Germann PG, Voelker FA, Cockerell G, Burkhardt JE, Ryan AM. Importance and impact of discovery pathology. EXPERIMENTAL AND TOXICOLOGIC PATHOLOGY : OFFICIAL JOURNAL OF THE GESELLSCHAFT FUR TOXIKOLOGISCHE PATHOLOGIE 2002; 54:165-7. [PMID: 12211639 DOI: 10.1078/0940-2993-00224] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Abstract
Pathologists are uniquely qualified to play a central role in driving drug discovery and development programs by: 1) establishing disease models to assess potential therapies, 2) characterizing modifications in the disease state in response to therapies, 3) characterizing toxicologic mechanisms and responses to drug candidates, and 4) facilitating multidisciplinary efforts to monitor for the clinical occurrence, progression, and reversibility of adverse events. Such nontraditional deployment of resources must, to be viable, produce benefits to the pharmaceutical industry comparable to those of more conventional activities such as delivery of data in nonclinical safety studies. Additionally, benefits must be tangible from standpoints such as time savings or improved quality of research decisions, manifesting as either program acceleration or improved candidate survival.
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Affiliation(s)
- John E Burkhardt
- Department of Drug Safety Evaluation, Pfizer Global Research and Development, Groton, CT 06340, USA.
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Hinnen P, De Rooij FW, Voortman G, Tilanus HW, Wilson JH, Siersema PD. Acrylate yellow filters in operating lights protect against photosensitization tissue damage. Br J Surg 2000; 87:231-5. [PMID: 10671933 DOI: 10.1046/j.1365-2168.2000.01325.x] [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: 11/20/2022]
Abstract
BACKGROUND Photosensitized patients are exposed to bright lights when undergoing intraoperative photodynamic therapy or fluorescence measurements. Acrylate yellow filters might reduce unwanted tissue damage. METHODS To investigate the protective value of these filters, the spectral power distribution of the operating lights and light energy densities with and without an acrylate yellow filter were measured. Subsequently the effects of light exposure on the survival of a human hepatocellular carcinoma cell line and the photodamage induced in pig tissues after the administration of 5-aminolaevulinic acid were also studied. RESULTS The light energy density in the ultraviolet and blue region of the light spectrum emitted by the operating light was reduced up to 50 per cent by the acrylate yellow filter. The survival of photosensitized cells was longer and photodamage induced in pig tissues was less when exposed to filtered light. CONCLUSION Photodamage induced by operating lights can be reduced by filtering out ultraviolet and blue light by means of acrylate yellow filters.
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Affiliation(s)
- P Hinnen
- Department of Gastroenterology and Internal Medicine II, University Hospital Rotterdam-Dijkzigt, Rotterdam, The Netherlands
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Obwegeser A, Jakober R, Kostron H. Uptake and kinetics of 14C-labelled meta-tetrahydroxyphenylchlorin and 5-aminolaevulinic acid in the C6 rat glioma model. Br J Cancer 1998; 78:733-8. [PMID: 9743291 PMCID: PMC2062980 DOI: 10.1038/bjc.1998.569] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Meta-tetrahydroxyphenylchlorin (m-THPC) and 5-aminolaevulinic acid (5-ALA) are two second-generation photosensitizers which are currently under investigation for photodynamic therapy (PDT) and photodynamic diagnosis (PDD). So far, the experience with these photosensitizers for use within brain tumours is limited. We examined the distribution and retention of 14C-labelled m-THPC and [14C]5-ALA in the rat C6 glioma brain tumour model. After intraperitoneal injection of m-THPC (71,909 d.p.m. microl(-1); 0.16 mg ml(-1) m-THPC; 0.3 mg kg(-1)), the following activities were found after 36 h: brain tumour 223,664 d.p.m. g(-1), brain contralateral to the tumour side 2567 d.p.m. g(-1), liver 369,959 d.p.m. g(-1) and skin 55,197 d.p.m. g(-1); 100,000 d.p.m. corresponding to 0.22 microg of m-THPC. After 7 days, the concentration of m-THPC decreased to 76,277 d.p.m. g(-1) in tumour and 635 d.p.m. g(-1) in brain. The radioactivity after intravenous administration of [14C]5-ALA (23,079 d.p.m. microl(-1); 40 mg ml(-1); 120 mg kg(-1)) increased within 15 min (59,634 d.p.m. g(-1) in tumour, 17,427 d.p.m. g(-1) in brain); after 8 h only a small amount (3653 d.p.m. g(-1) in tumour) remained. Brain adjacent to the tumour was also found to have a higher uptake of 5-ALA. This study provides basic information for the use of m-THPC and 5-ALA in brain tumours. Because of the different pharmacokinetic and toxicological profile, we recommend m-THPC for PDT and 5-ALA for PDD. Clinical trials now have to prove the superior phototoxic properties of these second-generation photosensitizers.
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Affiliation(s)
- A Obwegeser
- Department of Neurosurgery, University of Innsbruck, Austria
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van den Boogert J, van Hillegersberg R, de Rooij FW, de Bruin RW, Edixhoven-Bosdijk A, Houtsmuller AB, Siersema PD, Wilson JH, Tilanus HW. 5-Aminolaevulinic acid-induced protoporphyrin IX accumulation in tissues: pharmacokinetics after oral or intravenous administration. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1998; 44:29-38. [PMID: 9745726 DOI: 10.1016/s1011-1344(98)00102-x] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
UNLABELLED In this study, the biodistribution of 5-aminolaevulinic acid (ALA) and accumulation of protoporphyrin IX (PpIX) in rats have been examined. Two groups of 21 WAG/Rij rats are given 200 mg/kg ALA orally or intravenously. Six rats serve as controls. At 1, 2, 3, 4, 6, 12 and 24 h after ALA administration, ALA and porphyrin concentrations are measured in 18 tissues and fluids. Liver enzymes and renal-function tests are measured to determine ALA toxicity. In both groups ALA concentration is highest in kidney, bladder and urine. After oral administration, high concentrations are also found in duodenal aspirate and jejunum. Mild, short-lasting elevation of creatinine is seen in both treatment groups. Porphyrins, especially PpIX, accumulate mainly in duodenal aspirate, jejunum, liver and kidney (> 10 nmol/g tissue), less in oesophagus, stomach, colon, spleen, bladder, heart, lung and nerve (2-10 nmol/g tissue), and only slightly in plasma, muscle, fat, skin and brain (< 2 nmol/g tissue). In situ synthesis of porphyrins rather than enterohepatic circulation contributes to the PpIX accumulation. Confocal laser scanning microscopy shows selective porphyrin fluorescence in epithelial layers. Peak levels and total production of porphyrins are equal after oral and intravenous ALA administration. IN CONCLUSION administration of 200 mg/kg ALA results in accumulation of photosensitive concentrations of PpIX, 1 to 6 h after ALA administration, in all tissues except muscle, fat, skin and brain. Knowledge of the time-concentration relationship should be helpful in selecting dosages, routes of administration and timing of ALA photodynamic therapy.
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Affiliation(s)
- J van den Boogert
- Laboratory for Experimental Surgery, Erasmus University, Medical Faculty, Rotterdam, Netherlands.
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Peng Q, Berg K, Moan J, Kongshaug M, Nesland JM. 5-Aminolevulinic acid-based photodynamic therapy: principles and experimental research. Photochem Photobiol 1997; 65:235-51. [PMID: 9066303 DOI: 10.1111/j.1751-1097.1997.tb08549.x] [Citation(s) in RCA: 445] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Q Peng
- Department of Pathology, Norwegian Radium Hospital, University of Oslo, Norway.
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Abstract
Photodynamic therapy (PDT) is a cancer treatment based on the accumulation in malignant tissue of a photosensitiser with low systemic toxicity. Subsequent illumination induces a type II photochemical reaction with singlet oxygen production that results in destruction of biomolecules and subcellular organelles. The first full clinical report of PDT dates from 1976. Haematoporphyrin derivative, a complex mixture of porphyrins, was initially used as a photosensitiser. An enriched fraction (porfimer sodium) is now the most commonly used clinical agent. After systemic administration porphyrins bind to albumin and lipoproteins. Accumulation occurs mainly in tumours and organs of the reticuloendothelial system. The light of an argon-dye laser can be tuned to the appropriate wavelength and delivered either superficially, interstitially or intraluminally. Light distribution can be assessed by using a radiation transport model and tissue optical properties, or direct measurement with light detectors. The effects of PDT depend in a complex way on: characteristics, tissue concentration and localisation of the photosensitiser; the target tissue optical properties and oxygenation; activation wavelength, power density and treatment regimen. Future research is directed towards: better photosensitisers (i.e. phthalocyanines, chlorins or protoporphyrin IX endogenously produced from 5-aminolevulinic acid); improved light generation and delivery; and combination with hyperthermia, chemotherapy, radiotherapy or surgery. Adjuvant intraoperative PDT is a promising approach to destroying residual tumour after surgery.
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