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Céspedes MA, Saénz DA, Calvo GH, González M, MacRobert AJ, Battah S, Casas AG, Di Venosa GM. Apoptotic cell death induced by dendritic derivatives of aminolevulinic acid in endothelial and foam cells co-cultures. Photochem Photobiol Sci 2021; 20:489-499. [PMID: 33825180 DOI: 10.1007/s43630-021-00025-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 02/12/2021] [Indexed: 11/27/2022]
Abstract
Photodynamic therapy (PDT) is an effective procedure for the treatment of lesions diseases based on the selectivity of a photosensitising compound with the ability to accumulate in the target cell. Atherosclerotic plaque is a suitable target for PDT because of the preferential accumulation of photosensitisers in atherosclerotic plaques. Dendrimers are hyperbranched polymers conjugated to drugs. The dendrimers of ALA hold ester bonds that inside the cells are cleaved and release ALA, yielding PpIX production. The dendrimer 6m-ALA was chosen to perform this study since in previous studies it induced the highest porphyrin macrophage: endothelial cell ratio (Rodriguez et al. in Photochem Photobiol Sci 14:1617-1627, 2015). We transformed Raw 264.7 macrophages to foam cells by exposure to oxidised LDLs, and we employed a co-culture model of HMEC-1 endothelial cells and foam cells to study the affinity of ALA dendrimers for the foam cells. In this work it was proposed an in vitro model of atheromatous plaque, the aim was to study the selectivity of an ALA dendrimer for the foam cells as compared to the endothelial cells in a co-culture system and the type of cell death triggered by the photodynamic treatment. The ALA dendrimer 6m-ALA showed selectivity PDT response for foam cells against endothelial cells. A light dose of 1 J/cm2 eliminate foam cells, whereas less than 50% of HMEC-1 is killed, and apoptosis cell death is involved in this process, and no necrosis is present. We propose the use of ALA dendrimers as pro-photosensitisers to be employed in photoangioplasty to aid in the treatment of obstructive cardiovascular diseases, and these molecules can also be employed as a theranostic agent.
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Affiliation(s)
- Mariela A Céspedes
- Centro de Investigaciones Sobre Porfirinas y Porfirias (CIPYP), Hospital de Clínicas José de San Martin, Universidad de Buenos Aires and CONICET, Avenida Córdoba 2351, 1er subsuelo, 1120 AAF, Autonomous City of Buenos Aires, Argentina
| | - Daniel A Saénz
- Centro de Investigaciones Sobre Porfirinas y Porfirias (CIPYP), Hospital de Clínicas José de San Martin, Universidad de Buenos Aires and CONICET, Avenida Córdoba 2351, 1er subsuelo, 1120 AAF, Autonomous City of Buenos Aires, Argentina
| | - Gustavo H Calvo
- Centro de Investigaciones Sobre Porfirinas y Porfirias (CIPYP), Hospital de Clínicas José de San Martin, Universidad de Buenos Aires and CONICET, Avenida Córdoba 2351, 1er subsuelo, 1120 AAF, Autonomous City of Buenos Aires, Argentina
| | - Marina González
- Facultad de Ciencias Médicas, Centro Científico Tecnológico La Plata, Instituto de Investigaciones Bioquímica de La Plata (INIBIOLP), Universidad Nacional de La Plata, Calle 60 y 120 s/n, 1900, La Plata, Argentina
| | - Alexander J MacRobert
- Division of Surgery and Interventional Science, University College London, London, UK
| | - Sinan Battah
- The School of Life Sciences, University of Essex, Colchester, CO4 3SQ, UK
| | - Adriana G Casas
- Centro de Investigaciones Sobre Porfirinas y Porfirias (CIPYP), Hospital de Clínicas José de San Martin, Universidad de Buenos Aires and CONICET, Avenida Córdoba 2351, 1er subsuelo, 1120 AAF, Autonomous City of Buenos Aires, Argentina.
| | - Gabriela M Di Venosa
- Centro de Investigaciones Sobre Porfirinas y Porfirias (CIPYP), Hospital de Clínicas José de San Martin, Universidad de Buenos Aires and CONICET, Avenida Córdoba 2351, 1er subsuelo, 1120 AAF, Autonomous City of Buenos Aires, Argentina.
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Abstract
AbstractPancreatic cancer has long been a leading cause of cancer death. Few patients are suitable for surgery and for those who are not, the response to treatment is generally poor. No more than about 10% survive for more than a year. Recent research has focused on focal treatment for local disease control. This review covers the development of one of the most promising options, photodynamic therapy (PDT).This review covers pre-clinical and clinical studies. Laboratory work was designed to understand the effect of PDT on the normal pancreas and surrounding tissues and on transplanted cancers in the hamster pancreas to ensure safety prior to clinical application. Essentially all clinical studies have been undertaken in University College Hospital, London. Phase-I studies used the photosensitisers mTHPC and verteporfin in patients with localised but inoperable cancers.Laboratory results showed that normal pancreas, bile duct, liver, stomach and major blood vessels could tolerate PDT without any unacceptable effects on the structure and function of these organs. Necrosis that healed safely was documented in transplanted cancers. The clinical trials showed that focal necrosis could be produced in inoperable cancers with acceptable levels of complications, but considerable refinements of treatment delivery and monitoring are required before the technique will be ready for assessment in controlled clinical trials.PDT is showing promise for the minimally invasive treatment of localised pancreatic cancers, but it is still at an early stage of development. Much more work will be necessary to optimise techniques for applying PDT to these cancers and for combining it with other therapeutic options such as chemotherapy.
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Rodriguez L, Vallecorsa P, Battah S, Di Venosa G, Calvo G, Mamone L, Sáenz D, Gonzalez MC, Batlle A, MacRobert AJ, Casas A. Aminolevulinic acid dendrimers in photodynamic treatment of cancer and atheromatous disease. Photochem Photobiol Sci 2015; 14:1617-27. [DOI: 10.1039/c5pp00126a] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
ALA dendrimers are taken up by caveolae-mediated endocytosis in macrophages. Intracellular ALA release gives rise to PpIX synthesis and subsequent photosensitization of key cells in atheromas and tumour diseases.
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Affiliation(s)
- L. Rodriguez
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP). CONICET-Htal de Clínicas Gral. José de San Martín
- Ciudad de Buenos Aires
- Argentina
| | - P. Vallecorsa
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP). CONICET-Htal de Clínicas Gral. José de San Martín
- Ciudad de Buenos Aires
- Argentina
| | - S. Battah
- School of Biological Sciences
- University of Essex
- Wivenhoe Park CO4 3SQ
- UK
- Division of Surgery and Interventional Sciences and UCL Institute of Biomedical Engineering
| | - G. Di Venosa
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP). CONICET-Htal de Clínicas Gral. José de San Martín
- Ciudad de Buenos Aires
- Argentina
| | - G. Calvo
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP). CONICET-Htal de Clínicas Gral. José de San Martín
- Ciudad de Buenos Aires
- Argentina
| | - L. Mamone
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP). CONICET-Htal de Clínicas Gral. José de San Martín
- Ciudad de Buenos Aires
- Argentina
| | - D. Sáenz
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP). CONICET-Htal de Clínicas Gral. José de San Martín
- Ciudad de Buenos Aires
- Argentina
| | - M. C. Gonzalez
- Facultad de Ciencias Médicas
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP)
- CONICET-UNLP
- Argentina
| | - A. Batlle
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP). CONICET-Htal de Clínicas Gral. José de San Martín
- Ciudad de Buenos Aires
- Argentina
| | - A. J. MacRobert
- Division of Surgery and Interventional Sciences and UCL Institute of Biomedical Engineering
- University College London
- London W1W 7EJ
- UK
| | - A. Casas
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP). CONICET-Htal de Clínicas Gral. José de San Martín
- Ciudad de Buenos Aires
- Argentina
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Peng C, Li Y, Liang H, Cheng J, Li Q, Sun X, Li Z, Wang F, Guo Y, Tian Z, Yang L, Tian Y, Zhang Z, Cao W. Detection and photodynamic therapy of inflamed atherosclerotic plaques in the carotid artery of rabbits. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2010; 102:26-31. [PMID: 20875747 DOI: 10.1016/j.jphotobiol.2010.09.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2010] [Revised: 08/22/2010] [Accepted: 09/02/2010] [Indexed: 11/29/2022]
Abstract
Photodynamic therapy (PDT) has been applied in the treatment of artery restenosis following balloon injury. This study aimed to detect the accumulation of 5-aminolevulinic acid (ALA)-derived protoporphyrin IX (PpIX) in inflamed atherosclerotic plaque in rabbit model and evaluate the efficacy of PDT. The inflamed atherosclerotic plaque in the common carotid artery was produced by combination of balloon denudation injury and high cholesterol diet. After intravenous administration of ALA, the fluorescence of PpIX in plaque was detected. At the peak time, the correlation between the fluorescence intensity of PpIX and the macrophage infiltration extent in plaque was analyzed. Subsequently, PDT (635nm at 50J/cm(2)) on the atherosclerotic plaques (n=48) was performed and its effect was evaluated by histopathology and immunohistochemistry. The fluorescence intensity of PpIX in the plaque reached the peak 2h after injection and was 12 times stronger than that of adjacent normal vessel segment, and has a positive correlation with the macrophage content (r=0.794, P<0.001). Compared with the control group, the plaque area was reduced by 59% (P<0.001) at 4week after PDT, the plaque macrophage content decreased by 56% at 1week and 64% at 4week respectively, the smooth muscle cells (SMCs) was depleted by 24% at 1week (P<0.05) and collagen content increased by 44% at 4week (P<0.05). It should be pointed out that the SMC content increased by 18% after PDT at 4week compared with that at 1week (P<0.05). Our study demonstrated that the ALA-derived PpIX can be detected to reflect the macrophage content in the plaque. ALA mediated PDT could reduce macrophage content and inhibit plaque progression, indicating a promising approach to treat inflamed atherosclerotic plaques.
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Affiliation(s)
- Chenghai Peng
- Department of Cardiology, The Second Affiliated Hospital, Harbin Medical University, Harbin 150086, PR China
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Waksman R, McEwan PE, Moore TI, Pakala R, Kolodgie FD, Hellinga DG, Seabron RC, Rychnovsky SJ, Vasek J, Scott RW, Virmani R. PhotoPoint Photodynamic Therapy Promotes Stabilization of Atherosclerotic Plaques and Inhibits Plaque Progression. J Am Coll Cardiol 2008; 52:1024-32. [DOI: 10.1016/j.jacc.2008.06.023] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2008] [Revised: 06/04/2008] [Accepted: 06/06/2008] [Indexed: 10/21/2022]
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Mitton D, Ackroyd R. A brief overview of photodynamic therapy in Europe. Photodiagnosis Photodyn Ther 2008; 5:103-11. [DOI: 10.1016/j.pdpdt.2008.04.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Revised: 04/22/2008] [Accepted: 04/23/2008] [Indexed: 10/21/2022]
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Heckenkamp J, Mellander S, Fogelstrand P, Breuer S, Brunkwall J, Mattsson E. Photodynamic Therapy Reduces Intimal Hyperplasia in Prosthetic Vascular Bypass Grafts in a Pig Model. Eur J Vasc Endovasc Surg 2007; 34:333-9. [PMID: 17513141 DOI: 10.1016/j.ejvs.2007.04.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2007] [Accepted: 04/01/2007] [Indexed: 11/28/2022]
Abstract
BACKGROUND Bypass surgery has a failing frequency of 30% during the first year, mainly due to intimal hyperplasia (IH). This negative effect is most pronounced in artificial grafts. Photodynamic therapy (PDT) is a technique in which light activates photosensitizer dyes to produce free-radicals resulting in an eradication of cells in the vascular wall. The aim of this study was to determine the effectiveness of PDT to reduce IH in a preclinical porcine PTFE bypass model. MATERIAL AND METHODS Ten pigs were used. After a pilot PDT dosimetry study (n=3) PTFE grafts were bilaterally placed into the circulation as bypasses from the common to the external iliac arteries (n=7). The right sides served as controls (C). Before implantation of the left grafts, the arterial connecting sites of the left distal anastomoses were PDT-treated. The arteries were pressurized at 180 mmHg for 5 minutes with the photosensitizer Methylene Blue (330 microg/ml), and thereafter endoluminally irradiated with laser light (lambda = 660 nm, 100 mW/cm(2), 150 J/cm(2)). After 4 weeks the specimens were retrieved and formalin fixed. Cross sections through the midportions of the distal anastomoses and the grafts were used for histology, immunohistochemistry to identify inflammatory cells and morphometric evaluation (n=7). RESULTS No systemic side effects and no graft occlusions were noted. PDT-treated anastomoses showed reduced IH in the mid-portions of the anastomoses (Area of IH: microm(2)/microm graft: C: 6970+/-1536, PDT: 2734+/-2560; P<0.005) as well as in the grafts (C: 5391+/-4031, PDT: 777+/-1331; P<0.02). The number of inflammatory cells per microscopic field was increased after PDT (C: 24+/-16, PDT: 37+/-15; P<0.009). CONCLUSIONS Adjuvant PDT, performed in an endovascular fashion, was a safe method to reduce prosthetic graftstenosis in a preclinical setting. This study underscores the clinical potential of PDT to inhibit the development of clinical bypass graftstenosis.
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Affiliation(s)
- J Heckenkamp
- Division of Vascular Surgery, Department of Vascular and Visceral Surgery, University of Cologne, Cologne, Germany.
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Fungaloi P, Waterman P, Nigri G, Statius-van Eps R, Sluiter W, Van Urk H, LaMuraglia G. Photochemically Modulated Endothelial Cell Thrombogenicity via the Thrombomodulin-Tissue Factor Pathway¶. Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2003)0780475pmectv2.0.co2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Waksman R, Leitch IM, Roessler J, Yazdi H, Seabron R, Tio F, Scott RW, Grove RI, Rychnovsky S, Robinson B, Pakala R, Cheneau E. Intracoronary photodynamic therapy reduces neointimal growth without suppressing re-endothelialisation in a porcine model. Heart 2006; 92:1138-44. [PMID: 16399853 PMCID: PMC1861129 DOI: 10.1136/hrt.2005.073486] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/20/2005] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVE To examine the effects of intracoronary PhotoPoint photodynamic therapy (PDT) with a new photosensitiser, MV0611, in the overstretch balloon and stent porcine models of restenosis. METHODS 28 pigs were injected with 3 mg/kg of MV0611 systemically 4 h before the procedure. Animals were divided into either the balloon overstretch injury (BI) group (n = 19) or the stented group (n = 9). After BI, a centred delivery catheter was positioned in the artery to cover the injured area, and light (532 nm, 125 J/cm(2)) was applied to activate the drug (n = 10). Control arteries (n = 9) were not activated by light. In the stented group, the drug was light activated before stent deployment. Serial sections of vessels were processed 14 days after treatment in the BI group and 30 days after treatment in the stented group for histomorphometric or immunohistochemical analysis. RESULTS Intracoronary PDT significantly reduced intimal thickness in both BI and stented arteries (about 65%: 0.22 (SEM 0.05) mm v 0.62 (0.05) mm, p < 0.01; and about 26%: 0.40 (0.04) mm v 0.54 (0.04) mm, p < 0.01, respectively). PDT increased luminal area by CONCLUSION Intracoronary PhotoPoint PDT with MV0611 reduces intimal proliferation without suppressing re-endothelialisation in a porcine model of restenosis.
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Affiliation(s)
- R Waksman
- Division of Cardiology, Washington Hospital Center, Washington, DC, USA.
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10
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Mitton D, Ackroyd R. History of photodynamic therapy in Great Britain. Photodiagnosis Photodyn Ther 2005; 2:239-46. [DOI: 10.1016/s1572-1000(05)00111-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2005] [Accepted: 10/26/2005] [Indexed: 10/25/2022]
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Pai M, Jamal W, Mosse A, Bishop C, Bown S, McEwan J. Inhibition of in-stent restenosis in rabbit iliac arteries with photodynamic therapy. Eur J Vasc Endovasc Surg 2005; 30:573-81. [PMID: 16125418 DOI: 10.1016/j.ejvs.2005.07.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2005] [Accepted: 07/05/2005] [Indexed: 11/18/2022]
Abstract
OBJECTIVES Photodynamic therapy (PDT, the combination of light with a photosensitising drug in the presence of oxygen) inhibits restenosis after angioplasty without stenting. This study assesses the potential of PDT for prevention of in-stent re-stenosis. DESIGN AND METHODS Normal rabbits were given the photosensitising agent 5-aminolaevulinic acid (ALA) 60 mg/kg, 3 h prior to endovascular illumination of the iliac artery (635 nm at 50 J/cm(2)) either immediately before or after deployment of an oversized (3 mm diameter) stent. PDT treated arteries were retrieved 3 or 28 days later and assessed for cell counts and vascular morphometry. Control arteries (stent but no PDT) were examined at 28 days. RESULTS There were no adverse events and all vessels were patent at the end of the study. At 3 days there was almost complete medial cell ablation when light was delivered before stent deployment (17+/-1 cells/hpf), with little effect when illumination followed stent deployment (184+/-17 cells/hpf, p<0.0001). Twenty-eight days after PDT, the neointimal areas were 1.41+/-0.52 mm(2) (stent with no PDT), 1.24+/-0.54 mm(2) (light after stent) and 0.60+/-0.21 mm(2) (light before stent) (p=0.004). CONCLUSIONS PDT before stent deployment caused almost complete medial cell ablation at 3 days with inhibition of in-stent restenosis at 28 days. PDT is worthy of further study as an adjuvant to percutaneous intervention in patients with vascular disease.
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MESH Headings
- Aminolevulinic Acid/administration & dosage
- Aminolevulinic Acid/therapeutic use
- Animals
- Arterial Occlusive Diseases/surgery
- Blood Vessel Prosthesis Implantation/instrumentation
- Disease Models, Animal
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/pathology
- Graft Occlusion, Vascular/drug therapy
- Graft Occlusion, Vascular/pathology
- Iliac Artery
- Injections, Intra-Arterial
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/pathology
- Photochemotherapy/methods
- Photosensitizing Agents/administration & dosage
- Photosensitizing Agents/therapeutic use
- Prosthesis Failure
- Rabbits
- Stents
- Treatment Outcome
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Affiliation(s)
- M Pai
- The Royal Free and University College London Medical School, London, UK
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Lilge L, Vesselov L, Whittington W. Thin cylindrical diffusers in multimode Ge-doped silica fibers. Lasers Surg Med 2005; 36:245-51. [PMID: 15704158 DOI: 10.1002/lsm.20150] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND OBJECTIVES Cylindrical fiber diffusers are common tools in photodynamic therapy (PDT). However, large outer diameter and short length limit the indications to which they can be applied. Here a diffuser with an outer diameter of 250 microm and an active length exceeding 5 cm was developed. STUDY DESIGN/MATERIALS AND METHODS Diffusers based on photosensitive quartz optical fibers with a cladding diameter of 140 microm were developed using a structured beam from an excimer laser. A complete set of photometric characteristics, including longitudinal, polar, and azimuth radiance emission diagrams were collected. RESULTS AND CONCLUSIONS The longitudinal radiance emission is homogenous to within +/-10%. The ability to create custom designed longitudinal emission profiles was demonstrated. The variations of the polar and azimuth radiance emission diagrams were within +/- 15% from an ideal Lambertian emitter. The polar uniformity can be improved with a slight increase of the outer diameter using a diffusing recoating compound. The residual light leakage at the distal end of the fiber diffuser was suppressed to 2%. The minimal bending radius after recoating is approximately 5 mm. Maximum power distribution is > 0.5 W cm(-1).
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Affiliation(s)
- Lothar Lilge
- University Health Network, 610 University Avenue, Toronto, Ontario, Canada, M5G 2M9.
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Abstract
Photodynamic therapy (PDT) is an emerging field that uses light-activated drugs to produce specific biological effects in cells and tissues. Its particular strengths arise from the ability to spatially localize the biological responses by the way the light is applied; the range of possible mechanisms of action at the cell, tissue, and organism levels; and the combination of novel molecular and optical technologies. This paper presents the basic principles of PDT and considers some of the possible applications in regenerative medicine.
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Affiliation(s)
- Brian C Wilson
- Department of Medical Biophysics, Ontario Cancer Institute/University Health Network, 610 University Avenue, Rm 7-417, Toronto, Ontario M5G 2M9, Canada.
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Fungaloi P, Waterman P, Nigri G, Statius-van Eps R, Sluiter W, van Urk H, LaMuraglia G. Photochemically Modulated Endothelial Cell Thrombogenicity via the Thrombomodulin–Tissue Factor Pathway¶. Photochem Photobiol 2003; 78:475-80. [PMID: 14653579 DOI: 10.1562/0031-8655(2003)078<0475:pmectv>2.0.co;2] [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: 11/19/2022]
Abstract
Photodynamic therapy (PDT) is based on a photochemical reaction using a photosensitizer and light to produce reactive oxygen species that have biological effects. Although its application in some fields is largely based on thrombosis, in the vascular setting thrombosis must be prevented. In this study we examined the effects of PDT on the changes in activity of thrombomodulin (TM) and tissue factor (TF) as important regulators of the coagulation process of endothelial cells. Human umbilical vein endothelial cells were treated with PDT (chloro-aluminum-sulfonated phthalocyanine, lambda = 630 nm) at different light-energy doses, and TM and TF levels were measured using fluorescence spectroscopy. Microparticles (MP) were analyzed using flow cytometry analysis. PDT alters the thrombogenic state of endothelial cells by causing decreased expression of TM and increased expression of functional TF in a light-energy dose-dependent way. PDT-treated endothelial cells shed large numbers of MP containing high levels of TF. TF functionality of PDT-treated cells, measured by a Factor Xa-generating assay, was high. TF was located mostly intracellularly and in MP. The disturbed anticoagulant balance described in this study may explain the occurrence of thrombosis induced by PDT and, if not contained, dispute the suitability of PDT as an adjuvant modality to treat vascular restenosis.
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Affiliation(s)
- Patrick Fungaloi
- Division of Vascular Surgery, Atrium Medical Center, Heerlen, The Netherlands.
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