1
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Sookai S, Perumal S, Kaur M, Munro OQ. Pt(II) Bis(pyrrole-imine) complexes: Luminescent probes and cytotoxicity in MCF-7 cells†. J Inorg Biochem 2024; 258:112617. [PMID: 38805758 DOI: 10.1016/j.jinorgbio.2024.112617] [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: 03/28/2024] [Revised: 05/20/2024] [Accepted: 05/22/2024] [Indexed: 05/30/2024]
Abstract
Four Pt(II) bis(pyrrole-imine) Schiff base chelates (1-4) were synthesised by previously reported methods, through a condensation reaction, and the novel crystal structure of 2,2'-{propane-1,3-diylbis[nitrilo(E)methylylidene]}bis(pyrrol-1-ido)platinum(II) (1) was obtained. Pt(II) complexes 1-4 exhibited phosphorescence, with increased luminescence in anaerobic solvents or when bound to human serum albumin (HSA). One of the complexes shows a 15.6-fold increase in quantum yield when bound to HSA and could be used to detect HSA concentrations as low as 5 nM. Pt(II) complexes 1-3 was investigated as potential theranostic agents in MCF-7 breast cancer cells, but only complex 3 exhibited cytotoxicity when irradiated with UV light (λ355nmExcitation). Interestingly, the cytotoxicity of complex 1 was unresponsive to UV light irradiation. This indicates that only complex 3 can be considered a potential photosensitising agent.
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Affiliation(s)
- Sheldon Sookai
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, PO WITS 2050, Johannesburg, South Africa.
| | - Shanen Perumal
- Research Unit, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg 2050, South Africa
| | - Mandeep Kaur
- Research Unit, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg 2050, South Africa
| | - Orde Q Munro
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, PO WITS 2050, Johannesburg, South Africa; School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, UK
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2
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Ibarra AMC, Aguiar EMG, Ferreira CBR, Siqueira JM, Corrêa L, Nunes FD, Franco ALDS, Cecatto RB, Hamblin MR, Rodrigues MFSD. Photodynamic therapy in cancer stem cells - state of the art. Lasers Med Sci 2023; 38:251. [PMID: 37919479 DOI: 10.1007/s10103-023-03911-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 10/14/2023] [Indexed: 11/04/2023]
Abstract
Despite significant efforts to control cancer progression and to improve oncology treatment outcomes, recurrence and tumor resistance are frequently observed in cancer patients. These problems are partly related to the presence of cancer stem cells (CSCs). Photodynamic therapy (PDT) has been developed as a therapeutic approach for solid tumors; however, it remains unclear how this therapy can affect CSCs. In this review, we focus on the effects of PDT on CSCs and the possible changes in the CSC population after PDT exposure. Tumor response to PDT varies according to the photosensitizer and light parameters employed, but most studies have reported the successful elimination of CSCs after PDT. However, some studies have reported that CSCs were more resistant to PDT than non-CSCs due to the increased efflux of photosensitizer molecules and the action of autophagy. Additionally, using different PDT approaches to target the CSCs resulted in increased sensitivity, reduction of sphere formation, invasiveness, stem cell phenotype, and improved response to chemotherapy. Lastly, although mainly limited to in vitro studies, PDT, combined with targeted therapies and/or chemotherapy, could successfully target CSCs in different solid tumors and promote the reduction of stemness, suggesting a promising therapeutic approach requiring evaluation in robust pre-clinical studies.
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Affiliation(s)
- Ana Melissa C Ibarra
- Postgraduate Program in Biophotonics Applied to Health Sciences, Nove de Julho University - UNINOVE, São Paulo, Brazil
| | | | - Cássia B R Ferreira
- Postgraduate Program in Biophotonics Applied to Health Sciences, Nove de Julho University - UNINOVE, São Paulo, Brazil
| | | | - Luciana Corrêa
- School of Dentistry, University of São Paulo - FOUSP, São Paulo, Brazil
| | - Fabio D Nunes
- School of Dentistry, University of São Paulo - FOUSP, São Paulo, Brazil
| | | | - Rebeca B Cecatto
- Postgraduate Program in Biophotonics Applied to Health Sciences, Nove de Julho University - UNINOVE, São Paulo, Brazil
| | - Michael R Hamblin
- Laser Research Centre, Faculty of Health Science, University of Johannesburg, Johannesburg, South Africa
| | - Maria Fernanda S D Rodrigues
- Postgraduate Program in Biophotonics Applied to Health Sciences, Nove de Julho University - UNINOVE, São Paulo, Brazil.
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3
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Kessel D. Photodynamic therapy: Critical PDT theory IX-Translational efforts. Photochem Photobiol 2023. [PMID: 37811552 DOI: 10.1111/php.13867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 09/27/2023] [Accepted: 09/29/2023] [Indexed: 10/10/2023]
Affiliation(s)
- David Kessel
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, Michigan, USA
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4
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Simões JCS, Sarpaki S, Papadimitroulas P, Therrien B, Loudos G. Conjugated Photosensitizers for Imaging and PDT in Cancer Research. J Med Chem 2020; 63:14119-14150. [PMID: 32990442 DOI: 10.1021/acs.jmedchem.0c00047] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Early cancer detection and perfect understanding of the disease are imperative toward efficient treatments. It is straightforward that, for choosing a specific cancer treatment methodology, diagnostic agents undertake a critical role. Imaging is an extremely intriguing tool since it assumes a follow up to treatments to survey the accomplishment of the treatment and to recognize any conceivable repeating injuries. It also permits analysis of the disease, as well as to pursue treatment and monitor the possible changes that happen on the tumor. Likewise, it allows screening the adequacy of treatment and visualizing the state of the tumor. Additionally, when the treatment is finished, observing the patient is imperative to evaluate the treatment methodology and adjust the treatment if necessary. The goal of this review is to present an overview of conjugated photosensitizers for imaging and therapy.
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Affiliation(s)
- João C S Simões
- Institute of Chemistry, University of Neuchatel, Avenue de Bellevaux 51, CH-2000 Neuchatel, Switzerland.,BioEmission Technology Solutions, Alexandras Avenue 116, 11472 Athens, Greece
| | - Sophia Sarpaki
- BioEmission Technology Solutions, Alexandras Avenue 116, 11472 Athens, Greece
| | | | - Bruno Therrien
- Institute of Chemistry, University of Neuchatel, Avenue de Bellevaux 51, CH-2000 Neuchatel, Switzerland
| | - George Loudos
- BioEmission Technology Solutions, Alexandras Avenue 116, 11472 Athens, Greece
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5
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Manda G, Hinescu ME, Neagoe IV, Ferreira LF, Boscencu R, Vasos P, Basaga SH, Cuadrado A. Emerging Therapeutic Targets in Oncologic Photodynamic Therapy. Curr Pharm Des 2019; 24:5268-5295. [DOI: 10.2174/1381612825666190122163832] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 01/18/2019] [Indexed: 12/20/2022]
Abstract
Background:Reactive oxygen species sustain tumorigenesis and cancer progression through deregulated redox signalling which also sensitizes cancer cells to therapy. Photodynamic therapy (PDT) is a promising anti-cancer therapy based on a provoked singlet oxygen burst, exhibiting a better toxicological profile than chemo- and radiotherapy. Important gaps in the knowledge on underlining molecular mechanisms impede on its translation towards clinical applications.Aims and Methods:The main objective of this review is to critically analyse the knowledge lately gained on therapeutic targets related to redox and inflammatory networks underlining PDT and its outcome in terms of cell death and resistance to therapy. Emerging therapeutic targets and pharmaceutical tools will be documented based on the identified molecular background of PDT.Results:Cellular responses and molecular networks in cancer cells exposed to the PDT-triggered singlet oxygen burst and the associated stresses are analysed using a systems medicine approach, addressing both cell death and repair mechanisms. In the context of immunogenic cell death, therapeutic tools for boosting anti-tumor immunity will be outlined. Finally, the transcription factor NRF2, which is a major coordinator of cytoprotective responses, is presented as a promising pharmacologic target for developing co-therapies designed to increase PDT efficacy.Conclusion:There is an urgent need to perform in-depth molecular investigations in the field of PDT and to correlate them with clinical data through a systems medicine approach for highlighting the complex biological signature of PDT. This will definitely guide translation of PDT to clinic and the development of new therapeutic strategies aimed at improving PDT.
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Affiliation(s)
| | | | | | - Luis F.V. Ferreira
- CQFM-Centro de Fisica Molecular and IN-Institute for Nanosciences and Nanotechnologies and IBB-Institute for Bioengineering and Biosciences, Instituto Superior Tecnico, Universidade de Lisboa, Lisbon, Portugal
| | | | - Paul Vasos
- Research Centre of the University of Bucharest, Bucharest, Romania
| | - Selma H. Basaga
- Molecular Biology Genetics & Program, Faculty of Engineering & Natural Sciences, Sabanci University, Istanbul, Turkey
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6
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Sah U, Sharma K, Chaudhri N, Sankar M, Gopinath P. Antimicrobial photodynamic therapy: Single-walled carbon nanotube (SWCNT)-Porphyrin conjugate for visible light mediated inactivation of Staphylococcus aureus. Colloids Surf B Biointerfaces 2017; 162:108-117. [PMID: 29190461 DOI: 10.1016/j.colsurfb.2017.11.046] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 10/23/2017] [Accepted: 11/16/2017] [Indexed: 12/11/2022]
Abstract
Due to the excessive use of antibiotics over the years, the microorganisms have developed resistance to numerous drugs. The growth of multi-resistant organisms (MROs) heads due to the insufficient treatment with the currently available medications which present a great threat to the biotic component of the environment as well as to the food technology sectors. The goal of this research was to develop a nano-composite made up of single-walled carbon nanotubes (SWCNTs) and amine-functionalized porphyrin, which could further be used for the anti-microbial studies in presence of visible light showing photodynamic effect to inactivate cells. Photodynamic antimicrobial chemotherapy is gaining significant interest due to its capabilities as an innovative form of antimicrobial treatment. The development of anti-microbial photodynamic therapy (a-PDT) is a non-antibiotic access to inactivate microorganisms. We examined the synthesis of amine-functionalized porphyrin and conjugated it to the oxidised single-walled carbon nanotubes (SWCNTs). By the use of appropriate amount of single-walled carbon nanotubes (SWCNTs), we have shown the interaction between the porphyrin conjugated nanotubes and the bacterial cells in presence of visible light led to the cell membrane damage, concluding that SWCNT-porphyrin conjugates can be used as an antibacterial agent. The characterization of the oxidised SWCNT and SWCNT-porphyrin conjugates was determined by field emission scanning electron microscopy (FE-SEM), which provides detailed information about the composition and the morphological analysis. The particle size measurements were carried out by transmission electron microscopy (TEM). On investigating under the florescence microscopy, red fluorescence was observed. Thus, these properties demand us to design this facile material comprised of SWCNT-aminoporphyrin conjugates that shows potent antibacterial activity.
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Affiliation(s)
- Upasana Sah
- Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, 247667, India; Centre of Excellence: Nanotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India
| | - Kajal Sharma
- Centre of Excellence: Nanotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India
| | - Nivedita Chaudhri
- Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, 247667, India
| | - Muniappan Sankar
- Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, 247667, India; Centre of Excellence: Nanotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India.
| | - P Gopinath
- Centre of Excellence: Nanotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India; Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India.
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7
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Souslova EA, Mironova KE, Deyev SM. Applications of genetically encoded photosensitizer miniSOG: from correlative light electron microscopy to immunophotosensitizing. JOURNAL OF BIOPHOTONICS 2017; 10:338-352. [PMID: 27435584 DOI: 10.1002/jbio.201600120] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 06/23/2016] [Accepted: 06/24/2016] [Indexed: 06/06/2023]
Abstract
Genetically encoded photosensitizers (PSs), e.g. ROS generating proteins, correspond to a novel class of PSs that are highly desirable for biological and medical applications since they can be used in combination with a variety of genetic engineering manipulations allowing for precise spatio-temporal control of ROS production within living cells and organisms. In contrast to the commonly used chemical PSs, they can be modified using genetic engineering approaches and targeted to particular cellular compartments and cell types. Mini Singlet Oxygen Generator (miniSOG), a small flavoprotein capable of singlet oxygen production upon blue light irradiation, was initially reported as a high contrast probe for correlative light electron microscopy (CLEM) without the need of exogenous ligands, probes or destructive permeabilizing detergents. Further miniSOG was successfully applied for chromophore-assisted light inactivation (CALI) of proteins, as well as for photo-induced cell ablation in tissue cultures and in Caenorhabditis elegans. Finally, a novel approach of immunophotosensitizing has been developed, exploiting the specificity of mini-antibodies or selective scaffold proteins and photo-induced cytotoxicity of miniSOG, which is particularly promising for selective non-invasive photodynamic therapy of cancer (PDT) due to the spatial selectivity and locality of destructive action compared to other methods of oncotherapy.
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Affiliation(s)
- Ekaterina A Souslova
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry of Russian Academy of Sciences (IBCH RAS), Miklukho-Maklaya str. 16/10, Moscow, 117997, Russia
| | - Kristina E Mironova
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry of Russian Academy of Sciences (IBCH RAS), Miklukho-Maklaya str. 16/10, Moscow, 117997, Russia
| | - Sergey M Deyev
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry of Russian Academy of Sciences (IBCH RAS), Miklukho-Maklaya str. 16/10, Moscow, 117997, Russia
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8
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Abstract
Photodynamic therapy (PDT) was discovered more than 100 years ago, and has since become a well-studied therapy for cancer and various non-malignant diseases including infections. PDT uses photosensitizers (PSs, non-toxic dyes) that are activated by absorption of visible light to initially form the excited singlet state, followed by transition to the long-lived excited triplet state. This triplet state can undergo photochemical reactions in the presence of oxygen to form reactive oxygen species (including singlet oxygen) that can destroy cancer cells, pathogenic microbes and unwanted tissue. The dual-specificity of PDT relies on accumulation of the PS in diseased tissue and also on localized light delivery. Tetrapyrrole structures such as porphyrins, chlorins, bacteriochlorins and phthalocyanines with appropriate functionalization have been widely investigated in PDT, and several compounds have received clinical approval. Other molecular structures including the synthetic dyes classes as phenothiazinium, squaraine and BODIPY (boron-dipyrromethene), transition metal complexes, and natural products such as hypericin, riboflavin and curcumin have been investigated. Targeted PDT uses PSs conjugated to antibodies, peptides, proteins and other ligands with specific cellular receptors. Nanotechnology has made a significant contribution to PDT, giving rise to approaches such as nanoparticle delivery, fullerene-based PSs, titania photocatalysis, and the use of upconverting nanoparticles to increase light penetration into tissue. Future directions include photochemical internalization, genetically encoded protein PSs, theranostics, two-photon absorption PDT, and sonodynamic therapy using ultrasound.
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9
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Managa M, Amuhaya EK, Nyokong T. Photodynamic antimicrobial chemotherapy activity of (5,10,15,20-tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III). SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 151:867-874. [PMID: 26184471 DOI: 10.1016/j.saa.2015.06.088] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Revised: 06/13/2015] [Accepted: 06/16/2015] [Indexed: 06/04/2023]
Abstract
(5,10,15,20-Tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III) (complex 1) was conjugated to platinum nanoparticles (PtNPs) (represented as 1-PtNPs). The resulting conjugate showed 18 nm red shift in the Soret band when compared to 1 alone. Complex 1 and 1-PtNPs showed promising photodynamic antimicrobial chemotherapy (PACT) activity against Staphylococcus aureus, Escherichia coli and Candida albicans in solution where the log reductions obtained were 4.92, 3.76, and 3.95, respectively for 1-PtNPs. The singlet oxygen quantum yields obtained were higher at 0.56 for 1-PtNPs in DMF while that of 1 was 0.52 in the same solvent. This resulted in improved PACT activity for 1-PtNPs compared to 1 alone.
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Affiliation(s)
- Muthumuni Managa
- Department of Chemistry, Rhodes University, Grahamstown 6140, South Africa
| | - Edith K Amuhaya
- Department of Chemistry, Rhodes University, Grahamstown 6140, South Africa
| | - Tebello Nyokong
- Department of Chemistry, Rhodes University, Grahamstown 6140, South Africa.
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10
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Rapozzi V, Della Pietra E, Bonavida B. Dual roles of nitric oxide in the regulation of tumor cell response and resistance to photodynamic therapy. Redox Biol 2015; 6:311-317. [PMID: 26319434 PMCID: PMC4556768 DOI: 10.1016/j.redox.2015.07.015] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 07/08/2015] [Accepted: 07/29/2015] [Indexed: 12/16/2022] Open
Abstract
Photodynamic therapy (PDT) against cancer has gained attention due to the successful outcome in some cancers, particularly those on the skin. However, there have been limitations to PDT applications in deep cancers and, occasionally, PDT treatment resulted in tumor recurrence. A better understanding of the underlying molecular mechanisms of PDT-induced cytotoxicity and cytoprotection should facilitate the development of better approaches to inhibit the cytoprotective effects and also augment PDT-mediated cytotoxicity. PDT treatment results in the induction of iNOS/NO in both the tumor and the microenvironment. The role of NO in cytotoxicity and cytoprotection was examined. The findings revealed that NO mediates its effects by interfering with a dysregulated pro-survival/anti-apoptotic NF-κB/Snail/YY1/RKIP loop which is often expressed in cancer cells. The cytoprotective effect of PDT-induced NO was the result of low levels of NO that activates the pro-survival/anti-apoptotic NF-κB, Snail, and YY1 and inhibits the anti-survival/pro-apoptotic and metastasis suppressor RKIP. In contrast, PDT-induced high levels of NO result in the inhibition of NF-kB, Snail, and YY1 and the induction of RKIP, all of which result in significant anti-tumor cytotoxicity. The direct role of PDT-induced NO effects was corroborated by the use of the NO inhibitor, l-NAME, which reversed the PDT-mediated cytotoxic and cytoprotective effects. In addition, the combination of the NO donor, DETANONOate, and PDT potentiated the PDT-mediated cytotoxic effects. These findings revealed a new mechanism of PDT-induced NO effects and suggested the potential therapeutic application of the combination of NO donors/iNOS inducers and PDT in the treatment of various cancers. In addition, the study suggested that the combination of PDT with subtoxic cytotoxic drugs will result in significant synergy since NO has been shown to be a significant chemo-immunosensitizing agent to apoptosis. PDT-mediated cytotoxic and cytoprotective effects depend also by the induction of NO from tumor. The PDT-induced NO modulates the dysregulated NF-kB/Snail/RKIP loop. The direct role of NO induction by PDT was corroborated by the use of the NO inhibitor, l-NAME. The combination of an NO donor and PDT resulted in a increased cytotoxic effect, in vitro and in vivo. Novel potential therapeutic applications are proposed for the use of PDT combined with NO donors.
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Affiliation(s)
- Valentina Rapozzi
- Department of Medical and Biological Sciences, University of Udine, P.le Kolbe 4, 33100 Udine, Italy.
| | - Emilia Della Pietra
- Department of Medical and Biological Sciences, University of Udine, P.le Kolbe 4, 33100 Udine, Italy.
| | - Benjamin Bonavida
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, CA 90095, USA.
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11
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Liu ZT, Xiong L, Liu ZP, Miao XY, Lin LW, Wen Y. In vivo and in vitro evaluation of the cytotoxic effects of Photosan-loaded hollow silica nanoparticles on liver cancer. NANOSCALE RESEARCH LETTERS 2014; 9:319. [PMID: 25024681 PMCID: PMC4082675 DOI: 10.1186/1556-276x-9-319] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 06/06/2014] [Indexed: 05/04/2023]
Abstract
This study aimed to compare the inhibitory effects of photosensitizers loaded in hollow silica nanoparticles and conventional photosensitizers on HepG2 human hepatoma cell proliferation and determine the underlying mechanisms. Photosensitizers (conventional Photosan-II or nanoscale Photosan-II) were administered to in vitro cultured HepG2 hepatoma cells and treated by photodynamic therapy (PDT) with various levels of light exposure. To assess photosensitizers' effects, cell viability was determined by 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In addition, apoptotic and necrotic cells were measured by flow cytometry and the expression of caspase-3 and caspase-9 evaluated by western blot. Finally, the in vivo effects of nanoscale and conventional photosensitizers on liver cancer were assessed in nude mice. Nanoscale Photosan-II significantly inhibited hepatoma cell viability in a concentration-dependent manner and this effect was more pronounced with high laser doses. Moreover, nanoscale photosensitizers performed better than the conventional ones under the same experimental conditions (p < 0.05). Flow cytometry data demonstrated that laser-induced cell death was markedly increased after treatment with nanoscale Photosan-II in comparison with free Photosan-II (p < 0.05). Activated caspase-3 and caspase-9 levels were significantly higher in cells treated with Photosan-II loaded in silica nanoparticles than free Photosan-II (p < 0.05). Accordingly, treatment with nanoscale photosensitizers resulted in improved outcomes (tumor volume) in a mouse model of liver cancer, in comparison with conventional photosensitizers. Hollow silica nanoparticles containing photosensitizer more efficiently inhibited hepatoma cells than photosensitizer alone, through induction of apoptosis, both in vivo and in vitro.
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Affiliation(s)
- Zhong-Tao Liu
- General Surgery Department, Second Xiangya Hospital, Central South University, Changsha 410011, Hunan, P.R., China
| | - Li Xiong
- General Surgery Department, Second Xiangya Hospital, Central South University, Changsha 410011, Hunan, P.R., China
| | - Zhi-Peng Liu
- General Surgery Department, Second Xiangya Hospital, Central South University, Changsha 410011, Hunan, P.R., China
| | - Xiong-Ying Miao
- General Surgery Department, Second Xiangya Hospital, Central South University, Changsha 410011, Hunan, P.R., China
| | - Liang-Wu Lin
- State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, Hunan, P.R., China
| | - Yu Wen
- General Surgery Department, Second Xiangya Hospital, Central South University, Changsha 410011, Hunan, P.R., China
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12
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Rubio N, Martínez-Junza V, Estruga J, Borrell JI, Mora M, Sagristá ML, Nonell S. Ground- and excited-state interactions of 2,7,12,17-tetraphenylporphycene with model target biomolecules for type-I photodynamic therapy. J PORPHYR PHTHALOCYA 2012. [DOI: 10.1142/s1088424609000103] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Biosubstrate-sensitizer binding is one of the factors that enhances the type-I mechanism over the type-II in the whole photodynamic process. 2,7,12,17-Tetraphenylporphycene (TPPo), a second-generation photosensitizer, is a hydrophobic compound with good photophysical properties for photodynamic therapy applications that has proved its ability for the photoinactivation of different cell lines. Nevertheless, little is known about its mechanism of action. This paper focuses on the study of the interaction/binding of TPPo with different model biomolecules that may favor the type-I mechanism in the overall photodynamic process, including nucleosides, proteins, and phospholipids. Compared with more hydrophilic photosensitizers, it is concluded that TPPo is more likely to undergo type-II (singlet oxygen) than type-I (electron transfer) photodynamic processes in biological environments.
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Affiliation(s)
- Noemí Rubio
- Grup d'Enginyeria Molecular, Institut Químic de Sarrià, Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain
| | - Víctor Martínez-Junza
- Grup d'Enginyeria Molecular, Institut Químic de Sarrià, Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain
| | - Jordi Estruga
- Grup d'Enginyeria Molecular, Institut Químic de Sarrià, Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain
| | - José I. Borrell
- Grup d'Enginyeria Molecular, Institut Químic de Sarrià, Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain
| | - Margarita Mora
- Departament de Bioquímica i Biología Molecular, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal 645, 08028 Barcelona, Spain
| | - M. Lluïsa Sagristá
- Departament de Bioquímica i Biología Molecular, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal 645, 08028 Barcelona, Spain
| | - Santi Nonell
- Grup d'Enginyeria Molecular, Institut Químic de Sarrià, Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain
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13
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RADZI R, OSAKI T, TSUKA T, IMAGAWA T, MINAMI S, OKAMOTO Y. Morphological Study in B16F10 Murine Melanoma Cells after Photodynamic Hyperthermal Therapy with Indocyanine Green (ICG). J Vet Med Sci 2012; 74:465-72. [DOI: 10.1292/jvms.11-0467] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Rozanaliza RADZI
- The United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi 753-8515, Japan
| | - Tomohiro OSAKI
- Department of Veterinary Surgery, School of Veterinary Medicine, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan
| | - Takeshi TSUKA
- Department of Veterinary Diagnostic Imaging, School of Veterinary Medicine, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan
| | - Tomohiro IMAGAWA
- Department of Veterinary Diagnostic Imaging, School of Veterinary Medicine, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan
| | - Saburo MINAMI
- Department of Veterinary Surgery, School of Veterinary Medicine, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan
| | - Yoshiharu OKAMOTO
- Department of Veterinary Neurology and Oncology, School of Veterinary Medicine, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan
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14
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Agostinis P, Berg K, Cengel KA, Foster TH, Girotti AW, Gollnick SO, Hahn SM, Hamblin MR, Juzeniene A, Kessel D, Korbelik M, Moan J, Mroz P, Nowis D, Piette J, Wilson BC, Golab J. Photodynamic therapy of cancer: an update. CA Cancer J Clin 2011; 61:250-81. [PMID: 21617154 PMCID: PMC3209659 DOI: 10.3322/caac.20114] [Citation(s) in RCA: 3216] [Impact Index Per Article: 247.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Photodynamic therapy (PDT) is a clinically approved, minimally invasive therapeutic procedure that can exert a selective cytotoxic activity toward malignant cells. The procedure involves administration of a photosensitizing agent followed by irradiation at a wavelength corresponding to an absorbance band of the sensitizer. In the presence of oxygen, a series of events lead to direct tumor cell death, damage to the microvasculature, and induction of a local inflammatory reaction. Clinical studies revealed that PDT can be curative, particularly in early stage tumors. It can prolong survival in patients with inoperable cancers and significantly improve quality of life. Minimal normal tissue toxicity, negligible systemic effects, greatly reduced long-term morbidity, lack of intrinsic or acquired resistance mechanisms, and excellent cosmetic as well as organ function-sparing effects of this treatment make it a valuable therapeutic option for combination treatments. With a number of recent technological improvements, PDT has the potential to become integrated into the mainstream of cancer treatment.
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Affiliation(s)
- Patrizia Agostinis
- Department of Molecular Cell Biology, Cell Death Research & Therapy Laboratory, Catholic University of Leuven, B-3000 Leuven, Belgium,
| | - Kristian Berg
- Department of Radiation Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, N-0310 Oslo, Norway, ;
| | - Keith A. Cengel
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19004, USA, ;
| | - Thomas H. Foster
- Department of Imaging Sciences, University of Rochester, Rochester, NY 14642, USA,
| | - Albert W. Girotti
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, 53226-3548, USA,
| | - Sandra O. Gollnick
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Elm and Carlton Sts, Buffalo, NY, 14263, USA,
| | - Stephen M. Hahn
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19004, USA, ;
| | - Michael R. Hamblin
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114-2696, USA, ;
- Department of Dermatology, Harvard Medical School, Boston MA 02115
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA 02139, USA
| | - Asta Juzeniene
- Department of Radiation Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, N-0310 Oslo, Norway, ;
| | - David Kessel
- Department of Pharmacology, Wayne State University School of Medicine, Detroit MI 48201, USA,
| | | | - Johan Moan
- Department of Radiation Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, N-0310 Oslo, Norway, ;
- Institute of Physics, University of Oslo, Blindern 0316 Oslo, Norway;
| | - Pawel Mroz
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114-2696, USA, ;
- Department of Dermatology, Harvard Medical School, Boston MA 02115
| | - Dominika Nowis
- Department of Immunology, Centre of Biostructure Research, Medical University of Warsaw, Poland, ;
| | - Jacques Piette
- GIGA-Research, Laboratory of Virology & Immunology, University of Liège, B-4000 Liège Belgium,
| | - Brian C. Wilson
- Ontario Cancer Institute/University of Toronto, Toronto, ON M5G 2M9, Canada,
| | - Jakub Golab
- Department of Immunology, Centre of Biostructure Research, Medical University of Warsaw, Poland, ;
- Institute of Physical Chemistry, Polish Academy of Sciences, Department 3, Warsaw, Poland
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15
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Sibani SA, McCarron PA, Woolfson AD, Donnelly RF. Photosensitiser delivery for photodynamic therapy. Part 2: systemic carrier platforms. Expert Opin Drug Deliv 2009; 5:1241-54. [PMID: 18976134 DOI: 10.1517/17425240802444673] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND The treatment of solid tumours and angiogenic ocular diseases by photodynamic therapy (PDT) requires the injection of a photosensitiser (PS) to destroy target cells through a combination of visible light irradiation and molecular oxygen. There is currently great interest in the development of efficient and specific carrier delivery platforms for systemic PDT. OBJECTIVE This article aims to review recent developments in systemic carrier delivery platforms for PDT, with an emphasis on target specificity. METHODS Recent publications, spanning the last five years, concerning delivery carrier platforms for systemic PDT were reviewed, including PS conjugates, dendrimers, micelles, liposomes and nanoparticles. RESULTS/CONCLUSION PS conjugates and supramolecular delivery platforms can improve PDT selectivity by exploiting cellular and physiological specificities of the targeted tissue. Overexpression of receptors in cancer and angiogenic endothelial cells allows their targeting by affinity-based moieties for the selective uptake of PS conjugates and encapsulating delivery carriers, while the abnormal tumour neovascularisation induces a specific accumulation of heavy weighted PS carriers by enhanced permeability and retention (EPR) effect. In addition, polymeric prodrug delivery platforms triggered by the acidic nature of the tumour environment or the expression of proteases can be designed. Promising results obtained with recent systemic carrier platforms will, in due course, be translated into the clinic for highly efficient and selective PDT protocols.
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Affiliation(s)
- Stéphane A Sibani
- Queens University Belfast, Medical Biology Centre, School of Pharmacy, 97 Lisburn Road, Belfast BT9 7BL, UK
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16
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Solban N, Ortel B, Pogue B, Hasan T. Targeted optical imaging and photodynamic therapy. ERNST SCHERING RESEARCH FOUNDATION WORKSHOP 2005:229-58. [PMID: 15524219 DOI: 10.1007/3-540-26809-x_12] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Affiliation(s)
- N Solban
- Wellman Laboratories of Photomedicine, Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
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17
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Soncin M, Fabris C, Busetti A, Dei D, Nistri D, Roncucci G, Jori G. Approaches to selectivity in the Zn(II)-phthalocyanine-photosensitized inactivation of wild-type and antibiotic-resistant Staphylococcus aureus. Photochem Photobiol Sci 2002; 1:815-9. [PMID: 12656484 DOI: 10.1039/b206554a] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A number of Zn(II)- phthalocyanines bearing peripheral substituents of cationic nature due to the presence of quaternarized anilinium or ammonium groups were shown to be efficient photoantimicrobial agents: a 4-5 log decrease in the survival of both wild-type or methicillin-resistant Staphylococcus aureus was obtained upon short irradiation times in the presence of phthalocyanine concentrations as low as 0.1 microM. A careful selection of the experimental protocol, and in particular the use of short (5 min) incubation times and mild irradiation parameters, allowed one to achieve a high selectivity of S. aureus photoinactivation as compared with important constituents of potential host tissues, such as human fibroblasts and keratinocytes. The efficiency and selectivity of the photoprocess were not affected by the presence of 5% human serum.
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Affiliation(s)
- Marina Soncin
- Molteni Farmaceutici S.S 67 Loc. Granatieri-50018 Scandicci, Firenze, Italy
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18
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Ward T, Mooney D, Flynn G, McHale AP. Electric field-enhanced activation of hematoporphyrin derivative: effects on a human tumour cell line. Cancer Lett 1997; 113:145-51. [PMID: 9065814 DOI: 10.1016/s0304-3835(96)04592-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In a recent report we described the effects of combined electroactivation and photoactivation of hematoporphyrin derivative (HPD) on human erythrocytes and established that activation-induced cell lysis was more pronounced when both modes of activation were sequentially applied to the system. Here we demonstrate that electric field-induced activation of HPD-treated HeLa cells results in cell death. This effect is shown to be dependant on both electric field strength and on HPD concentration. In addition, we demonstrate that exposure of HPD-treated cells to short and intense electric pulses prior to photoactivation, results in increased cell mortality. The results confirm our earlier suggestion that HPD may be activated in the presence of an applied electric field. The results further suggest that activation of photosensitizers using combined exposure to electric fields and light may play an important role in increasing the efficiency of photodynamic therapy (PDT) in the treatment of cancer.
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Affiliation(s)
- T Ward
- School of Applied Biological and Chemical Sciences, University of Ulster, Coleraine, UK
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19
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Polo L, Bianco G, Reddi E, Jori G. The effect of different liposomal formulations on the interaction of Zn(II)-phthalocyanine with isolated low and high density lipoproteins. Int J Biochem Cell Biol 1995; 27:1249-55. [PMID: 8581821 DOI: 10.1016/1357-2725(95)00107-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- L Polo
- Department of Biology, University of Padova, Italy
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20
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Hoebeke M. The importance of liposomes as models and tools in the understanding of photosensitization mechanisms. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1995; 28:189-96. [PMID: 7623183 DOI: 10.1016/1011-1344(95)07132-l] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The various applications of liposomes in understanding photosensitization are described in this paper, with particular emphasis on the various kinds of information that these models allow to obtain in phototherapy. Liposomes are simple vesicles in which an aqueous phase is enclosed by a phospholipidic membrane. They are suitable models mimicking specific situations occurring in vivo and they allow study of the influence of physicochemical, photobiological and biochemical factors on the uptake of photosensitizers by tissues, their mechanisms of action and the subsequent photoinduced tumor necrosis. Moreover, solubilization of the sensitizer into the bilayer seems to improve its tumoral selectivity and its photodynamic efficiency.
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Affiliation(s)
- M Hoebeke
- Laboratory of Experimental Physics, University of Liège, Belgium
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21
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Rensen PC, Love WG, Taylor PW. In vitro interaction of zinc(II)-phthalocyanine-containing liposomes and plasma lipoproteins. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1994; 26:29-35. [PMID: 7799138 DOI: 10.1016/1011-1344(94)85033-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have studied the interaction of small unilamellar liposomes containing zinc(II)-phthalocyanine (Zn-Pc) with human plasma lipoproteins. High-, low- and very low-density lipoproteins (HDL, LDL and VLDL), were purified from plasma and combined in amounts reflecting their natural abundance in plasma. After short periods of incubation at 37 degrees C, the bulk of Zn-Pc was incorporated into HDL and LDL; very little 14C-labelled palmitoyl oleoyl phosphocholine, the most abundant phospholipid in the formulation, was associated with lipoproteins. When liposomes were incubated in pooled plasma, 73%-85% of Zn-Pc and 27%-34% of radiolabelled phospholipid were recovered with HDL and LDL, indicating a possible role for plasma lipid transfer proteins in the incorporation of phospholipid into lipoproteins. Some Zn-Pc was also found in association with VLDL. The buoyant density of Zn-Pc liposomes increased in a dose-dependent fashion when the particles were incubated with plasma, and it is suggested that this was due, at least in part, to opsonization of liposomes by plasma proteins.
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Affiliation(s)
- P C Rensen
- Exploratory Liposome Technology, CIBA-Geigy Pharmaceuticals, Horsham, West Sussex, UK
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22
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Flynn G, Hackett TJ, McHale L, McHale AP. Magnetically responsive photosensitizing reagents for possible use in photoradiation therapy. Cancer Lett 1994; 78:109-14. [PMID: 8180952 DOI: 10.1016/0304-3835(94)90038-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The ability of a magnetically responsive material to function as a carrier for photosensitizing agents for use in photoradiation therapy (PRT) has been examined in vitro. The photosensitizer has been attached to the magnetically responsive matrix (Dynabeads) by non-specific adsorption, Intralipid-mediated adsorption and poly-L-lysine mediated adsorption. In these studies, it has been demonstrated that conditions of attachment of photosensitizer to the matrix may be adapted in order to facilitate a diffuse or highly localized photo-toxic effect on target cells in vitro. The authors believe that this system may represent a novel approach to targeting photosensitizing agents to specific areas, thereby circumventing some of the problems associated with conventional photoradiation therapy (PRT), particularly in hollow organs.
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Affiliation(s)
- G Flynn
- Department of Biological and Biomedical Sciences, University of Ulster, Coleraine, Co. Londonderry, Northern Ireland, UK
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23
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Korbelik M, Krosl G, Adomat H, Skov KA. The effect of differentiation on photosensitizer uptake by HL60 cells. Photochem Photobiol 1993; 58:670-5. [PMID: 8284322 DOI: 10.1111/j.1751-1097.1993.tb04950.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The capability of human promyelocytic leukemia cells HL60 to be induced to differentiate to various stages along the monocytic or myelocytic pathway was exploited for investigation of the uptake of selected photosensitizers by diverse types of cells of the same origin. The results showed that there was no substantial difference in photofrin uptake between noninduced HL60 cells, immature monocytes, immature neutrophils and cells differentiated along the eosinophilic pathway. In contrast, HL60 cells differentiated into macrophages (HL60 phi) exhibited markedly increased photofrin uptake, which was further enhanced by their pretreatment with bacterial lipopolysaccharide. Similar results were obtained with other photosensitizers tested: di- and tetrasulfonated aluminum phthalocyanines (A1PcS2 and A1PcS4), tetrasulfonated zinc phthalocyanine (ZnPcS4), tetraphenylporphine tetrasulfonate (TPPS4) and benzoporphyrin derivative monoacid (BPD). Despite marked differences in the state of self-aggregation and other chemical properties of these compounds, the degree of their preferential uptake by HL60 phi cells showed very little variation. In a typical experiment, the uptake of these photosensitizers by HL60 phi cells was four to five times higher than the uptake by noninduced HL60 cells. In addition to the fluorometric assay employed in most of the experiments, cellular concentration of A1PcS4 was determined by measurement of elementary aluminum using atomic absorption spectroscopy.
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Affiliation(s)
- M Korbelik
- BC Cancer Research Centre, Vancouver, Canada
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24
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Kongshaug M, Moan J, Cheng LS, Garbo GM, Kolboe S, Morgan AR, Rimington C. Binding of drugs to human plasma proteins, exemplified by Sn(IV)-etiopurpurin dichloride delivered in cremophor and DMSO. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1993; 25:739-60. [PMID: 8349016 DOI: 10.1016/0020-711x(93)90362-i] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
1. The mode-delivery-effect upon the binding of Sn(IV)-etiopurpurin dichloride (SnET2) in human plasma has been studied by ultracentrifugation, combined with absorption and fluorescence spectroscopy. SnET2 was delivered to plasma either in Cremophore EL (CRM) or in dimethyl sulfoxide (DMSO). To facilitate interpretation, optical, conductivity and aggregation properties of SnET2 were obtained for various solutions. 2. The second order rate constant for the aggregation of SnET2 monomers seemed to be remarkably small, of the order of 10(3) M-1 min-1. 3. SnET2 was bound as monomeric entities. Such entities had environmental-sensitive fluorescent properties dependent on the type of protein or solvent (DMSO, CRM, H2O) with which they interacted. 4. SnET2 showed saturable binding with high density subfraction(s) of high density lipoproteins and with one or more high density proteins. Complete or substantial saturation was achieved at the SnET2 level of 3.5 micrograms/ml. Such binding might be mediated by apolipoprotein D and alpha 1-acid glycoprotein. 5. There was little effect of SnET2 concentrations (3.5-35 micrograms SnET2/ml) upon the plasma binding of SnET2, irrespective of the mode of delivery. 6. The percentages of SnET2 bound to low density lipoproteins (LDL), high density lipoproteins (HDL), and high density proteins (HDP) were 10, 70 and 20%, respectively, for delivery in DMSO. The value for LDL also includes binding with very low density lipoproteins (VLDL). For delivery in CRM the corresponding values were 20, 50 and 30%. Apparently, CRM interacted with HDL entities and reduced their affinity for SnET2. 7. The distribution pattern of SnET2 among lipoproteins reflects interactions with apoproteins and/or with surface phospholipids rather than with core lipid constituents of lipoproteins. 8. Conductivity measurements showed that SnET2 was partly an ionic entity in water. 9. The plasma binding of SnET2 is compared with the corresponding binding of other drugs, both tetrapyrroles and nontetrapyrroles.
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Affiliation(s)
- M Kongshaug
- Department of Biophysics, Norwegian Radium Hospital, Oslo
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