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Silva RC, Buzzá HH, Ducas ESA, Oliveira KT, Bagnato VS, Souza GRL, Almeida LM, Gonçalves PJ. Synergic vascular photodynamic activity by methylene blue-curcumin supramolecular assembly. Spectrochim Acta A Mol Biomol Spectrosc 2023; 303:123281. [PMID: 37625276 DOI: 10.1016/j.saa.2023.123281] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 08/14/2023] [Accepted: 08/18/2023] [Indexed: 08/27/2023]
Abstract
A supramolecular assembly was obtained by combining methylene blue (MB) with a natural plant extract, curcumin (Curc), in a stoichiometric ratio of 1:4 in aqueous solution (90% PBS + 10% ethanol) at room temperature. The MB-Curc supramolecular assembly was evidenced by absorption and fluorescence spectroscopies, and the stoichiometry and bonding constant were obtained using Cieleńs model. Its stability and photostability were evaluated by chromatographic analysis and UV-Vis absorption. The MB-Curc avoids the aggregation of both isolated compounds and efficiently produces singlet oxygen (ΦΔ= 0.52 ± 0.03). Its potential for photodynamic antiangiogenic treatments was evaluated through the vascular effect observed in chicken chorioallantoic membrane (CAM) assay. The results showed intense damage in CAM vascular network by MB-Curc after irradiation, which is higher than the effect of isolated compounds, indicating a synergistic vascular effect. This combination can be essential to prevent cancer revascularization after photodynamic application and improve the efficacy of this approach. The characteristics exhibited by MB-Curc make it a potential candidate for use in cancer treatments through photodynamic antiangiogenic therapy.
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Affiliation(s)
- Rodrigo C Silva
- Instituto de Química, Universidade Federal de Goiás (UFG), Goiânia, GO, Brazil; Departamento de Química, Universidade Federal de São Carlos (UFSCar), São Carlos, SP, Brazil.
| | - Hilde H Buzzá
- Instituto de Física de São Carlos, Universidade de São Paulo (IFSC, USP), São Carlos, SP, Brazil; Instituto de Física, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Eli S A Ducas
- Instituto de Química, Universidade Federal de Goiás (UFG), Goiânia, GO, Brazil
| | - Kleber T Oliveira
- Departamento de Química, Universidade Federal de São Carlos (UFSCar), São Carlos, SP, Brazil
| | - Vanderlei S Bagnato
- Instituto de Física de São Carlos, Universidade de São Paulo (IFSC, USP), São Carlos, SP, Brazil; Hagler Fellow, Texas A&M University, College Station, United States
| | - Guilherme R L Souza
- Instituto de Ciências Biológicas, Universidade Federal de Goiás (UFG), Goiânia, GO, Brazil
| | - Luciane M Almeida
- Universidade Estadual de Goiás (UEG), Campus Anápolis de Ciências Exatas e Tecnológicas, Anápolis, GO, Brazil
| | - Pablo J Gonçalves
- Instituto de Química, Universidade Federal de Goiás (UFG), Goiânia, GO, Brazil; Instituto de Física, Universidade Federal de Goiás (UFG), Goiânia, GO, Brazil.
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Kwon N, Jasinevicius GO, Kassab G, Ding L, Bu J, Martinelli LP, Ferreira VG, Dhaliwal A, Chan HHL, Mo Y, Bagnato VS, Kurachi C, Chen J, Zheng G, Buzzá HH. Nanostructure-Driven Indocyanine Green Dimerization Generates Ultra-Stable Phototheranostics Nanoparticles. Angew Chem Int Ed Engl 2023:e202305564. [PMID: 37162307 DOI: 10.1002/anie.202305564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 05/05/2023] [Accepted: 05/10/2023] [Indexed: 05/11/2023]
Abstract
Indocyanine green (ICG) is the only NIR-dye approved for clinical use. Despite its versatility in photonic applications and potential for photothermal therapy, its photobleaching hinders its application. Here we discovered a nanostructure of dimeric ICG (Nano-dICG) generated by using ICG to stabilize nanoemulsion, after which ICG enabled complete dimerization on the nanoemulsion shell, followed by J-aggregation of ICG-dimer, resulting in a narrow, red-shifted (780nm → 894nm) and intense (~2-fold) absorbance. Compared to ICG, Nano-dICG demonstrated superior photothermal conversion (2-fold higher), significantly reduced photodegradation (-9.6% vs. -46.3%), and undiminished photothermal effect (7 vs. 2 cycles) under repeated irradiations, in addition to excellent colloidal and structural stabilities. Following intravenous injection, Nano-dICG enabled real-time tracking of its delivery to mouse tumor within 24h by photoacoustic imaging at a NIR wavelength (890nm) distinct from the endogenous signal to guide effective photothermal therapy. The unprecedented finding of nanostructure-driven ICG dimerization leads to ultra-stable phototheranostic platform.
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Affiliation(s)
- Nahyun Kwon
- University Health Network, Princess Margaret Cancer Centre, CANADA
| | - Gabriel O Jasinevicius
- University of Sao Paulo: Universidade de Sao Paulo, Sao Carlos Institute of Physics, BRAZIL
| | - Giulia Kassab
- University Health Network, Princess Margaret Cancer Centre, CANADA
| | - Lili Ding
- University Health Network, Princess Margaret Cancer Centre, CANADA
| | - Jiachuan Bu
- University Health Network, Princess Margaret Cancer Centre, CANADA
| | - Letícia P Martinelli
- University of Sao Paulo: Universidade de Sao Paulo, Sao Carlos Institute of Physics, BRAZIL
| | | | | | - Harley H L Chan
- University Health Network, Princess Margaret Cancer Centre, CANADA
| | - Yulin Mo
- University of Toronto, Institute of Medical Sciences, CANADA
| | - Vanderlei S Bagnato
- University of Sao Paulo: Universidade de Sao Paulo, Sao Carlos Institute of Physics, BRAZIL
| | - Cristina Kurachi
- University of Sao Paulo: Universidade de Sao Paulo, Sao Carlos Institute of Physics, BRAZIL
| | - Juan Chen
- University Health Network, Princess Margaret Cancer Centre, CANADA
| | - Gang Zheng
- University of Toronto, Princess Margaret Cancer Centre, 101 College St, PMCRT 5-354, Canada, M5G1L7, Toronto, CANADA
| | - Hilde H Buzzá
- Pontifical Catholic University of Chile: Pontificia Universidad Catolica de Chile, Institute of Physics, CHILE
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Tiburcio MA, Rocha AR, Romano RA, Inada NM, Bagnato VS, Carlos RM, Buzzá HH. In vitro evaluation of the cis-[Ru(phen) 2(pPDIp)] 2+⁎⁎ complex for antimicrobial photodynamic therapy against Sporothrix brasiliensis and Candida albicans. J Photochem Photobiol B 2022; 229:112414. [PMID: 35276578 DOI: 10.1016/j.jphotobiol.2022.112414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 02/10/2022] [Accepted: 02/21/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Photodynamic therapy (PDT) activates a photosensitizer by visible light to generate cytotoxic oxygen species that lead to cell death. With proper illumination, PDT is often used in applications on superficial and sub-surface lesions. Sporotrichosis infection occurs by Sporothrix fungi which causes a skin wound, worsened by Candida albicans infections. This study investigated the photosensitizing efficiency of the Ru(phen)2(pPDIp)(PF6)2 complex, RupPDIp, against S. brasiliensis and C. albicans. MATERIAL AND METHODS RupPDIp efficiency against these fungi was tested using 450 nm (blue light and 36 J/cm2) and 525 nm (green light, 25.2 J/cm2) at 0.05-20 μM concentrations. To ensure PDT effectiveness, control groups were tested in the absence and in the presence of RupPDIp under light irradiation and in the dark. RESULTS RupPDIp eliminated both fungi at ≤5.0 μM. Green light showed the best results, eliminating S. brasiliensis and C. albicans colonies at RupPDIp 0.5 μM and 0.05 μM, respectively. CONCLUSION RupPDIp is a promising photosensitizer in aPDT, eliminating 106 CFU/mL of both fungi at 450 nm and 525 nm, with lower light doses and concentrations when treated with the green light compared to the blue light.
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Affiliation(s)
- M A Tiburcio
- Chemistry Department, Federal University of São Carlos, Brazil.
| | - A R Rocha
- São Carlos Institute of Physics, University of Sao Paulo, Brazil; PPG Biotec, Federal University of São Carlos, Brazil
| | - R A Romano
- São Carlos Institute of Physics, University of Sao Paulo, Brazil
| | - N M Inada
- São Carlos Institute of Physics, University of Sao Paulo, Brazil
| | - V S Bagnato
- São Carlos Institute of Physics, University of Sao Paulo, Brazil; Hagler Fellow, Texas A&M University, College Station, TX, USA
| | - R M Carlos
- Chemistry Department, Federal University of São Carlos, Brazil
| | - H H Buzzá
- São Carlos Institute of Physics, University of Sao Paulo, Brazil; Institute of Physics, Pontificia Universidad Católica de Chile, Santiago, Chile.
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Lagos KJ, Buzzá HH, Bagnato VS, Romero MP. Carbon-Based Materials in Photodynamic and Photothermal Therapies Applied to Tumor Destruction. Int J Mol Sci 2021; 23:22. [PMID: 35008458 PMCID: PMC8744821 DOI: 10.3390/ijms23010022] [Citation(s) in RCA: 122] [Impact Index Per Article: 40.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 11/25/2021] [Accepted: 11/27/2021] [Indexed: 12/16/2022] Open
Abstract
Within phototherapy, a grand challenge in clinical cancer treatments is to develop a simple, cost-effective, and biocompatible approach to treat this disease using ultra-low doses of light. Carbon-based materials (CBM), such as graphene oxide (GO), reduced GO (r-GO), graphene quantum dots (GQDs), and carbon dots (C-DOTs), are rapidly emerging as a new class of therapeutic materials against cancer. This review summarizes the progress made in recent years regarding the applications of CBM in photodynamic (PDT) and photothermal (PTT) therapies for tumor destruction. The current understanding of the performance of modified CBM, hybrids and composites, is also addressed. This approach seeks to achieve an enhanced antitumor action by improving and modulating the properties of CBM to treat various types of cancer. Metal oxides, organic molecules, biopolymers, therapeutic drugs, among others, have been combined with CBM to treat cancer by PDT, PTT, or synergistic therapies.
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Affiliation(s)
- Karina J. Lagos
- Department of Materials, Escuela Politécnica Nacional (EPN), Quito 170525, Ecuador;
| | - Hilde H. Buzzá
- Institute of Physics, Pontificia Universidad Católica de Chile, Santiago 7820436, Chile;
- São Carlos Institute of Physics, University of São Paulo (USP), São Carlos 13566-590, Brazil;
| | - Vanderlei S. Bagnato
- São Carlos Institute of Physics, University of São Paulo (USP), São Carlos 13566-590, Brazil;
| | - María Paulina Romero
- Department of Materials, Escuela Politécnica Nacional (EPN), Quito 170525, Ecuador;
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5
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Charron DM, Yousefalizadeh G, Buzzá HH, Rajora MA, Chen J, Stamplecoskie KG, Zheng G. Correction to "Photophysics of J-Aggregating Porphyrin-Lipid Photosensitizers in Liposomes: Impact of Lipid Saturation". Langmuir 2020; 36:9985. [PMID: 32799516 DOI: 10.1021/acs.langmuir.0c02199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
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Charron DM, Yousefalizadeh G, Buzzá HH, Rajora MA, Chen J, Stamplecoskie KG, Zheng G. Photophysics of J-Aggregating Porphyrin-Lipid Photosensitizers in Liposomes: Impact of Lipid Saturation. Langmuir 2020; 36:5385-5393. [PMID: 32338515 DOI: 10.1021/acs.langmuir.0c00843] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Porphyrin aggregates have attractive photophysical properties for phototherapy and optical imaging, including quenched photosensitization, efficient photothermal conversion, and unique absorption spectra. Although hydrophobic porphyrin photosensitizers have long been encapsulated into liposomes for drug delivery, little is known about the membrane properties of liposomes with large amphiphilic porphyrin compositions. In this paper, a porphyrin-lipid conjugate was incorporated into liposomes formed of saturated or unsaturated lipids to study the membrane composition-dependent formation of highly ordered porphyrin J-aggregates and disordered aggregates. Porphyrin-lipid readily phase-separates in saturated membranes, forming J-aggregates that are destabilized during the ripple phase below the main thermal transition. Porphyrin-lipid J-aggregates are photostable with a photothermal efficiency of 54 ± 6%, comparable to gold. Even at high porphyrin-lipid compositions, porphyrin J-aggregates coexist with a minority population of disordered aggregates, which are photodynamically active despite being fluorescently quenched. For photothermal applications, liposome formulations that encourage porphyrin-lipid phase separation should be explored for maximum J-aggregation.
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Affiliation(s)
- Danielle M Charron
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 1L7, Canada
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | | | - Hilde H Buzzá
- São Carlos Institute of Physics, University of São Paulo (USP), CEP 13563-120 São Carlos, Brazil
| | - Maneesha A Rajora
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 1L7, Canada
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Juan Chen
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 1L7, Canada
| | | | - Gang Zheng
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 1L7, Canada
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7, Canada
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Buzzá HH, Zangirolami AC, Kurachi C, Bagnato VS. Acceleration of newborn rats' development with the use of photobiomodulation and the near possibility of application in human premature babies. J Biophotonics 2019; 12:e201800461. [PMID: 30972966 DOI: 10.1002/jbio.201800461] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 04/05/2019] [Accepted: 04/08/2019] [Indexed: 06/09/2023]
Abstract
Photobiomodulation was explored to find evidence of stimulation during the development of newborn rats. A light chamber device was used, and rat pups were divided into groups after birth. Investigation of the process' security was performed before the full experiment. Following a protocol of alternating illumination and mother's presence during the first 13 days, we observed that, in the group that received photobiomodulation, the pups opened their eyes faster, indicating earlier achievement of maturity. The rate of weight gain also indicates faster metabolic activity in the group that was photostimulated. This study is the first step toward the use of photobiomodulation for premature newborn human babies.
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Affiliation(s)
- Hilde H Buzzá
- Department of Physics and Materials Science, São Carlos Institute of Physics, University of São Paulo (USP), São Paulo, Brazil
| | - Amanda C Zangirolami
- Department of Physics and Materials Science, São Carlos Institute of Physics, University of São Paulo (USP), São Paulo, Brazil
| | - Cristina Kurachi
- Department of Physics and Materials Science, São Carlos Institute of Physics, University of São Paulo (USP), São Paulo, Brazil
| | - Vanderlei S Bagnato
- Department of Physics and Materials Science, São Carlos Institute of Physics, University of São Paulo (USP), São Paulo, Brazil
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8
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Ferreira LM, Alonso JD, Kiill CP, Ferreira NN, Buzzá HH, Martins de Godoi DR, de Britto D, Assis OBG, Seraphim TV, Borges JC, Gremião MPD. Exploiting supramolecular interactions to produce bevacizumab-loaded nanoparticles for potential mucosal delivery. Eur Polym J 2018. [DOI: 10.1016/j.eurpolymj.2018.04.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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9
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Buzzá HH, Zangirolami AC, Kurachi C, Bagnato VS. Photostimulation effects on chicken egg development: Perspectives on human newborn treatment. J Biophotonics 2018; 11:e201700046. [PMID: 28700130 DOI: 10.1002/jbio.201700046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 06/01/2017] [Accepted: 06/03/2017] [Indexed: 06/07/2023]
Abstract
It is well known that, under exposure to bright light, eggs tend to hatch earlier than control, without any damage to the birds. This report aims to systematically show the effect and establishes a proposal for a possible application to accelerate chicken egg formation, which could be extrapolated or adapted as a great advance in premature human newborns. Comparing several protocols, the experiments show that lower doses of light slowly delivered for 24 h promote higher efficiency in embryo development, increasing on average 25% of its size and more than 70% in weight when compared to the control. This weight difference shows promising results compared to rates of up to 17% found in the literature. These results can be a first step to reduce the stay of premature human infants in hospitals because light, when applied in very low doses, can accelerate the natural biological processes without risks.
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Affiliation(s)
- Hilde H Buzzá
- São Carlos Institute of Physics, University of São Paulo (USP), São Carlos, Brazil
| | - Amanda C Zangirolami
- São Carlos Institute of Physics, University of São Paulo (USP), São Carlos, Brazil
| | - Cristina Kurachi
- São Carlos Institute of Physics, University of São Paulo (USP), São Carlos, Brazil
| | - Vanderlei S Bagnato
- São Carlos Institute of Physics, University of São Paulo (USP), São Carlos, Brazil
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10
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Blanco KC, Inada NM, Silva AP, Stringasci MD, Buzzá HH, Ramirez DP, Sálvio AG, Moriyama LT, Kurachi C, Bagnato VS. A Multicenter Clinical Study of Expected and Unexpected Side Reactions During and After Skin Cancer Treatment by Photodynamic Therapy. Skinmed 2017; 15:113-118. [PMID: 28528604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Photodynamic therapy (PDT) has been widely used for oncologic indications, especially nonmelanoma skin cancer such as superficial and nodular basal cell carcinoma (BCC). We present a multicenter clinical study conducted between 2012 and 2014 analyzing the adverse reactions during and after PDT with a standardized protocol in 866 lesions. A total of 728 patients with positive clinical and histopathological diagnosis for BCC with up to 2 cm diameter were treated. The procedure consisted of curettage and topical application of cream containing 20% methyl 5-aminolevulinate. The illumination (630 nm and 150 J/cm2) was performed 3 hours after the cream application. The expected and unexpected effects observed were pain, healing, and inflammatory reactions. The pain intensity was correlated with the anatomical localization of the lesion. The patients reported a higher intensity of pain in lesions located on the head and neck rather than on the trunk and limbs. The number of sessions also influenced the pain response. A total of 83% of patients showed perfect healing and the other 17% presented abnormal healing. PDT plays an important role in BCC because of its low cost, ease of use, and low rate of side effects.
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Affiliation(s)
- Kate C Blanco
- University of São Paulo, São Carlos Institute of Physics, São Carlos, São Paulo, Brazil;
| | - Natalia M Inada
- University of São Paulo, São Carlos Institute of Physics, São Carlos, São Paulo, Brazil
| | - Ana P Silva
- University of São Paulo, São Carlos Institute of Physics, São Carlos, São Paulo, Brazil
| | - Mirian D Stringasci
- University of São Paulo, São Carlos Institute of Physics, São Carlos, São Paulo, Brazil
| | - Hilde H Buzzá
- University of São Paulo, São Carlos Institute of Physics, São Carlos, São Paulo, Brazil
| | - Dora P Ramirez
- Federal University of São Carlos, PPGBiotec, São Carlos, São Paulo, Brazil
| | - Ana G Sálvio
- Hospital Amaral Carvalho, Jaú, São Paulo, Brazil
| | - Lilian T Moriyama
- University of São Paulo, São Carlos Institute of Physics, São Carlos, São Paulo, Brazil
| | - Cristina Kurachi
- University of São Paulo, São Carlos Institute of Physics, São Carlos, São Paulo, Brazil
| | - Vanderlei S Bagnato
- University of São Paulo, São Carlos Institute of Physics, São Carlos, São Paulo, Brazil
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11
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Blanco KC, Inada NM, Silva APD, Russignoli P, Ramirez DP, Buzzá HH, Stringasci MD, Moriyama LT, Grecco C, Kurachi C, Bagnato VS. PDT Brazil - A New Approach for Basal Cell Carcinoma Treatment. Photodiagnosis Photodyn Ther 2015. [DOI: 10.1016/j.pdpdt.2015.07.188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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12
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Buzzá HH, Silva APD, Vollet Filho JD, Ramirez DP, Trujillo JR, Inada NM, Moriyama LT, Kurachi C, Bagnato VS. Photodynamic therapy: Progress toward a scientific and clinical network in Latin America. Photodiagnosis Photodyn Ther 2015; 13:261-266. [PMID: 26296697 DOI: 10.1016/j.pdpdt.2015.08.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 08/12/2015] [Accepted: 08/13/2015] [Indexed: 10/23/2022]
Abstract
Cancer is one of the major challenges for Latin America health services, since the skin cancer is the most frequent lesion. This manuscript addresses an initiative for the treatment of basal cell carcinomas (BCC) by photodynamic therapy (PDT) based on a government-funded national program in Brazil. The program provides clinical training and facilitates access to drugs/equipment and significantly reduces PDT costs. It also lays foundations for the establishment of a Latin American research network to improve prevention, early detection and treatment of diseases. Centers have been established by direct contact (conferences, visits to healthcare facilities and official departments). A local training was divided into complementary theoretical and practical parts. This is an ongoing project that has involved 10 countries: Brazil, Bolivia Chile, Ecuador, El Salvador, Colombia, Cuba, Mexico, Peru and Venezuela, The initial results are encouraging and have provided assessment of Latin America patients relating, for example, the most common skin phototypes with incidence of BCC in such countries. The network is expected to produce relevant scientific information for PDT introduction in many countries. The experience acquired by local teams shall enable them to innovate PDT protocols and increase the number of skilled contributors/researchers to broaden knowledge on the ever-crescent PDT field in Latin America. The establishment of a collaboration network and introduction of other projects and experience exchange shall become an easier process with time. This PDT clinical research network is a start for the strengthening of Science in South Hemisphere countries.
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Affiliation(s)
- Hilde H Buzzá
- São Carlos Institute of Physics, University of São Paulo (USP), P.O. Box 369, 13560-970 São Carlos, São Paulo, Brazil.
| | - Ana Paula da Silva
- São Carlos Institute of Physics, University of São Paulo (USP), P.O. Box 369, 13560-970 São Carlos, São Paulo, Brazil
| | - José Dirceu Vollet Filho
- São Carlos Institute of Physics, University of São Paulo (USP), P.O. Box 369, 13560-970 São Carlos, São Paulo, Brazil
| | - Dora Patricia Ramirez
- São Carlos Institute of Physics, University of São Paulo (USP), P.O. Box 369, 13560-970 São Carlos, São Paulo, Brazil
| | | | - Natalia M Inada
- São Carlos Institute of Physics, University of São Paulo (USP), P.O. Box 369, 13560-970 São Carlos, São Paulo, Brazil
| | - Lilian T Moriyama
- São Carlos Institute of Physics, University of São Paulo (USP), P.O. Box 369, 13560-970 São Carlos, São Paulo, Brazil
| | - Cristina Kurachi
- São Carlos Institute of Physics, University of São Paulo (USP), P.O. Box 369, 13560-970 São Carlos, São Paulo, Brazil
| | - Vanderlei S Bagnato
- São Carlos Institute of Physics, University of São Paulo (USP), P.O. Box 369, 13560-970 São Carlos, São Paulo, Brazil
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13
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Garcia W, Figueira ACM, de Oliveira Neto M, de Guzzi CA, Buzzá HH, Portugal RV, Calgaro MR, Polikarpov I. Probing conformational changes in orphan nuclear receptor: the NGFI-B intermediate is a partially unfolded dimer. Biophys Chem 2008; 137:81-7. [PMID: 18676081 DOI: 10.1016/j.bpc.2008.07.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2008] [Revised: 07/12/2008] [Accepted: 07/14/2008] [Indexed: 10/21/2022]
Abstract
Human nerve growth factor-induced B (NGFI-B) is a member of the NR4A subfamily of orphan nuclear receptors (NRs). Lacking identified ligands, orphan NRs show particular co-regulator proteins binding properties, different from other NRs, and they might have a non-classical quaternary organization. A body of evidence suggests that NRs recognition of and binding to ligands, DNA, homo- and heterodimerization partners and co-regulator proteins involve significant conformational changes of the NR ligand-binding domains (LBDs). To shed light on largely unknown biophysical properties of NGFI-B, here we studied structural organization and unfolding properties of NGFI-B ligand (like)-binding domain induced by chemical perturbation. Our results show that NGFI-B LBD undergoes a two-state guanidine hydrochloride (GndHCl) induced denaturation, as judged by changes in the alpha-helical content of the protein monitored by circular dichroism spectroscopy (CD). In contrast, changes in the tertiary structure of NGFI-B LBD, reported by intrinsic fluorescence, reveal a clear intermediate state. Additionally, SAXS results demonstrate that the intermediate observed by intrinsic fluorescence is a partially folded homodimeric structure, which further unfolds without dissociation at higher GndHCl concentrations. This partially unfolded dimeric assembly of NGFI-B LBD might resemble an intermediate that this domain access momentarily in the native state upon interactions with functional partners.
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Affiliation(s)
- Wanius Garcia
- Instituto de Física de São Carlos, Universidade de São Paulo, Av. Trabalhador Saocarlense 400, São Carlos, SP, 13560-970, Brazil
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