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Gomes PS, Carneiro MPD, Machado PDA, de Andrade-Neto VV, da Fonseca-Martins AM, Goundry A, Pereira da Silva JVM, Gomes DCO, Lima APCDA, Ennes-Vidal V, Sodero ACR, De-Simone SG, de Matos Guedes HL. Subtilisin of Leishmania amazonensis as Potential Druggable Target: Subcellular Localization, In Vitro Leishmanicidal Activity and Molecular Docking of PF-429242, a Subtilisin Inhibitor. Curr Issues Mol Biol 2022; 44:2089-2106. [PMID: 35678670 PMCID: PMC9164065 DOI: 10.3390/cimb44050141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 02/08/2022] [Accepted: 02/09/2022] [Indexed: 12/14/2022] Open
Abstract
Subtilisin proteases, found in all organisms, are enzymes important in the post-translational steps of protein processing. In Leishmania major and L. donovani, this enzyme has been described as essential to their survival; however, few compounds that target subtilisin have been investigated for their potential as an antileishmanial drug. In this study, we first show, by electron microscopy and flow cytometry, that subtilisin has broad localization throughout the cytoplasm and membrane of the parasite in the promastigote form with foci in the flagellar pocket. Through in silico analysis, the similarity between subtilisin of different Leishmania species and that of humans were determined, and based on molecular docking, we evaluated the interaction capacity of a serine protease inhibitor against both life cycle forms of Leishmania. The selected inhibitor, known as PF-429242, has already been used against the dengue virus, arenaviruses, and the hepatitis C virus. Moreover, it proved to have antilipogenic activity in a mouse model and caused hypolipidemia in human cells in vitro. Here, PF-429242 significantly inhibited the growth of L. amazonensis promastigotes of four different strains (IC50 values = 3.07 ± 0.20; 0.83 ± 0.12; 2.02 ± 0.27 and 5.83 ± 1.2 µM against LTB0016, PH8, Josefa and LV78 strains) whilst having low toxicity in the host macrophages (CC50 = 170.30 µM). We detected by flow cytometry that there is a greater expression of subtilisin in the amastigote form; however, PF-429242 had a low effect against this intracellular form with an IC50 of >100 µM for intracellular amastigotes, as well as against axenic amastigotes (94.12 ± 2.8 µM for the LV78 strain). In conclusion, even though PF-429242 does not affect the intracellular forms, this drug will serve as a tool to explore pharmacological and potentially leishmanicidal targets.
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Affiliation(s)
- Pollyanna Stephanie Gomes
- Laboratório de Imunologia Clínica, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz—Fiocruz, Rio de Janeiro 21040-360, Brazil; (P.S.G.); (M.P.D.C.); (P.d.A.M.); (A.M.d.F.-M.)
- Laboratório Interdisciplinar de Pesquisas Médicas, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, Brazil
- Laboratório de Imunofarmacologia, Instituto de Biofísica Carlos Chagas Filho IBCCF, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-170, Brazil
- Laboratório de Imunobiotecnologia, Instituto de Microbiologia Paulo de Goés, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
| | - Monique Pacheco Duarte Carneiro
- Laboratório de Imunologia Clínica, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz—Fiocruz, Rio de Janeiro 21040-360, Brazil; (P.S.G.); (M.P.D.C.); (P.d.A.M.); (A.M.d.F.-M.)
- Laboratório de Imunobiotecnologia, Instituto de Microbiologia Paulo de Goés, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
- Laboratório de Bioquímica e Biologia Molecular de Proteases, Instituto de Biofísica Carlos Chagas Filho IBCCF, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-170, Brazil; (A.G.); (A.P.C.d.A.L.)
| | - Patrícia de Almeida Machado
- Laboratório de Imunologia Clínica, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz—Fiocruz, Rio de Janeiro 21040-360, Brazil; (P.S.G.); (M.P.D.C.); (P.d.A.M.); (A.M.d.F.-M.)
- Laboratório Interdisciplinar de Pesquisas Médicas, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, Brazil
- Laboratório de Imunobiotecnologia, Instituto de Microbiologia Paulo de Goés, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
| | - Valter Viana de Andrade-Neto
- Laboratório de Bioquímica de Tripanossomatídeos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, Brazil;
| | - Alessandra Marcia da Fonseca-Martins
- Laboratório de Imunologia Clínica, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz—Fiocruz, Rio de Janeiro 21040-360, Brazil; (P.S.G.); (M.P.D.C.); (P.d.A.M.); (A.M.d.F.-M.)
- Laboratório Interdisciplinar de Pesquisas Médicas, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, Brazil
- Laboratório de Imunofarmacologia, Instituto de Biofísica Carlos Chagas Filho IBCCF, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-170, Brazil
- Laboratório de Imunobiotecnologia, Instituto de Microbiologia Paulo de Goés, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
| | - Amy Goundry
- Laboratório de Bioquímica e Biologia Molecular de Proteases, Instituto de Biofísica Carlos Chagas Filho IBCCF, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-170, Brazil; (A.G.); (A.P.C.d.A.L.)
| | | | | | - Ana Paula Cabral de Araujo Lima
- Laboratório de Bioquímica e Biologia Molecular de Proteases, Instituto de Biofísica Carlos Chagas Filho IBCCF, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-170, Brazil; (A.G.); (A.P.C.d.A.L.)
| | - Vítor Ennes-Vidal
- Laboratório de Estudos Integrados em Protozoologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, Brazil;
| | - Ana Carolina Rennó Sodero
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-170, Brazil; (J.V.M.P.d.S.); (A.C.R.S.)
| | - Salvatore Giovanni De-Simone
- Center for Technological Development in Health (CDTS), National Institute of Science and Technology for Innovation on Diseases Neglected Population (INCT-IDPN), FIOCRUZ, Rio de Janeiro 21040-900, Brazil;
- Epidemiology and Molecular Systematic Laboratory, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro 21040-900, Brazil
- Cellular and Molecular Biology Department, Biology Institute, Federal Fluminense University, Niterói 24020-141, Brazil
| | - Herbert L. de Matos Guedes
- Laboratório de Imunologia Clínica, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz—Fiocruz, Rio de Janeiro 21040-360, Brazil; (P.S.G.); (M.P.D.C.); (P.d.A.M.); (A.M.d.F.-M.)
- Laboratório Interdisciplinar de Pesquisas Médicas, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, Brazil
- Laboratório de Imunofarmacologia, Instituto de Biofísica Carlos Chagas Filho IBCCF, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-170, Brazil
- Laboratório de Imunobiotecnologia, Instituto de Microbiologia Paulo de Goés, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
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Machado PDA, Gomes PS, Midlej V, Coimbra ES, de Matos Guedes HL. PF-429242, a Subtilisin Inhibitor, Is Effective in vitro Against Leishmania infantum. Front Microbiol 2021; 12:583834. [PMID: 33584607 PMCID: PMC7876069 DOI: 10.3389/fmicb.2021.583834] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 01/06/2021] [Indexed: 01/16/2023] Open
Abstract
PF-429242 is an inhibitor of subtilisin, an important protease found in Leishmania. However, studies regarding the effect of PF-429242 on Leishmania are scarce. In this work we evaluated the antileishmanial effect of PF-429242 against Leishmania infantum and the mechanism involved in the death of the parasite. PF-429242 had low toxicity against mammalian cells (peritoneal macrophages) (CC50 = 189.07 μM) and presented activity against L. infantum promastigotes (IC50 = 2.78 μM) and intracellular amastigotes (IC50 = 14.07 μM), indicating selectivity toward the parasite. Transmission electron microscopy (TEM), as well as staining of L. infantum promastigotes with MitoTracker® Red, rhodamine 123 and MitoSOX, revealed that the mitochondria was a potential target of PF-429242. In addition, PF-429242 caused an accumulation of neutral lipids in promastigotes, which was demonstrated by Nile Red staining and TEM, and induced oxidative stress (H2DCFDA staining). Furthermore the formation of autophagic vacuoles in L. infantum promastigotes was observed by MDC staining and TEM. However, the killing induced by PF-429242 in L. infantum promastigotes appeared to be unrelated to apoptosis and/or necrosis as there was no phosphatidylserine externalization, DNA fragmentation or alterations in the permeability of the parasite plasma membrane, as assessed by annexin V-FITC, TUNEL and propidium iodide staining, respectively. The morphological and ultrastructural evaluation of the promastigotes by optical microscopy, scanning electron microscopy (SEM) and TEM, revealed the presence of parasites with flagellar defects. TEM analysis of the intracellular amastigotes indicated that mitochondrial damage and autophagy could also be involved in the death of these forms after treatment with PF-429242. In addition, PF-429242 treatment stimulated NO production from infected macrophage, but only at a high concentration (100 μM), as well as an increase of TNF levels after treatment with 10 μM of PF-429242. The compound did not stimulate ROS or IL-10 production. Together, these data highlight the antileishmanial potential of PF-429242, inducing several cellular alterations in the parasite, such as mitochondrial damage, neutral lipids accumulation, oxidative stress and autophagy which culminate in the death of L. infantum, as well as modulating host cellular responses that favor the development of an immune response against the parasite.
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Affiliation(s)
- Patrícia de Almeida Machado
- Laboratório Interdisciplinar de Pesquisas Médicas, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil.,Laboratório de Imunofarmacologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil.,Núcleo de Pesquisa em Parasitologia (NUPEP), Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil
| | - Pollyanna Stephanie Gomes
- Laboratório Interdisciplinar de Pesquisas Médicas, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil.,Laboratório de Imunofarmacologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Victor Midlej
- Laboratório de Ultraestrutura Celular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil
| | - Elaine Soares Coimbra
- Núcleo de Pesquisa em Parasitologia (NUPEP), Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil
| | - Herbert Leonel de Matos Guedes
- Laboratório Interdisciplinar de Pesquisas Médicas, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil.,Laboratório de Imunofarmacologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil.,UFRJ Campus Duque de Caxias Professor Geraldo Cidade - Universidade Federal do Rio de Janeiro, Duque de Caxias, Brazil.,Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
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Gomes PS, Tanghe S, Gallego-Delgado J, Conde L, Freire-de-Lima L, Lima AC, Freire-de-Lima CG, Lima Junior JDC, Moreira O, Totino P, Rodriguez A, Todeschini AR, Morrot A. Targeting the Hexosamine Biosynthetic Pathway Prevents Plasmodium Developmental Cycle and Disease Pathology in Vertebrate Host. Front Microbiol 2019; 10:305. [PMID: 30873136 PMCID: PMC6403127 DOI: 10.3389/fmicb.2019.00305] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Accepted: 02/05/2019] [Indexed: 11/13/2022] Open
Abstract
Cerebral malaria (CM) is a clinical syndrome involving irreversible and lethal signs of brain injury associated to infection by parasites of the genus Plasmodium. The pathogenesis of CM derives from infection-induced proinflammatory cytokines associated with cytoadherence of parasitized red blood cells to brain microvasculature. Glycoconjugates are very abundant in the surface of Plasmodium spp., and are critical mediators of parasite virulence in host–pathogen interactions. Herein, we show that 6-Diazo-5-oxo-L-norleucine (DON) therapeutically used for blocking hexosamine biosynthetic pathway leads to recovery in experimental murine cerebral malaria. DON-induced protection was associated with decreased parasitism, which severely reduced Plasmodium transmission to mosquitoes. These findings point to a potential use of DON in combination therapies against malaria.
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Affiliation(s)
- Pollyanna Stephanie Gomes
- Centro de Pesquisas em Tuberculose, Instituto de Microbiologia, Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Scott Tanghe
- Division of Parasitology, Department of Microbiology, New York University School of Medicine, New York City, NY, United States
| | - Julio Gallego-Delgado
- Division of Parasitology, Department of Microbiology, New York University School of Medicine, New York City, NY, United States
| | - Luciana Conde
- Centro de Pesquisas em Tuberculose, Instituto de Microbiologia, Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Leonardo Freire-de-Lima
- Instituto de Biofísica Carlos Chagas Filho IBCCF, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Célio Geraldo Freire-de-Lima
- Instituto de Biofísica Carlos Chagas Filho IBCCF, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | | | - Paulo Totino
- Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil
| | - Ana Rodriguez
- Division of Parasitology, Department of Microbiology, New York University School of Medicine, New York City, NY, United States
| | - Adriane Regina Todeschini
- Laboratório de Glicobiologia Estrutural e Funcional, Instituto de Biofísica Carlos Chagas Filho IBCCF, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Alexandre Morrot
- Centro de Pesquisas em Tuberculose, Instituto de Microbiologia, Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Laboratório de Imunoparasitologia, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil
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Maran N, Gomes PS, Freire-de-Lima L, Freitas EO, Freire-de-Lima CG, Morrot A. Host resistance to visceral leishmaniasis: prevalence and prevention. Expert Rev Anti Infect Ther 2016; 14:435-42. [DOI: 10.1586/14787210.2016.1160779] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Valente TAM, Silva DM, Gomes PS, Fernandes MH, Santos JD, Sencadas V. Effect of Sterilization Methods on Electrospun Poly(lactic acid) (PLA) Fiber Alignment for Biomedical Applications. ACS Appl Mater Interfaces 2016; 8:3241-3249. [PMID: 26756809 DOI: 10.1021/acsami.5b10869] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Medically approved sterility methods should be a major concern when developing a polymeric scaffold, mainly when commercialization is envisaged. In the present work, poly(lactic acid) (PLA) fiber membranes were processed by electrospinning with random and aligned fiber alignment and sterilized under UV, ethylene oxide (EO), and γ-radiation, the most common ones for clinical applications. It was observed that UV light and γ-radiation do not influence fiber morphology or alignment, while electrospun samples treated with EO lead to fiber orientation loss and morphology changing from cylindrical fibers to ribbon-like structures, accompanied to an increase of polymer crystallinity up to 28%. UV light and γ-radiation sterilization methods showed to be less harmful to polymer morphology, without significant changes in polymer thermal and mechanical properties, but a slight increase of polymer wettability was detected, especially for the samples treated with UV radiation. In vitro results indicate that both UV and γ-radiation treatments of PLA membranes allow the adhesion and proliferation of MG 63 osteoblastic cells in a close interaction with the fiber meshes and with a growth pattern highly sensitive to the underlying random or aligned fiber orientation. These results are suggestive of the potential of both γ-radiation sterilized PLA membranes for clinical applications in regenerative medicine, especially those where customized membrane morphology and fiber alignment is an important issue.
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Affiliation(s)
- T A M Valente
- Departamento de Engenharia Metalúrgica e Materiais, Faculdade de Engenharia, Universidade do Porto , Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - D M Silva
- Biosckin, Molecular, and Cell Therapies, SA. Parque Tecnológico da Maia-Tecmaia , Rua Eng.° Frederico Ulrich, 2650, 4470-605 Maia, Portugal
| | - P S Gomes
- Faculdade de Medicina Dentária, Universidade do Porto , Rua Dr. Manuel Pereira da Silva, 4200-393 Porto, Portugal
| | - M H Fernandes
- Faculdade de Medicina Dentária, Universidade do Porto , Rua Dr. Manuel Pereira da Silva, 4200-393 Porto, Portugal
| | - J D Santos
- Departamento de Engenharia Metalúrgica e Materiais, Faculdade de Engenharia, Universidade do Porto , Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
- CEMUC, Departamento de Engenharia Metalúrgica e Materiais, Faculdade de Engenharia, Universidade do Porto , Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - V Sencadas
- School of Mechanical, Materials, and Mechatronics Engineering, University of Wollongong , Wollongong, NSW 2522, Australia
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Morais DS, Fernandes S, Gomes PS, Fernandes MH, Sampaio P, Ferraz MP, Santos JD, Lopes MA, Sooraj Hussain N. Novel cerium doped glass-reinforced hydroxyapatite with antibacterial and osteoconductive properties for bone tissue regeneration. Biomed Mater 2015; 10:055008. [DOI: 10.1088/1748-6041/10/5/055008] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Faustino-Rocha AI, Rodrigues D, Ferreira R, Colaço B, Gomes PS, Pires MJ, Gama A, Oliveira PA. The effects of intense pulsed light in a mouse model of skin carcinogenesis. Br J Dermatol 2015; 174:216-8. [PMID: 26147791 DOI: 10.1111/bjd.14010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- A I Faustino-Rocha
- Department of Veterinary Sciences, School of Agrarian and Veterinary Sciences, University of Trás-os-Montes and Alto Douro, UTAD, 5001-911, Vila Real, Portugal.,Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes and Alto Douro, UTAD, 5001-911, Vila Real, Portugal
| | - D Rodrigues
- Department of Veterinary Sciences, School of Agrarian and Veterinary Sciences, University of Trás-os-Montes and Alto Douro, UTAD, 5001-911, Vila Real, Portugal
| | - R Ferreira
- Organic Chemistry of Natural Products and Agrifood (QOPNA), Mass Spectrometry Centre, Department of Chemistry, University of Aveiro, 3810-193, Aveiro, Portugal
| | - B Colaço
- Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes and Alto Douro, UTAD, 5001-911, Vila Real, Portugal.,Department of Zootechnics, School of Agrarian and Veterinary Sciences, University of Trás-os-Montes and Alto Douro, UTAD, 5001-911, Vila Real, Portugal
| | - P S Gomes
- Laboratory of Pharmacology and Cellular Biocompatibility, Faculty of Dental Medicine, University of Porto, UP, 4200-393, Porto, Portugal
| | - M J Pires
- Department of Veterinary Sciences, School of Agrarian and Veterinary Sciences, University of Trás-os-Montes and Alto Douro, UTAD, 5001-911, Vila Real, Portugal.,Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes and Alto Douro, UTAD, 5001-911, Vila Real, Portugal
| | - A Gama
- Department of Veterinary Sciences, School of Agrarian and Veterinary Sciences, University of Trás-os-Montes and Alto Douro, UTAD, 5001-911, Vila Real, Portugal.,Animal and Veterinary Research Centre (CECAV), School of Agrarian and Veterinary Sciences, University of Trás-os-Montes and Alto Douro, UTAD, 5001-911, Vila Real, Portugal
| | - P A Oliveira
- Department of Veterinary Sciences, School of Agrarian and Veterinary Sciences, University of Trás-os-Montes and Alto Douro, UTAD, 5001-911, Vila Real, Portugal.,Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes and Alto Douro, UTAD, 5001-911, Vila Real, Portugal
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Mata D, Amaral M, Fernandes AJS, Colaço B, Gama A, Paiva MC, Gomes PS, Silva RF, Fernandes MH. Diels-Alder functionalized carbon nanotubes for bone tissue engineering: in vitro/in vivo biocompatibility and biodegradability. Nanoscale 2015; 7:9238-9251. [PMID: 25928241 DOI: 10.1039/c5nr01829c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The risk-benefit balance for carbon nanotubes (CNTs) dictates their clinical fate. To take a step forward at this crossroad it is compulsory to modulate the CNT in vivo biocompatibility and biodegradability via e.g. chemical functionalization. CNT membranes were functionalised combining a Diels-Alder cycloaddition reaction to generate cyclohexene (-C6H10) followed by a mild oxidisation to yield carboxylic acid groups (-COOH). In vitro proliferation and osteogenic differentiation of human osteoblastic cells were maximized on functionalized CNT membranes (p,f-CNTs). The in vivo subcutaneously implanted materials showed a higher biological reactivity, thus inducing a slighter intense inflammatory response compared to non-functionalized CNT membranes (p-CNTs), but still showing a reduced cytotoxicity profile. Moreover, the in vivo biodegradation of CNTs was superior for p,f-CNT membranes, likely mediated by the oxidation-induced myeloperoxidase (MPO) in neutrophil and macrophage inflammatory milieus. This proves the biodegradability faculty of functionalized CNTs, which potentially avoids long-term tissue accumulation and triggering of acute toxicity. On the whole, the proposed Diels-Alder functionalization accounts for the improved CNT biological response in terms of the biocompatibility and biodegradability profiles. Therefore, CNTs can be considered for use in bone tissue engineering without notable toxicological threats.
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Affiliation(s)
- D Mata
- CICECO, Materials and Ceramic Eng. Dept., Univ. of Aveiro, 3810-193 Aveiro, Portugal.
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Durão SF, Gomes PS, Colaço BJ, Silva JC, Fonseca HM, Duarte JR, Felino AC, Fernandes MH. The biomaterial-mediated healing of critical size bone defects in the ovariectomized rat. Osteoporos Int 2014; 25:1535-45. [PMID: 24573401 DOI: 10.1007/s00198-014-2656-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 02/12/2014] [Indexed: 12/14/2022]
Abstract
UNLABELLED This study demonstrated an impaired biomaterial-mediated bone regeneration in a critical sized calvarial defect established within an ovariectomized rat model. Histological and microtomographic evidences were supported by an impaired osteoblastic gene expression and altered expression of estrogen receptors and adipogenic markers. INTRODUCTION This work aims to address the bone regeneration process in the ovariectomized rat model, by assessing a calvarial critical size defect implanted with a biocompatible bovine bone mineral graft. METHODS Animals were randomly divided into two groups: Ovx (bilateral ovariectomy) and Sham (control surgery). Following 8 weeks, all animals were submitted to a surgical bicortical craniotomy (5-mm circular critical size defect), which was filled with a biocompatible mineral graft. Animals were euthanized at 1, 3, and 6 months following graft implantation (n = 10), and results on the orthotopic bone regeneration process were blindly evaluated by radiographic, microtomographic, histological, histomorphometric, and gene expression techniques. RESULTS In the attained model, in both Sham and Ovx groups, the bone regenerative process was found to occur in a slow-paced manner. Likewise, a qualitative evaluation of the microtomographic and histological analysis, as well as quantitative data from histomorphometric indexes, revealed reduced bone regeneration in Ovx animals, at the assayed time points. Significant differences were attained at the 3 and 6 months. Gene expression analysis revealed a reduced expression of osteoblastic-related genes and an altered expression of estrogen receptors and adipogenic markers, within the regenerating bone of Ovx animals. CONCLUSIONS Due to the similarities between the osteoporotic animal model and the human condition of postmenopausal osteoporosis, it might be relevant to consider the potential clinical implication of the osteoporotic condition in the biomaterial-mediated bone tissue healing/regeneration process.
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Affiliation(s)
- S F Durão
- Surgery Department, Faculty of Dental Medicine, University of Porto, Rua Dr. Manuel Pereira da Silva, 4200-393, Porto, Portugal
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Mata D, Oliveira FJ, Ferro M, Gomes PS, Fernandes MH, Lopes MA, Silval RF. Multifunctional carbon nanotube/bioceramics modulate the directional growth and activity of osteoblastic cells. J Biomed Nanotechnol 2014; 10:725-43. [PMID: 24734525 DOI: 10.1166/jbn.2014.1749] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Biomaterials can still be reinvented to become simple and universal bone regeneration solutions. Following this roadmap, a bone graft of carbon nanotube (CNT)/glass/hydroxyapatite (HA) with controlled CNT agglomeration state was designed with multifunctionalities able to stimulate the bone cell phenotype. The preparation route, the mechanical and electrical behavior and the in vitro profiles of degradation and osteocompatibility were described. A non-destructive dynamic route was found to have a higher influence than the Diels-Alder functionalization one on controlling the CNT agglomerate state in the ceramic-matrix composite. Biologically safe CNT agglomerates, with diameter sizes below 3 microm homogenously distributed, were obtained in non-functionalized and functionalized composites. Yet, the lowest CNT damage and the highest mechanical and electrical properties were found for the non-functionalized materials. Even though that these composites present higher degradation rate at pH:3 than the ceramic matrix, the CNT agglomerates are released with safe diameter sizes. Also, non-functionalized composites allowed cellular adhesion and modulated the orientation of the cell growth, with a proliferation/differentiation relationship favoring osteoblastic functional activity. Findings offer further contributions for bone tissue engineering by showing that multifunctional bone grafts with high electroconductivity, and integrating CNT agglomerates with maximized interfacing area, allow the in situ control of bone cell functions.
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11
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Mata D, Oliveira FJ, Ferreira NM, Araújo RF, Fernandes AJS, Lopes MA, Gomes PS, Fernandes MH, Silva RF. Processing strategies for smart electroconductive carbon nanotube-based bioceramic bone grafts. Nanotechnology 2014; 25:145602. [PMID: 24622290 DOI: 10.1088/0957-4484/25/14/145602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Electroconductive bone grafts have been designed to control bone regeneration. Contrary to polymeric matrices, the translation of the carbon nanotube (CNT) electroconductivity into oxide ceramics is challenging due to the CNT oxidation during sintering. Sintering strategies involving reactive-bed pressureless sintering (RB + P) and hot-pressing (HP) were optimized towards prevention of CNT oxidation in glass/hydroxyapatite (HA) matrices. Both showed CNT retentions up to 80%, even at 1300 °C, yielding an increase of the electroconductivity in ten orders of magnitude relative to the matrix. The RB + P CNT compacts showed higher electroconductivity by ∼170% than the HP ones due to the lower damage to CNTs of the former route. Even so, highly reproducible conductivities with statistical variation below 5% and dense compacts up to 96% were only obtained by HP. The hot-pressed CNT compacts possessed no acute toxicity in a human osteoblastic cell line. A normal cellular adhesion and a marked orientation of the cell growth were observed over the CNT composites, with a proliferation/differentiation relationship favouring osteoblastic functional activity. These sintering strategies offer new insights into the sintering of electroconductive CNT containing bioactive ceramics with unlimited geometries for electrotherapy of the bone tissue.
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Affiliation(s)
- D Mata
- I3N, Physics Department, University of Aveiro, 3810-193 Aveiro, Portugal
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12
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Santos C, Gomes PS, Duarte JA, Franke RP, Almeida MM, Costa MEV, Fernandes MH. Relevance of the sterilization-induced effects on the properties of different hydroxyapatite nanoparticles and assessment of the osteoblastic cell response. J R Soc Interface 2012; 9:3397-410. [PMID: 22809851 DOI: 10.1098/rsif.2012.0487] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Hydroxyapatite (Hap) is a calcium phosphate with a chemical formula that closely resembles that of the mineral constituents found in hard tissues, thereby explaining its natural biocompatibility and wide biomedical use. Nanostructured Hap materials appear to present a good performance in bone tissue applications because of their ability to mimic the dimensions of bone components. However, bone cell response to individual nanoparticles and/or nanoparticle aggregates lost from these materials is largely unknown and shows great variability. This work addresses the preparation and characterization of two different Hap nanoparticles and their interaction with osteoblastic cells. Hap particles were produced by a wet chemical synthesis (WCS) at 37°C and by hydrothermal synthesis (HS) at 180°C. As the ultimate in vivo applications require a sterilization step, the synthesized particles were characterized 'as prepared' and after sterilization (autoclaving, 120°C, 20 min). WCS and HS particles differ in their morphological (size and shape) and physicochemical properties. The sterilization modified markedly the shape, size and aggregation state of WCS nanoparticles. Both particles were readily internalized by osteoblastic cells by endocytosis, and showed a low intracellular dissolution rate. Concentrations of WCS and HS particles less than 500 μg ml(-1) did not affect cell proliferation, F-actin cytoskeleton organization and apoptosis rate and increased the gene expression of alkaline phosphatase and BMP-2. The two particles presented some differences in the elicited cell response. In conclusion, WCS and HS particles might exhibit an interesting profile for bone tissue applications. Results suggest the relevance of a proper particle characterization, and the interest of an individual nanoparticle targeted research.
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Affiliation(s)
- C Santos
- Department of Materials and Ceramic Engineering, CICECO, University of Aveiro, 3810-193 Aveiro, Portugal
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13
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Bessa Pereira C, Gomes PS, Costa-Rodrigues J, Almeida Palmas R, Vieira L, Ferraz MP, Lopes MA, Fernandes MH. Equisetum arvense hydromethanolic extracts in bone tissue regeneration: in vitro osteoblastic modulation and antibacterial activity. Cell Prolif 2012; 45:386-96. [PMID: 22672309 DOI: 10.1111/j.1365-2184.2012.00826.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 03/26/2012] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVES Equisetum arvense preparations have long been used to promote bone healing. The aim of this work was to evaluate osteogenic and antibacterial effects of E. arvense hydromethanolic extracts. MATERIALS AND METHODS Dried aerial components of E. arvense were extracted using a mixture of methanol:water (1:1), for 26 days, yielding three extracts that were tested (10-1000 μg/ml) in human osteoblastic cells: E1, E2 and EM (a mixture of E1 and E2, 1:1). Cell cultures, performed on cell culture plates or over hydroxyapatite (HA) substrates, were assessed for osteoblastic markers. In addition, effects of the extracts on Staphylococcus aureus were addressed. RESULTS Solution E1 caused increased viability/proliferation and ALP activity at 50-500 μg/ml, and deleterious effects at levels ≥1000 μg/ml. E2 inhibited cell proliferation at levels ≥500 μg/ml. EM presented a profile between those observed with E1 and E2. In addition, E1, E2 and EM, 10-1000 μg/ml, inhibited expansion of S. aureus. Furthermore, E1, tested in HA substrates colonized with osteoblastic cells, causing increase in cell population growth (10-100 μg/ml). E1 also exhibited antibacterial activity against S. aureus cultured over HA. CONCLUSIONS Results showed that E. arvense extracts elicited inductive effects on human osteoblasts while inhibiting activity of S. aureus, suggesting a potentially interesting profile regarding bone regeneration strategies.
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Affiliation(s)
- C Bessa Pereira
- Laboratório de Farmacologia e Biocompatibilidade Celular, Faculdade de Medicina Dentária, Universidade do Porto, Porto, Portugal
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Lopes PP, Ferreira BJML, Gomes PS, Correia RN, Fernandes MH, Fernandes MHV. Silicate and borate glasses as composite fillers: a bioactivity and biocompatibility study. J Mater Sci Mater Med 2011; 22:1501-1510. [PMID: 21556978 DOI: 10.1007/s10856-011-4331-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Accepted: 04/27/2011] [Indexed: 05/30/2023]
Abstract
Composites filled with a silicate glass (CSi) and a new borate glass (CB) were developed and compared in terms of their in vitro behaviour both in acellular and cellular media. Acellular tests were carried out in SBF and the composites were characterized by SEM-EDS, XRD and ICP. Biocompatibility studies were investigated by in vitro cell culture with MG-63 osteoblast-like and human bone marrow cells. The growth of spherical calcium phosphate aggregates was observed in acellular medium on all composite surfaces indicating that these materials became potentially bioactive. The biological assessment resulted in a dissimilar behavior of the composites. The CSi demonstrated an inductive effect on the proliferation of cells. The cells showed a normal morphology and high growth rate when compared to standard culture plates. Contrarily, inhibition of cell proliferation occurred in the CB probably due to its high degradation rate, leading to high B and Mg ionic concentration in the cell culture medium.
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Affiliation(s)
- P P Lopes
- CICECO and Department of Ceramics and Glass Engineering, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
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15
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Affiliation(s)
- T A Rama
- Laboratório de Farmacologia e Biocompatibilidade Celular, Faculdade de Medicina Dentária, Universidade do Porto, Portugal
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16
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Gomes PS, Fernandes MH. Rodent models in bone-related research: the relevance of calvarial defects in the assessment of bone regeneration strategies. Lab Anim 2010; 45:14-24. [PMID: 21156759 DOI: 10.1258/la.2010.010085] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In vivo research with animal models has been a preferred experimental system in bone-related biomedical research since, by approximation, it allows relevant data gathering regarding physiological and pathological conditions that could be of use to establish more effective clinical interventions. Animal models, and more specifically rodent models, have been extensively used and have contributed greatly to the development and establishment of a wide range of translational approaches aiming to regenerate the bone tissue. In this regard, the calvarial defect model has found great application in basic and applied research, nonetheless the controversial rationalization for the use of critical size defects - defects that are unable to report spontaneous healing - or subcritical size defects in the proposed applications. Accordingly, this work aims to review the advantages and limitations of the use of rodent models in biomedical bone-related research, emphasizing the problematic issues of the use of calvarial critical and subcritical size defects. Additionally, surgical protocols for the establishment of both defects in rat calvarial bone, as well as the description and exemplification of the most frequently used techniques to access the bone tissue repair, are portrayed.
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Affiliation(s)
- P S Gomes
- Laboratory of Pharmacology and Cellular Biocompatibility, Faculty of Dental Medicine, U Porto, R Dr Manuel Pereira da Silva, 4200-393 Porto, Portugal.
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17
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Silva MA, Gomes PS, Vila M, Lopes MA, Santos JD, Silva RF, Fernandes MH. New titanium and titanium/hydroxyapatite coatings on ultra-high-molecular-weight polyethylene—
in vitro
osteoblastic performance. Biomed Mater 2010; 5:35014. [DOI: 10.1088/1748-6041/5/3/035014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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18
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Meirelles C, Candido T, Gomes PS. Effects of short-term very low-carbohydrate or conventional diet on strength performance. J Sports Med Phys Fitness 2010; 50:189-195. [PMID: 20585297] [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: 05/29/2023]
Abstract
AIM Weight reduction strategies usually include diet and regular physical activity. A very low-carbohydrate and high protein diet (VLCD) may be preferred instead of a low energy conventional diet (CONV). The effects of VLCD on strength performance are yet to be understood. Aim of the study is to determine the effects of two different restrictive diets on strength performance. METHODS Sedentary women were assigned to either a VLCD (<40 g carbohydrate; n=12) or a CONV diet (500 to 800 kcal restrictive; 48%, 22% and 30% from carbohydrate, protein and fat, respectively; n=12). Knee extension isokinetic strength tests (3 yen 15 reps at 60 degrees .s-1, with 90 or 180 s rest interval between sets) were performed prior and after a one week diet period. RESULTS Both groups reduced body mass (VLCD: -2.6+/-1.0% vs. CONV: -1.9+/-1.3%; P<0.05), with no between diets effect. The sum of the total work in three sets (ATW) was 4850+/-1002 J vs. 4801+/-973 J with 90 s rest interval, and 4812+/-1174 J vs. 4812+/-1210 J with 180 s rest interval, respectively, in the pre vs. post-VLCD period. For CONV, values were 4709+/-729 J vs. 4530+/-996 J with 90 s rest interval, and 4760+/-732 J vs. 4816+/-702 J with 180 s rest interval, respectively, in the pre vs. post-CONV treatment. No significant differences were detected in the ATW between groups. CONCLUSION Short-term hypoenergetic diets, irrespective of the carbohydrate content, seem to reduce significantly body mass, but do not impair acute strength performance.
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Affiliation(s)
- C Meirelles
- Laboratory Crossbridges, Center for Interdisciplinary Research in Health, Department of Physical Education, Universidade Gama Filho, Rio de Janeiro, Brazil
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19
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Silva Marques JM, Gomes PS, Silva MA, Silvério Cabrita AM, Santos JD, Fernandes MH. Growth and phenotypic expression of human endothelial cells cultured on a glass-reinforced hydroxyapatite. J Mater Sci Mater Med 2009; 20:725-731. [PMID: 18987948 DOI: 10.1007/s10856-008-3628-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2008] [Accepted: 10/16/2008] [Indexed: 05/27/2023]
Abstract
Glass-reinforced hydroxyapatite composites (GR-HA) are bone regenerative materials that are characterized by their increased mechanical properties, when compared to synthetic hydroxyapatite. Bonelike is a GR-HA that is a result of the addition of a CaO-P(2)O(5) based glass to a HA matrix. This biomaterial has been successfully applied in clinical bone regenerative applications. This work aims to evaluate the ability of Bonelike to support the adhesion, proliferation and phenotypic expression of human endothelial cells, aiming to establish new bone tissue engineering pre-endothelialization strategies. Bonelike discs, regardless of being submitted to a pre-immersion treatment with culture medium, were seeded with first passage human umbilical vein endothelial cells, and characterized regarding proliferation and differentiation events. Pre-immersed Bonelike allowed the adhesion, proliferation and phenotype expression of endothelial cells. Seeded materials presented positive immunofluorescent staining for PECAM-1 and a tendency for the formation of cord-like arrangements under angiogenesis-stimulating conditions, although, compared to standard culture plates, a slight decreased cell growth was observed. In this way, Bonelike may be a suitable candidate for pre-endothelialization approaches in bone tissue engineering applications.
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Affiliation(s)
- J M Silva Marques
- Cooperativa de Ensino Superior Egas Moniz, Monte de Caparica, Portugal
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20
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Amaral M, Gomes PS, Lopes MA, Santos JD, Silva RF, Fernandes MH. Cytotoxicity evaluation of nanocrystalline diamond coatings by fibroblast cell cultures. Acta Biomater 2009; 5:755-63. [PMID: 18819854 DOI: 10.1016/j.actbio.2008.08.015] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2008] [Revised: 07/01/2008] [Accepted: 08/26/2008] [Indexed: 12/01/2022]
Abstract
The cytotoxicity profile of nanocrystalline diamond (NCD) coatings on a Si(3)N(4) ceramic was investigated. This material is envisaged to have biomedical dental applications such as burrs and surgical instruments. Two fibroblast cell culture systems were used to address the cytotoxicity of NCD-coated samples: L929 cells (a mouse permanent cell line) and human gingival fibroblasts. Cell behavior was evaluated in terms of cell adhesion, cell viability/proliferation (mitochondrial function, MTT assay) and the pattern of cell growth. Fibroblast cell behavior on standard polystyrene culture plates was used as control, as Si(3)N(4) substrates have previously been shown to be biocompatible. NCD coatings provided a suitable surface for cell attachment, spreading and proliferation. Human gingival cells showed a homogeneous cytoplasm spreading, a flattened elongated morphology and a typical parallel alignment on confluent cultures. In comparison, L929 cells denoted a lower cytoplasm expansion, a heterogeneous spreading but a higher proliferation rate. For both cells, after few days, the NCD coating was completely covered with continuous cell layers. As compared to standard polystyrene culture plates, no deleterious or cytotoxic responses were observed with L929 and human fibroblast cell cultures, and in both a slight enhancement in cell proliferation was observed. In addition, the seeded NCD film allowed reproduction of the typical features of the two cell culture systems tested, further suggesting the lack of cytotoxicity of this coating.
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Affiliation(s)
- M Amaral
- CICECO, Department of Ceramics and Glass Engineering, University of Aveiro, 3810-193 Aveiro, Portugal.
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21
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Marra A, Lewi D, Lanzoni V, Wey SB, Odashiro LN, Gomes PS, Silva E. Lactic acidosis and antiretroviral therapy: a case report and literature review. Braz J Infect Dis 2000; 4:151-5. [PMID: 10934499] [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: 02/17/2023] Open
Abstract
Antiretrovirals, particularly nucleoside analogue reverse transcriptase inhibitors (RTIs) - DDI, 3TC and D4T, are widely used to effectively control human immunodeficiency virus (HIV) infection. These drugs have several adverse effects including anemia, peripheral neuropathy, pancreatitis and, on rare occasions, lactic acidosis. We describe the case of a 39 year old patient who had severe lactic acidosis after receiving stavudine (D4T) and didanosine (DDI) for an 8 month period. She had never manifested an opportunistic infection and presented a CD4 count of 378 cells/mm3 and an undetectable viral load (< 400 copies/ml). The purpose of the following report is to alert clinicians and infectious diseases specialists to the occurrence of lactic acidosis in asymptomatic HIV patients receiving antiretrovirals for long periods of time.
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Affiliation(s)
- A Marra
- Medical School of S'o Paulo, Federal University of São Paulo, SP, Brazil.
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22
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Bhambhani YN, Eriksson P, Gomes PS. Transfer effects of endurance training with the arms and legs. Med Sci Sports Exerc 1991; 23:1035-41. [PMID: 1943623] [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: 12/29/2022]
Abstract
The purpose of this study was to examine whether endurance training in the form of arm or leg cycling resulted in significant transfer effects when exercise was performed with the untrained muscle group. Sixteen middle-aged male volunteers completed 24 training sessions over 8 wk on either an arm cycle ergometer (AG, N = 8, mean age = 35.2 +/- 6.6 yr) or a leg cycle ergometer (LG, N = 8, mean age = 41.0 +/- 4.7 yr). The two groups were initially equated for their pre-training peak oxygen uptake (pVO2) determined during leg cycling (44.5 +/- 5.0 and 43.8 +/- 7.7 ml.kg-1.min-1 for the AG and LG, respectively). Training was performed at an intensity that was mid-way between the pre-training ventilatory threshold (VT) and the pVO2 for both cycling methods. Significant increases (P less than .05) were observed in the relative values of the oxygen uptake at the VT and the pVO2 as a result of both these methods of training, but these elevations were specific to the muscle groups that were trained. This specificity of training was also evident in the cardiorespiratory and metabolic measurements obtained during submaximal steady state exercise performed at the power output corresponding to the pre-training VT during arm and leg exercise. Hence, it was concluded that improvements in exercise performance resulting from short-term aerobic training with the arms or legs in middle-aged males with relatively high aerobic powers are due primarily to peripheral adaptations in the trained muscles.
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Affiliation(s)
- Y N Bhambhani
- Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Canada
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23
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Bhambhani YN, Clarkson HM, Gomes PS. Axillary crutch walking: effects of three training programs. Arch Phys Med Rehabil 1990; 71:484-9. [PMID: 2350217] [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: 12/31/2022]
Abstract
This study compared the effects of three different training programs on physiologic and perceptual responses during axillary crutch walking (ACW) for a distance of 1 km at self-selected speeds in healthy women. Forty subjects completed 18 training sessions in six weeks according to one of the following regimens: (1) 20 minutes of aerobic arm ergometer training at 50% of peak oxygen consumption determined during arm ergometry; (2) isotonic strength and endurance training of the upper extremities with free weights; or (3) axillary crutching at self-selected speeds for 20 minutes on a rectangular indoor course. In comparison with a control group that did not do any systematic training, all three training groups significantly increased their self-selected ACW speeds after training. This also resulted in a significant increase in their heart rates during ambulation. However, no significant changes were observed in oxygen consumption at the faster ACW speeds, suggesting that the training regimens were effective in improving the metabolic efficiency of ACW. Ratings of perceived exertion were significantly lowered for the three training groups even though cardiorespiratory stress was significantly elevated. No significant differences were observed between the three training programs for any of the variables examined. Since heart rate is a reliable indicator of myocardial oxygen uptake, it was recommended that (1) individuals should be screened for cardiovascular problems before axillary crutches are prescribed as a mode of ambulation, and (2) they should be advised to reduce the speed of ambulation because of the high degree of cardiovascular stress associated with this activity.
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Affiliation(s)
- Y N Bhambhani
- Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Canada
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Bhambhani YN, Gomes PS, Wheeler G. Physiologic and perceptual responses during treadmill running with ankle weights. Arch Phys Med Rehabil 1990; 71:231-5. [PMID: 2317142] [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: 12/31/2022]
Abstract
This study examined the effects of ankle weighting on physiologic and perceptual responses during treadmill running in seven healthy, female recreational runners with a mean maximal aerobic power of 48.4 +/- 4.0 ml/kg/min. Each subject completed four experimental one-mile runs at individually selected treadmill running speeds with 0, 1.6, 3.2 and 4.8 kg weights on their ankles. The subjects selected a speed at which they would run (train) if their objectives were to significantly improve cardiovascular function and induce weight loss. Metabolic and cardiovascular responses were continuously monitored, and ratings of perceived exertion were recorded near the end of the activity. During the unweighted run, the subjects selected a running speed of 6.87 +/- 0.63 mph which resulted in a net energy expenditure of 0.153 kcal/kg/min or 1.34 +/- 0.16 kcal/kg/mile. This corresponded to a training intensity of 76.3% +/- 5.1% of maximum oxygen consumption or 88.1% +/- 9.7% of maximum heart rate. Addition of weight to the ankles caused a significant decrease (p less than .05) in the running speed selected and, therefore, did not result in any significant changes (p greater than .05) in the rate of oxygen consumption, heart rate or ratings of perceived exertion when compared to the unweighted condition. These observations are in contrast to previous studies on ankle weighting which were conducted at fixed treadmill running speeds. However, the use of ankle weights did have a tendency to increase gross and net energy expenditure of running when values were expressed in kcal/mile because of slower self-selected running speeds under these conditions. This increase in energy expenditure could be of physiologic significance if running with ankle weights was performed on a regular basis at a fixed distance.
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Affiliation(s)
- Y N Bhambhani
- Department of Occupational Therapy, University of Alberta, Edmonton, Canada
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