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Rutkunas V, Borusevicius R, Balciunas E, Jasinskyte U, Alksne M, Simoliunas E, Zlatev S, Ivanova V, Bukelskiene V, Mijiritsky E. The Effect of UV Treatment on Surface Contact Angle, Fibroblast Cytotoxicity, and Proliferation with Two Types of Zirconia-Based Ceramics. Int J Environ Res Public Health 2022; 19:11113. [PMID: 36078826 PMCID: PMC9518570 DOI: 10.3390/ijerph191711113] [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] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/31/2022] [Accepted: 09/02/2022] [Indexed: 06/15/2023]
Abstract
UV photofunctionalization of Zirconia-based materials for abutment fabrication is a promising approach that might influence the formation of a sound peri-implant seal, thus promoting long-term soft and hard tissue implant integration. This study aimed to evaluate the effect of UV treatment of test specimens made by two different ZnO2-based ceramic materials on the hydrophilicity, cell cytotoxicity, and proliferation of human gingival fibroblasts (HGFs). Two Zirconia-based materials, high-translucent and ultra-translucent multi-layered Zirconia (Katana, Kuraray Noritake, Japan), were used to prepare a total of 40 specimens distributed in two equally sized groups based on the material (n = 20). The same surface finishing protocol was applied for all specimens, as suggested by the manufacturer. Half the specimens from each group were treated with UV-C light for 48 h. Water contact angle (WCA), fibroblast cytotoxicity, and proliferation were investigated. The WCA values for the high-translucent Zirconia ranged from 69.9° ± 6.4° to 73.7° ± 13.9° for the treated/non-treated specimens and from 79.5° ± 12.8° to 83.4° ± 11.4° for the ultra-translucent multi-layered Zirconia, respectively. However, the difference was insignificant (F(16) = 3.50, p = 0.292). No significant difference was observed for the fibroblast cytotoxicity test. The results for proliferation revealed a significant difference, which was material-dependent (F(8) = 9.58, p = 0.005). We found that UV surface photofunctionalization of ZrO2-based materials alters the human gingival fibroblast cell viability, which might produce favourable results for cell proliferation.
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Affiliation(s)
- Vygandas Rutkunas
- Institute of Odontology, Faculty of Medicine, Vilnius University, 03101 Vilnius, Lithuania
| | - Rokas Borusevicius
- Institute of Odontology, Faculty of Medicine, Vilnius University, 03101 Vilnius, Lithuania
| | - Evaldas Balciunas
- Institute of Biochemistry, Life Sciences Center, Vilnius University, 03101 Vilnius, Lithuania
| | - Urte Jasinskyte
- Institute of Biochemistry, Life Sciences Center, Vilnius University, 03101 Vilnius, Lithuania
| | - Milda Alksne
- Institute of Biochemistry, Life Sciences Center, Vilnius University, 03101 Vilnius, Lithuania
| | - Egidijus Simoliunas
- Institute of Biochemistry, Life Sciences Center, Vilnius University, 03101 Vilnius, Lithuania
| | - Stefan Zlatev
- CAD/CAM Center of Dental Medicine at the Research Institute, Medical University of Plovdiv, 4000 Plovdiv, Bulgaria
| | - Vasilena Ivanova
- Oral Surgery Department, Faculty of Dental Medicine, Medical University of Plovdiv, 4000 Plovdiv, Bulgaria
| | - Virginija Bukelskiene
- Institute of Biochemistry, Life Sciences Center, Vilnius University, 03101 Vilnius, Lithuania
| | - Eitan Mijiritsky
- Head and Neck Maxillofacial Surgery, Tel-Aviv Sourasky Medical Center, Department of Otolaryngology, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv 699350, Israel
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Hasiuk PA, Ramus М, Vorobets A, Tkachenko I, Dzetsiukh T, Kalashnikov D, Rosolovska S. COMPARATIVE EVALUATION OF HISTOTOXICITY INDICATORS OF METAL ALLOYS FOR THE MANUFACTURE OF METAL CERAMIC DENTAL CONSTRUCTIONS. Wiad Lek 2021; 74:2100-2104. [PMID: 34725283] [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] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
OBJECTIVE The aim: To carry out a comparative assessment of metal alloys for the manufacture of metal-ceramic constructions of dentures by determining the indicator of their histotoxicity. PATIENTS AND METHODS Materials and methods: To identify the effect of metal alloys on cobalt and nickel bases on the tissue of organism, we carried out an experimental-morphological study of standard samples of metal alloys "Shot-alloy", "Remanium-2000", "Cerium", "Dent-NCB", "Cellite-N". RESULTS Results: A careful histological analysis of the capsules formed around the metal alloy samples during two periods of the experiment showed that the healing time of the subcutaneous tissue was not the same. The most complete healing, that is, the formation of mature fibrous connective tissue, occurred during the implantation of the cobaltbased alloy "Remanium-2000" and the capsule formed at the end of the experiment around the implanted sample from the "Shot-alloy" alloy, and during the implantation of the "Cerium" alloy, healing the wound surface and the formation of a connective tissue capsule occurs fully than in previous cases. CONCLUSION Conclusions: The analysis of the performed experiment testifies in favor of the point of view that the speed and quality of healing of damaged subcutaneous tissue upon the introduction of implanted research alloys depend largely on the individual chemical components that make up the alloys, or on their combination.
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Affiliation(s)
- Petro A Hasiuk
- I. HORBACHEVSKY TERNOPIL NATIONAL MEDICAL UNIVERSITY, TERNOPIL, UKRAINE
| | | | - Anna Vorobets
- I. HORBACHEVSKY TERNOPIL NATIONAL MEDICAL UNIVERSITY, TERNOPIL, UKRAINE
| | | | - Tetiana Dzetsiukh
- I. HORBACHEVSKY TERNOPIL NATIONAL MEDICAL UNIVERSITY, TERNOPIL, UKRAINE
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Svartz G, Aronzon C, Pérez Catán S, Soloneski S, Pérez Coll C. Oxidative stress and genotoxicity in Rhinella arenarum (Anura: Bufonidae) tadpoles after acute exposure to Ni-Al nanoceramics. Environ Toxicol Pharmacol 2020; 80:103508. [PMID: 33011327 DOI: 10.1016/j.etap.2020.103508] [Citation(s) in RCA: 1] [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: 12/23/2019] [Revised: 08/25/2020] [Accepted: 09/28/2020] [Indexed: 06/11/2023]
Abstract
The employ of nanomaterials (NMs) has exponentially grown due to the large number of technological advances in industrial, pharmaceutical and medical areas. That is the case of alumina (Al) nanoparticles which are extensively employed as support in heterogeneous catalysis processes. However, these NMs can cause great toxicity because of their ubiquitous properties, such as extremely small size and high specific surface area. So, it is required to assess the potential deleterious effects of these NMs on living organisms. In the present study, we analyze the oxidative stress and genotoxic potential of a nanoceramic catalyst Ni/<gamma>-Al2O3 (NC) and the NMs involved in their synthesis, <gamma>-Al2O3 support (SPC) and NiO/<gamma>-Al2O3 precursor (PC) on Rhinella arenarum larvae. Biomarkers of oxidative stress and genotoxic damage were measured in tadpoles exposed to 5 and 25 mg/L of each NMs for 96 h. The results indicated an inhibition of catalase activity in tadpoles exposed to both concentrations of PC and to 25 mg/L of SPC and NC. Moreover, both exposure concentrations of PC and NC significantly inhibited superoxide dismutase activity. Exposure to the three NMs caused inhibition of glutathione S-transferase activity, but there were no significant variations in reduced glutathione levels. Oxidative stress damage (lipid peroxidation) was observed in tadpoles treated with 25 mg/L PC, while the other treatments did not produce alterations. The MNs frequency significantly increased in larvae exposed to 25 mg/L PC indicating irreversible genotoxic damage. The results show that these NMs exert genotoxic effects and antioxidant defense system disruption in R. arenarum larvae.
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Affiliation(s)
- Gabriela Svartz
- Instituto de Investigación e Ingeniería Ambiental, UNSAM, CONICET, 3iA, Campus Miguelete, 25 de mayo y Francia (C1650), San Martín, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Carolina Aronzon
- Instituto de Investigación e Ingeniería Ambiental, UNSAM, CONICET, 3iA, Campus Miguelete, 25 de mayo y Francia (C1650), San Martín, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | | | - Sonia Soloneski
- Cátedra de Citología, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, Calle 64 Nº 3, B1904AMA La Plata, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Cristina Pérez Coll
- Instituto de Investigación e Ingeniería Ambiental, UNSAM, CONICET, 3iA, Campus Miguelete, 25 de mayo y Francia (C1650), San Martín, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
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Bessa MJ, Brandão F, Viana M, Gomes JF, Monfort E, Cassee FR, Fraga S, Teixeira JP. Nanoparticle exposure and hazard in the ceramic industry: an overview of potential sources, toxicity and health effects. Environ Res 2020; 184:109297. [PMID: 32155489 DOI: 10.1016/j.envres.2020.109297] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [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: 05/15/2019] [Revised: 02/22/2020] [Accepted: 02/23/2020] [Indexed: 06/10/2023]
Abstract
The ceramic industry is an industrial sector of great impact in the global economy that has been benefiting from advances in materials and processing technologies. Ceramic manufacturing has a strong potential for airborne particle formation and emission, namely of ultrafine particles (UFP) and nanoparticles (NP), meaning that workers of those industries are at risk of potential exposure to these particles. At present, little is known on the impact of engineered nanoparticles (ENP) on the environment and human health and no established Occupational Exposure Limits (OEL) or specific regulations to airborne nanoparticles (ANP) exposure exist raising concerns about the possible consequences of such exposure. In this paper, we provide an overview of the current knowledge on occupational exposure to NP in the ceramic industry and their impact on human health. Possible sources and exposure scenarios, a summary of the existing methods for evaluation and monitoring of ANP in the workplace environment and proposed Nano Reference Values (NRV) for different classes of NP are presented. Case studies on occupational exposure to ANP generated at different stages of the ceramic manufacturing process are described. Finally, the toxicological potential of intentional and unintentional ANP that have been identified in the ceramic industry workplace environment is discussed based on the existing evidence from in vitro and in vivo inhalation toxicity studies.
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Affiliation(s)
- Maria João Bessa
- Instituto Nacional de Saúde Doutor Ricardo Jorge, Departamento de Saúde Ambiental, Porto, Portugal; EPIUnit - Instituto de Saúde Pública, Universidade do Porto, Porto, Portugal; Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal.
| | - Fátima Brandão
- Instituto Nacional de Saúde Doutor Ricardo Jorge, Departamento de Saúde Ambiental, Porto, Portugal; EPIUnit - Instituto de Saúde Pública, Universidade do Porto, Porto, Portugal.
| | - Mar Viana
- Institute of Environmental Assessment and Water Research (IDÆA-CSIC), Barcelona, Spain.
| | - João F Gomes
- CERENA, Centro de Recursos Naturais e Ambiente/Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal; ISEL - Instituto Superior de Engenharia de Lisboa, Lisboa, Portugal.
| | - Eliseo Monfort
- Institute of Ceramic Technology (ITC), Universitat Jaume I, 12006, Castellón, Spain.
| | - Flemming R Cassee
- National Institute for Public Health and the Environment, Bilthoven, the Netherlands; Institute for Risk Assessment Studies, Utrecht University, Utrecht, the Netherlands.
| | - Sónia Fraga
- Instituto Nacional de Saúde Doutor Ricardo Jorge, Departamento de Saúde Ambiental, Porto, Portugal; EPIUnit - Instituto de Saúde Pública, Universidade do Porto, Porto, Portugal.
| | - João Paulo Teixeira
- Instituto Nacional de Saúde Doutor Ricardo Jorge, Departamento de Saúde Ambiental, Porto, Portugal; EPIUnit - Instituto de Saúde Pública, Universidade do Porto, Porto, Portugal.
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Svartz G, Sandoval MT, Gosatti M, Perez Catán S, Pérez Coll C. Lethality, neurotoxicity, morphological, histological and cellular alterations of Ni-Al nanoceramics on the embryo-larval development of Rhinella arenarum. Environ Toxicol Pharmacol 2019; 69:36-43. [PMID: 30953932 DOI: 10.1016/j.etap.2019.03.020] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 03/01/2019] [Accepted: 03/26/2019] [Indexed: 06/09/2023]
Abstract
Alumina nanoparticles (NP-Al2O3) are widely used but their environmental effects are unknown, so they can become potentially dangerous. The aim of this study was to evaluate the toxicity of a nanoceramic catalyst Ni/γ-Al2O3 (NC) and NPs involved in their synthesis, γ-Al2O3 support (SPC) and NiO/γ-Al2O3 precursor (PC) on Rhinella arenarum embryo-larval development. The NPs toxicity significantly increased over time obtaining a similar sensitivity to PC and NC (336 h-LC50 = 4.03 and 5.11 mg/L respectively) and very low sensitivity to SPC (336 h-LC50 = 90.83 mg/L). Embryos exposed to SPC and PC exhibited general underdevelopment, axial flexures and behavioral alterations. Pharyngeal and intestinal epithelia alterations at the level of cell surface as dissociation, apoptosis and numerous lysosomes were observed at light and transmission electronic microscopy. Images of scanning electron microscope with backscattered electron detector revealed the presence of nickel in the intestinal epithelium. The increased toxicity of PC could be due to the presence of Ni as oxide which could interfere with vital functions such as breathing and feeding. Taking into account the exponential production and use of these NPs it is expected that their pollution levels will considerably increase and amphibians will be more exposed and at higher risk.
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Affiliation(s)
- Gabriela Svartz
- Instituto de Investigación e Ingeniería Ambiental-CONICET, Universidad Nacional de San Martin, Av. 25 de Mayo y Francia (1650), San Martín, Buenos Aires, Argentina; CONICET, Argentina
| | - Maria Teresa Sandoval
- Laboratorio de Herpetología, Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste, Av libertad 5470 (3400) Corrientes, Argentina
| | - Marina Gosatti
- Centro Atómico Bariloche, Complejo Tecnológico Pilcaniyeu, Comisión Nacional de Energía Atómica, Centro Atómico Bariloche, Av. E. Bustillo 9500 (8400), Bariloche, Rio Negro, Argentina
| | - Soledad Perez Catán
- Centro Atómico Bariloche, Complejo Tecnológico Pilcaniyeu, Comisión Nacional de Energía Atómica, Centro Atómico Bariloche, Av. E. Bustillo 9500 (8400), Bariloche, Rio Negro, Argentina
| | - Cristina Pérez Coll
- Instituto de Investigación e Ingeniería Ambiental-CONICET, Universidad Nacional de San Martin, Av. 25 de Mayo y Francia (1650), San Martín, Buenos Aires, Argentina; CONICET, Argentina.
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Shim JS, Kim HC, Park SI, Yun HJ, Ryu JJ. Comparison of Various Implant Provisional Resin Materials for Cytotoxicity and Attachment to Human Gingival Fibroblasts. Int J Oral Maxillofac Implants 2019; 34:390-396. [PMID: 30883618 DOI: 10.11607/jomi.6707] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE The aim of this study was to evaluate the responses of human gingival fibroblast (HGF-1) in contact with provisional materials with various chemical compositions and fabricated using different methods. MATERIALS AND METHODS A total of 210 specimens in eight experimental groups were used. Groups were divided by chemical compositions (poly[ethyl methacrylate], poly[methyl methacrylate], bis-acryl, and hybrid ceramic) and fabricating methods (direct, indirect, and computer-aided design/computer-aided manufacturing [CAD/CAM]). To evaluate the surface characteristics of each group, roughness, water contact angle, and degree of conversion were measured. The responses of HGF-1 to provisional materials were evaluated with cytotoxicity and cell attachment assay. The roughness, surface energy, degree of conversion, level of cytotoxicity, and cell attachment were compared between groups using one-way analysis of variance (ANOVA) and Tukey's multiple comparison (α = .05). RESULTS The poly(ethyl methacrylate)-direct/indirect and poly(methyl methacrylate)-direct/indirect groups showed higher roughness than the bis-acryl-direct/indirect, poly(methyl methacrylate)-CAD/CAM, and hybrid ceramic-CAD/CAM groups with statistical significance (P < .05). The poly(ethyl methacrylate)-direct group showed the significantly highest water contact angle, and the hybrid ceramic-CAD/CAM group showed the lowest water contact angle (P < .05). The groups that used indirect fabrication methods showed a higher degree of conversion than those that used direct fabrication methods, regardless of chemical composition (P < .05). The poly(ethyl methacrylate) groups showed significantly lower cell viability than the other groups regardless of fabricating methods (P < .05). The poly(ethyl methacrylate)-direct method group showed the lowest cell attachment, and the hybrid ceramic-CAD/CAM method group showed the highest cell attachment (P < .05). CONCLUSION Poly(methyl methacrylate) and bis-acryl have lower cytotoxicity to HGF-1 than poly(ethyl methacrylate). Indirect fabrication and CAD/CAM are recommended to prevent residual monomer and achieve high cell attachment. To use direct fabrication methods, the auto-mix system is beneficial for the favorable cell response, as it derives a smooth surface.
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Burdette MK, Bandera YP, Zhang E, Trofimov A, Dickey A, Foulger I, Kolis JW, Cannon KE, Bartley AF, Dobrunz LE, Bolding MS, McMahon L, Foulger SH. Organic Fluorophore Coated Polycrystalline Ceramic LSO:Ce Scintillators for X-ray Bioimaging. Langmuir 2019; 35:171-182. [PMID: 30518207 DOI: 10.1021/acs.langmuir.8b03129] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The current effort demonstrates that lutetium oxyorthosilicate doped with 1-10% cerium (Lu2SiO5:Ce, LSO:Ce) radioluminescent particles can be coated with a single dye or multiple dyes and generate an effective energy transfer between the core and dye(s) when excited via X-rays. LSO:Ce particles were surface modified with an alkyne modified naphthalimide (6-piperidin-1-yl-2-prop-2-yn-1-yl-1 H-benzo[ de]isoquinoline-1,3-(2 H)-dione, AlNap) and alkyne modified rhodamine B ( N-(6-diethylamino)-9-{2-[(prop-2-yn-1-yloxy)carbonyl]phenyl}-3 H-xanthen-3-ylidene)- N-ethylethanaminium, AlRhod) derivatives to tune the X-ray excited optical luminescence from blue to green to red using Förster Resonance Energy Transfer (FRET). As X-rays penetrate tissue much more effectively than UV/visible light, the fluorophore modified phosphors may have applications as bioimaging agents. To that end, the phosphors were incubated with rat cortical neurons and imaged after 24 h. The LSO:Ce surface modified with AlNap was able to be successfully imaged in vitro with a low-output X-ray tube. To use the LSO:Ce fluorophore modified particles as imaging agents, they must not induce cytotoxicity. Neither LSO:Ce nor LSO:Ce modified with AlNap showed any cytotoxicity toward normal human dermal fibroblast cells or mouse cortical neurons, respectively.
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Affiliation(s)
- Mary K Burdette
- Department of Materials Science and Engineering , Clemson University , Clemson , South Carolina 29634 , United States
- Center for Optical Materials Science and Engineering Technologies , Clemson University , Anderson , South Carolina 29625 , United States
| | - Yuriy P Bandera
- Department of Materials Science and Engineering , Clemson University , Clemson , South Carolina 29634 , United States
- Center for Optical Materials Science and Engineering Technologies , Clemson University , Anderson , South Carolina 29625 , United States
| | - Eric Zhang
- Department of Materials Science and Engineering , Clemson University , Clemson , South Carolina 29634 , United States
- Center for Optical Materials Science and Engineering Technologies , Clemson University , Anderson , South Carolina 29625 , United States
| | - Artem Trofimov
- Department of Materials Science and Engineering , Clemson University , Clemson , South Carolina 29634 , United States
| | - Ashley Dickey
- Department of Chemistry , Clemson University , Clemson , South Carolina 29634 , United States
| | - Isabell Foulger
- Department of Bioengineering , Clemson University , Clemson , South Carolina 29634 , United States
| | - Joseph W Kolis
- Department of Chemistry , Clemson University , Clemson , South Carolina 29634 , United States
| | - Kelli E Cannon
- Department of Vision Science , University of Alabama at Birmingham , Birmingham , Alabama 35294 , United States
| | - Aundrea F Bartley
- Department of Neurobiology, Evelyn F. McKnight Brain Institute & Civitan International Research Center , University of Alabama at Birmingham , Birmingham , Alabama 35294 , United States
| | - Lynn E Dobrunz
- Department of Neurobiology, Evelyn F. McKnight Brain Institute & Civitan International Research Center , University of Alabama at Birmingham , Birmingham , Alabama 35294 , United States
| | - Mark S Bolding
- Department of Radiology , University of Alabama at Birmingham , Birmingham , Alabama 35294 , United States
| | - Lori McMahon
- Department of Cell, Developmental, and Integrative Biology , University of Alabama at Birmingham , Birmingham , Alabama 35294 , United States
| | - Stephen H Foulger
- Center for Optical Materials Science and Engineering Technologies , Clemson University , Anderson , South Carolina 29625 , United States
- Department of Bioengineering , Clemson University , Clemson , South Carolina 29634 , United States
- Department of Materials Science and Engineering , Clemson University , Clemson , South Carolina 29634 , United States
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Huo T, Dong F, Deng J, Zhang Q, Ye W, Zhang W, Wang P, Sun D. In vitro genotoxicity of asbestos substitutes induced by coupled stimulation of dissolved high-valence ions and oxide radicals. Environ Sci Pollut Res Int 2018; 25:22356-22367. [PMID: 28766145 DOI: 10.1007/s11356-017-9796-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Accepted: 07/19/2017] [Indexed: 06/07/2023]
Abstract
The wide use of asbestos and its substitutes has given rise to studies on their possible harmful effects on human health and environment. However, their toxic effects remain unclear. The present study was aimed to disclose the coupled effects of dissolved high-valence ions and oxide radicals using the in vitro cytotoxicity and genotoxicity of chrysotile (CA), nano-SiO2 (NS), ceramic fiber (CF), glass fiber (GF), and rock wool (RW) on Chinese hamster lung cells V79. All samples induced cell mortality correlated well with the chemical SiO2 content of asbestos substitutes and the amount of dissolved Si. Alkali or alkaline earth metal elements relieved mortality of V79 cells; Al2O3 reinforced toxicity of materials. Asbestos substitutes generated lasting, increasing amount of acellular ·OH which formed at the fiber surface at sites with loose/unsaturated bonds, as well as by catalytic reaction through dissolved iron. Accumulated mechanical and radical stimulation induced the intracellular reactive oxygen species (ROS) elevation, morphology change, and deviating trans-membrane ion flux. The cellular ROS appeared as NS > GF > CF ≈ CA > RW, consistent with cell mortality rather than with acellular ·OH generation. Chromosomal and DNA lesions in V79 cells were not directly associated with the cellular ROS, while influenced by dissolved high-valence irons in the co-culture medium. In conclusion, ions from short-time dissolution of dust samples and the generation of extracellular ·OH presented combined effects in the elevation of intracellular ROS, which further synergistically induced cytotoxicity and genotoxicity.
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Affiliation(s)
- Tingting Huo
- Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology, Mianyang, 621010, China
- Institute of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Faqin Dong
- Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology, Mianyang, 621010, China.
| | - Jianjun Deng
- Clinical Laboratory, Mianyang 404 Hospital, Mianyang, 621010, China
- School of Public Health, Southwest Medical University, Luzhou, 646000, China
| | - Qingbi Zhang
- School of Public Health, Southwest Medical University, Luzhou, 646000, China
| | - Wei Ye
- School of Public Health, Southwest Medical University, Luzhou, 646000, China
| | - Wei Zhang
- Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology, Mianyang, 621010, China
| | - Pingping Wang
- Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology, Mianyang, 621010, China
| | - Dongping Sun
- Institute of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
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Blinova I, Vija H, Lukjanova A, Muna M, Syvertsen-Wiig G, Kahru A. Assessment of the hazard of nine (doped) lanthanides-based ceramic oxides to four aquatic species. Sci Total Environ 2018; 612:1171-1176. [PMID: 28892861 DOI: 10.1016/j.scitotenv.2017.08.274] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [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: 03/22/2017] [Revised: 06/29/2017] [Accepted: 08/27/2017] [Indexed: 06/07/2023]
Abstract
The risk of environmental pollution with rare earth oxides rises in line with increasing application of these compounds in different sectors. However, data on potential environmental hazard of lanthanides is scarce and concerns mostly Ce and Gd. In this work, the aquatic toxicity of eight doped lanthanide-based ceramic oxides (Ce0.9Gd0.1O2, LaFeO3, Gd0.97CoO3, LaCoO3, (La0.5Sr0.5)0.99MnO3, Ce0.8Pr0.2O2, (La0.6Sr0.4)0.95CoO3, LaNiO4) and one non-doped oxide (CeO2) with primary size from 23 to 590nm were evaluated in four short-term laboratory assays with freshwater crustaceans and duckweeds. Results showed no acute toxicity (EC50>100mg/L) or very low acute toxicity for most studied oxides. Observed toxicity was probably due to bioavailable fraction of dopant metals (Ni and Co) but in the case of aquatic plants, decrease of nutrient availability (complexing of phosphorus by lanthanides) was also presumed. Studied oxides/metals accumulated in the aquatic plant tissue and in the gut of crustaceans and thus may be further transferred via the aquatic food chain. Accumulation of metals in the duckweed Lemna minor may be recommended as a cost-effective screening bioassay for assessment of potential hazard of poorly soluble oxides to aquatic ecosystems.
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Affiliation(s)
- Irina Blinova
- Laboratory of Environmental Toxicology, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618, Estonia.
| | - Heiki Vija
- Laboratory of Environmental Toxicology, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618, Estonia
| | - Aljona Lukjanova
- Laboratory of Environmental Toxicology, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618, Estonia
| | - Marge Muna
- Laboratory of Environmental Toxicology, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618, Estonia; Tallinn University of Technology, Ehitajate tee 5, Tallinn 19086, Estonia
| | | | - Anne Kahru
- Laboratory of Environmental Toxicology, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618, Estonia; Estonian Academy of Sciences, Kohtu 6, Tallinn 10130, Estonia
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Seitoku E, Abe S, Kusaka T, Nakamura M, Inoue S, Yoshida Y, Sano H. Cytocompatibility of HeLa Cells to Nano-Sized Ceramics Particles. J Nanosci Nanotechnol 2016; 16:3373-3377. [PMID: 27451635 DOI: 10.1166/jnn.2016.12309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In this study, we investigated the behaviors and cytocompatibility response of human cervical carcinoma (HeLa) cells expose to nano-sized particles. Cultivated cells exposed to titanium oxide and indium oxide nanoparticles remained highly viable. In the presence of copper oxide (CuO); however, the cells became seriously inflamed. To understand the mechanism by which CuO causes cell death, we evaluated cell death and apoptosis cytometry. CuO induced cells apoptosis more strongly than exposure to titania nanoparticles. Confocal fluorescence microscopy revealed that the nano-sized particles penetrate the cells.
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Wnukiewicz W, Rutowski R, Zboromirska-Wnukiewicz B, Reichert P, Gosk J. Evaluation of Soft Tissue Reaction to Corundum Ceramic Implants Infiltrated with Colloidal Silver. ADV CLIN EXP MED 2016; 25:129-33. [PMID: 26935507 DOI: 10.17219/acem/32629] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BACKGROUND Corundum ceramic is a biomaterial used as a bone graft substitute. Silver is a well known antiseptic substance with many practical, clinical applications. OBJECTIVES The aim of this study was to estimate soft tissue (in vivo) reaction to a new kind of ceramic implants. In our experiment, we examined the soft tissue reaction after implantation of corundum ceramic infiltrated with colloidal silver in the back muscles of 18 Wistar rats. The use of colloidal silver as a coating for the implant was designed to protect it against colonization by bacteria and the formation of bacterial biofilm. MATERIAL AND METHODS In our study, based on the experimental method, we performed implantation operations on 18 Wistar rats. We implanted 18 modified ceramic implants and, as a control group, 18 unmodified implants. As a follow up, we observed the animals operated upon, and did postoperative, autopsy and histopathological examinations 14, 30, 90 and 180 days after implantation. RESULTS We didn't observe any pathological reactions and significant differences between the soft tissue reaction to the modified implants and the control group. CONCLUSIONS Lack of pathological reaction to the modified implants in the living organism is the proof of their biocompatibility. This is, of course, the first step on the long path to introduce a new kind of biocompatible ceramic implant with antiseptic cottage. Our experiment has an only introductory character and we plan to perform other, more specific, tests of this new kind of implant.
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Affiliation(s)
- Witold Wnukiewicz
- Department of Traumatology, Clinic of Traumatology and Hand Surgery, Wroclaw Medical University, Poland
| | - Roman Rutowski
- Department of Sport Medicine, The University School of Physical Education, Wrocław, Poland
| | | | - Paweł Reichert
- Department of Traumatology, Clinic of Traumatology and Hand Surgery, Wroclaw Medical University, Poland
| | - Jerzy Gosk
- Department of Traumatology, Clinic of Traumatology and Hand Surgery, Wroclaw Medical University, Poland
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Díaz-Rodríguez P, González P, Serra J, Landin M. Key parameters in blood-surface interactions of 3D bioinspired ceramic materials. Mater Sci Eng C Mater Biol Appl 2014; 41:232-9. [PMID: 24907756 DOI: 10.1016/j.msec.2014.04.058] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [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: 12/13/2013] [Revised: 03/26/2014] [Accepted: 04/22/2014] [Indexed: 11/18/2022]
Abstract
Direct contact of materials with blood components may trigger numerous processes which ultimately lead to hemolysis, clot formation and recruitment of inflammatory cells. In this study, the blood-surface interactions for two inert bioinspired ceramic scaffolds obtained from natural resources; biomorphic carbon and silicon carbides (bioSiC) from different origins have been studied. The response of the blood in contact with carbon is well known, however little has been identified on the influence of their 3D porous structure. Moreover, to our knowledge, there is no reference in the literature about the hemocompatibility of biomorphic silicon carbide as a porous scaffold. The experimental results showed the surface energy to be crucial to evaluate the hemocompatibility of a material however the surface topography and material porosity are also parameters to be considered. Surface roughness modifies clot formation whereas for protein adsorption total sample porosity seems to be the key parameter to be considered for hydrophilic materials (biomorphic silicon carbides), while the size of the pores determines the hemolytic response.
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Affiliation(s)
- P Díaz-Rodríguez
- Dpto. Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Santiago de Compostela, Santiago de Compostela, 15782 Spain
| | - P González
- Dpto. Física Aplicada, E.E. Industriais, Universidade de Vigo, Vigo, Spain
| | - J Serra
- Dpto. Física Aplicada, E.E. Industriais, Universidade de Vigo, Vigo, Spain
| | - M Landin
- Dpto. Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Santiago de Compostela, Santiago de Compostela, 15782 Spain.
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Fongmoon D, Pongnikorn S, Chaisena A, Iamsaard S. Particulate matters collected from ceramic factories in Lampang Province affecting rat lungs. J Zhejiang Univ Sci B 2014; 15:75-83. [PMID: 24390747 PMCID: PMC3891121 DOI: 10.1631/jzus.b1300058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 07/12/2013] [Indexed: 01/09/2023]
Abstract
BACKGROUND Lung cancer ranks as the fifth largest of all cancer cases in Thailand. However, it is the first leading cancer in the northern part of Thailand (data from 2003-2007). There are several predisposing causes that lead to lung cancer and one important inducement is particulate matters (PMs). Lampang Province in Thailand is famous for the ceramic industry, where there are over 200 ceramic industrial factories. PMs are produced during the ceramic manufacturing process and spread throughout all of the working areas. It is very possible that workers could directly inhale PM-contaminated air during working hours. OBJECTIVE This study focuses on the toxic effects of PMs collected from ceramic factories on genes and lungs of rats. METHODS PMs collected from six ceramic factories in Lampang Province were extracted using dimethyl sulfoxide (DMSO). The inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES) were used to analyze the chemical elements at lower and higher concentrations, respectively. Then, the toxicity of PMs on the genes was examined by the Ames test, and subsequently, the effect of PMs on DNA was examined by quantifying the amount of 8-hydroxy-2'-deoxyguanosine (8-OHdG). Finally, the toxicity of the PMs on rat's lungs was examined by histology. RESULTS As chemical elements of lower concentrations, cadmium, chromium, nickel, copper, and lead were detected by ICP-MS. As chemical elements of higher concentrations, manganese, magnesium, zinc, iron, potassium, calcium, and sodium were detected by ICP-OES. No mutagenicity in Salmonella typhimurium was found in the PM extracts from all six factories by utilizing the Ames test. In the histological study, the reduction in spaces of alveolar ducts and sacs, and terminal bronchioles, the thickening of interstitial connective tissues were noted by PM extracts in high amounts (100 and 350 µg). Female rats were more sensitive to PM extracts than males in terms of their pulmonary damages. CONCLUSIONS PMs were not mutagenic to S. typhimurium but can damage the lung tissue of rats.
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Affiliation(s)
- Duriya Fongmoon
- Department of Medical Services, Lampang Cancer Hospital, Ministry of Public Health, Lampang 52000, Thailand
| | - Surathat Pongnikorn
- Department of Medical Services, Lampang Cancer Hospital, Ministry of Public Health, Lampang 52000, Thailand
| | - Aphiruk Chaisena
- Department of Applied Chemistry and Centre for Innovation in Chemistry, Faculty of Science, Lampang Rajabhat University, Lampang 52100, Thailand
| | - Sitthichai Iamsaard
- Department of Anatomy and Integrative Complementary Alternative Medicine (ICAM) Research and Development Group, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
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14
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Zhang M, Zhu LJ, Xiao Y, Zhang X. [Effects of p38 mitogen-activated protein kinases on the apoptosis of human bronchial epithelial cells induced by refractory ceramic fibers in vitro]. Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi 2013; 31:347-350. [PMID: 23803523] [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] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
OBJECTIVE To investigate the role of p38 mitogen-activated protein kinases (MAPKs) in the apoptosis of human bronchial epithelial cells (BEAS-2B) induced by refractory ceramic fibers (RCFs). METHODS BEAS-2B cells were exposed to 10, 20, 40, 80, and 160 µg/cm(2) RCF1, RCF2, and RCF3 for 24 h, and the cell viability was measured by CCK-8 assay. BEAS-2B cells were exposed to 20, 40, and 100 µg/cm(2) RCF1, RCF2, and RCF3 for 24 h, and the cell apoptosis rate was measured by flow cytometry. BEAS-2B cells were exposed to 40 µg/cm(2) RCF1, RCF2, and RCF3, and the expression levels of phospho-p38 MAPK and caspase-3 were measured by Western blot. In each of the above treatments, the BEAS-2B cells were divided into positive control, p38 inhibitor SB203580 intervention, and normal groups. RESULTS As the concentration of RCFs rose, the RCF exposure groups showed decreased cell viability and increased cell apoptosis rate. After SB203580 intervention, the intervention groups (all concentrations of asbestos + SB, 20, 40, 80, and 160 µg/cm(2)RCF1+SB, and 40, 80, and 160 µg/cm(2) RCF2 and RCF3+SB) had significantly increased cell viabilities (P < 0.05), and the intervention groups (asbestos + SB and 20, 40, and 100 µg/cm(2) RCF1, RCF2, and RCF3 + SB) had significantly decreased cell apoptosis rates (P < 0.05). Compared with the normal group, the RCF (40 µg/cm(2)) exposure and positive control groups had significantly increased expression of phospho-p38 MAPK (P < 0.05), and the RCF (40 µg/cm(2)) exposure group had significantly increased expression of caspase-3 (P < 0.05). The intervention groups (asbestos + SB and 40 µg/cm(2) RCF1, RCF2, and RCF3 + SB) had significantly decreased expression of caspase-3 after SB203580 intervention. CONCLUSION p38 MAPKs play an important role in RCF-induced apoptosis of BEAS-2B cells.
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Affiliation(s)
- Min Zhang
- Institute of Hygiene, Zhejiang Academy of Medical Sciences, Hangzhou 310013, China
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Godinho-Castro AP, Testolin RC, Janke L, Corrêa AXR, Radetski CM. Incorporation of gypsum waste in ceramic block production: Proposal for a minimal battery of tests to evaluate technical and environmental viability of this recycling process. Waste Manag 2012; 32:153-157. [PMID: 21959139 DOI: 10.1016/j.wasman.2011.08.019] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 08/10/2011] [Accepted: 08/29/2011] [Indexed: 05/31/2023]
Abstract
Civil engineering-related construction and demolition debris is an important source of waste disposed of in municipal solid waste landfills. After clay materials, gypsum waste is the second largest contributor to the residential construction waste stream. As demand for sustainable building practices grows, interest in recovering gypsum waste from construction and demolition debris is increasing, but there is a lack of standardized tests to evaluate the technical and environmental viability of this solid waste recycling process. By recycling gypsum waste, natural deposits of gypsum might be conserved and high amounts of the waste by-product could be reused in the civil construction industry. In this context, this paper investigates a physical property (i.e., resistance to axial compression), the chemical composition and the ecotoxicological potential of ceramic blocks constructed with different proportions of clay, cement and gypsum waste, and assesses the feasibility of using a minimal battery of tests to evaluate the viability of this recycling process. Consideration of the results for the resistance to axial compression tests together with production costs revealed that the best formulation was 35% of plastic clay, 35% of non-plastic clay, 10% of Portland cement and 20% of gypsum waste, which showed a mean resistance of 4.64MPa. Energy dispersive X-ray spectrometry showed calcium and sulfur to be the main elements, while quartz, gypsum, ettringite and nacrite were the main crystalline compounds found in this formulation. Ecotoxicity tests showed that leachate from this formulation is weakly toxic toward daphnids and bacteria (EC(20%)=69.0 and 75.0, respectively), while for algae and fish the leachate samples were not toxic at the EC(50%) level. Overall, these results show that the addition of 20% of gypsum waste to the ceramic blocks could provide a viable substitute for clay in the ceramics industry and the tests applied in this study proved to be a useful tool for the technical and environmental evaluation of this recycling process, bacterial and daphnid tests being more sensitive than algae and fish tests.
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Haiying Z, Youcai Z, Jingyu Q. Utilization of municipal solid waste incineration (MSWI) fly ash in ceramic brick: product characterization and environmental toxicity. Waste Manag 2011; 31:331-341. [PMID: 21067908 DOI: 10.1016/j.wasman.2010.10.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Revised: 09/14/2010] [Accepted: 10/20/2010] [Indexed: 05/30/2023]
Abstract
In this study, municipal solid waste incineration (MSWI) fly ash was used as a blending in making ceramic brick based on its characterization and an orthogonal test was performed to determine the optimal mixture ratio of the materials. Besides, the fired bricks made in accordance with the optimal mixture ratio were characterized for performance, phase transformation, microstructure, leaching toxicity of the heavy metals in accordance with GB/T 2542-92 (Detection methods for bricks analysis, China) and by means of XRD, SEM and leaching toxicity analysis. It was found that the optimal mixture ratio of materials (MSWI fly ash:red ceramic clay:feldspar:gang sand) was 20:60:10:10 by mass, and the optimal sintering temperature was 950°C. Leaching results of heavy metals from sintered bricks were reduced considerably in comparison with those from green bricks prior to sintering process. The results as a whole suggested that utilization of MSWI fly ash in ceramic brick constituted a potential means of adding value.
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Affiliation(s)
- Zhang Haiying
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai, China.
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17
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Yong Z, Ji-ying W. [Study on the cytotoxicity induced by ceramic alloys]. Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi 2010; 26:929-930. [PMID: 21140979] [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: 05/30/2023]
Abstract
AIM To investigate the cytotoxicity of 3 kinds of dental ceramic alloys. METHODS Methods of 4-methyl-thiazolyl tetrazolium assay (MTT) and single cell gel electrophoresis (comet assay) were used to detect the influence on mouse fibroblast L929 relative growth rate (relative growth rate, RGR) and damage of DNA induced by three kinds of ceramic alloys. RESULTS RGR of the golden alloy group was 87.7 ± 11.3 which showed no significant difference when compared with the cobalt-chromium alloy group and the control group, while among other groups, there were statistically significant differences in RGR (P<0.05); the rank of DNA damage of nickel-chromium alloy was severe, while the ranks of cobalt-chromium alloy and golden alloy group were moderate and mild respectively. CONCLUSION The influence of golden alloy and cobalt-chromium alloy on RGR is significantly lower than nickel-chromium alloy, meanwhile the damage of DNA caused by golden alloy is lightest, so it is a kind of dental ceramic alloy with good biocompatibility.
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Affiliation(s)
- Zhang Yong
- Department of Prosthodontics, Affiliated Dental Hospital, Zunyi Medical College, Zunyi, China.
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Vitral JCDA, Fraga MR, de Souza MA, Ferreira AP, Vitral RWF. In-vitro study of cellular viability and nitric oxide production by J774 macrophages stimulated by interferon gamma with ceramic, polycarbonate, and polyoxymethylene brackets. Am J Orthod Dentofacial Orthop 2010; 137:665-70. [PMID: 20451786 DOI: 10.1016/j.ajodo.2008.07.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [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: 05/01/2008] [Revised: 06/01/2008] [Accepted: 07/01/2008] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Ceramic brackets are chemically inert in the oral cavity, whereas polycarbonate and polyoxymethylene brackets can degrade and release bisphenol-A and formaldehyde, respectively. More reliable tests are needed to assess the potential toxicity of these materials. In addition to traditional cytotoxicity tests, the study of nitric oxide (NO) cellular production stimulated by a specific material has been shown to be a reliable tool for evaluating cytotoxic potential. The purpose of this study was to assess, with esthetic brackets, cellular viability by 3,(4,5-dimethylthiazol-2-yl)-2,5diphenyltetrazolium bromide assay (Sigma, St. Louis, Mo) in the macrophage cell line J774 stimulated with interferon gamma. Interferon gamma is a key cytokine in the activation of macrophages, plays an important role in immunologic processes, and also quantifies NO production by these macrophages. METHODS Well plates were seeded with 2 x 104 J774 cells per well, in a volume of 100 microL, resuspended in Roswell Park Memorial Institute Supplemented Medium 1640. The macrophage cell line J774 was stimulated with interferon gamma. Ceramic, polycarbonate, and polyoxymethylene brackets were added and kept in the culture for 24, 48, or 72 hours in 5% carbon dioxide at 37 degrees C; the control samples did not include brackets. At the end of each incubation period, the supernatant was collected for posterior NO quantification, and the cells were evaluated for cytotoxicity. RESULTS Cellular viability in all groups was higher at 72 hours than at 24 hours. The final means in the bracket groups did not show significant differences compared with the control group. NO production was significantly greater in all groups at the final time than at the initial time. However, the brackets with the interferon gamma stimulation did not result in greater NO production than did the cells in the control group.
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Zoitos BK, Andrejcak MJ, Boymel PM, Maxim LD, Niebo R. Horizontal Diffusion Elutriation: A New Size-Separation Technique for Preparation of Rodent-Respirable Fibers for Animal Testing. Inhal Toxicol 2010; 19:37-46. [PMID: 17127641 DOI: 10.1080/08958370600985800] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Short-and long-term animal experiments are used to examine the toxicology and biopersistence of various types of fibers. In order to ensure an adequate exposure dose for testing, modern experimental protocols specify that the exposure aerosol (in an inhalation test) or the fibers (in an intratracheal instillation [IT] test) must contain at least a minimum concentration of long (> 20 mum) rodent-respirable fibers. As produced and handled, most fibers contain a distribution of diameters and lengths, only some of which are both long and rodent-respirable. Therefore, it is necessary to size-separate the fibers to enrich the proportion of long, rodent-respirable fibers in the material to be tested. This article presents a new and relatively simple method for size separation that avoids some of the difficulties associated with other methods. The method, termed horizontal diffusion elutriation (HDE), is illustrated by size-separating refractory ceramic fiber (RCF) and four polycrystalline alumina (PCA) fibers.
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Affiliation(s)
- Bruce K Zoitos
- Unifrax Corporation, Niagara Falls, New York 4305-2413, USA
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Abstract
In 1999 Berry published a model for mesothelioma incidence following fiber exposure. He concluded, that the influence of the solubility of fibers on the mesothelioma rate is 17 times higher in humans than in rats. This conclusion may be helpful for evaluating the carcinogenic risk from man-made vitreous fibers, but it had little influence on some recent discussions. It has been demonstrated using this model, that in an injection experiment with rats, fibers with elimination constants of 0.1/year and 1/year--which would approximately correspond to crocidolite and perhaps ceramic fibers--differ in their mesothelioma risk only by a ratio of 3.2:1. In contrast, for humans exposed continuously from age 20 to age 60 a risk ratio of 4,750:1 is obtained. This result may be helpful for the assessment of the human cancer risk e.g., from exposure to refractory ceramic fibers. However, uncertainty is large, since the life-span of rats is too low to measure the elimination rate of bio-persistent fibers sufficiently.
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Affiliation(s)
- Klaus Rödelsperger
- Institut und Poliklinik für Arbeits- und Sozialmedizin der Justus Liebig Universität Giessen, Giessen, Germany.
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Fan C, Liu D, Ren Y. [Preparation of chitosan-encapsulated porous calcium polyphosphate bioceramic]. Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi 2007; 21:1355-1358. [PMID: 18277683] [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] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
OBJECTIVE To investigate the preparation of a chitosan-encapsulated porus calcium polyphosphate (CPP) bioceramic so as to provide a feasible approach to repair of the bone defect. METHODS The chitosan microspheres were produced by chemical procedures. The CPP bioceramic was made by the following steps: annealing, ball milling, admixing, and calcinating. The chemical method was used to encapsule the calcinated bioceramic by the porus chitosan film. The physicochemical property, biomechanical property, and toxicity of the chitosan-encapsulated porus CPP bioceramic were analyzed. RESULTS The uniform holes were observed in the CPP bioceramic under a microscope. The diameter of the hole was 100-300 microm. The chitosan microballoons were amber in color. The particles were uniform with a diameter of 200-400 microm, with a poor compressive strength. They could be easily ground by hand. The maximally tolerated dose of the CPP bioceramic leaching liquor given to the Jimpy mice of both sexes was >24 g/kg on average. The compressive strength reached 200 MPa, and the interval porosity was about 60%-80%, which could completely meet with the compressive strength of the bone substitute. CONCLUSION The chitosan-encapsulated porous CPP bioceramic can be used as a good porous bioceramic scaffold material, which has a good biomechanical property with no acute toxicity, and so may be used as an excellent material for the bone substitute.
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Affiliation(s)
- Changchun Fan
- Department of Traumatic Orthopedics, the Second Military Medical University Jinan school of Medicine, Jinan Shandong, 250031, PR China.
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Carel R, Olsson AC, Zaridze D, Szeszenia-Dabrowska N, Rudnai P, Lissowska J, Fabianova E, Cassidy A, Mates D, Bencko V, Foretova L, Janout V, Fevotte J, Fletcher T, 't Mannetje A, Brennan P, Boffetta P. Occupational exposure to asbestos and man-made vitreous fibres and risk of lung cancer: a multicentre case-control study in Europe. Occup Environ Med 2007; 64:502-8. [PMID: 17053017 PMCID: PMC2078502 DOI: 10.1136/oem.2006.027748] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/06/2006] [Indexed: 11/03/2022]
Abstract
OBJECTIVES To investigate the contribution of occupational exposure to asbestos and man-made vitreous fibres (MMVF) to lung cancer in high-risk populations in Europe. METHODS A multicentre case-control study was conducted in six Central and Eastern European countries and the UK, during the period 1998-2002. Comprehensive occupational and sociodemographic information was collected from 2205 newly diagnosed male lung cancer cases and 2305 frequency matched controls. Odds ratios (OR) of lung cancer were calculated after adjusting for other relevant occupational exposures and tobacco smoking. RESULTS The OR for asbestos exposure was 0.92 (95% CI 0.73 to 1.15) in Central and Eastern Europe and 1.85 (95% CI 1.07 to 3.21) in the UK. Similar ORs were found for exposure to amphibole asbestos. The OR for MMVF exposure was 1.23 (95% CI 0.88 to 1.71) with no evidence of heterogeneity by country. No synergistic effect either between asbestos and MMVF or between any of them and smoking was found. CONCLUSION In this large community-based study occupational exposure to asbestos and MMVF does not appear to contribute to the lung cancer burden in men in Central and Eastern Europe. In contrast, in the UK the authors found an increased risk of lung cancer following exposure to asbestos. Differences in fibre type and circumstances of exposure may explain these results.
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Affiliation(s)
- Rafael Carel
- International Agency for Research on Cancer, Lyon, France
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Linnainmaa M, Kangas J, Mäkinen M, Metsärinne S, Tossavainen A, Säntti J, Veteli M, Savolainen H, Kalliokoski P. Exposure to Refractory Ceramic Fibres in the Metal Industry. ACTA ACUST UNITED AC 2007; 51:509-16. [PMID: 17607019 DOI: 10.1093/annhyg/mem027] [Citation(s) in RCA: 4] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Refractory ceramic fibres (RCF) are used in thermal isolation in the metal industry where high temperatures are regularly employed. Asbestos materials were earlier commonly used for these purposes. In this work, two Finnish steel plants, three foundries and a repair shop were studied for the ceramic fibre exposure of their workers under normal production and during the replacement of oven insulation. Personal and stationary sampling was used together with a novel nasal lavage sampling for the evaluation of personal exposure. Fibres were counted with optical and electron microscopy and they were identified using an energy-dispersive X-ray analyser. Ceramic fibres were found in most production phases [range <0.01-0.29 fibres per cubic centimetre (f cm(-3))]. Considerably higher fibre counts were obtained during the maintenance work (range <0.01-14.2 f cm(-3)). Nasal sampling was found to correlate with the airborne fibre concentrations at the group level. The mean fibre concentrations varied from 34 to 6680 f ml(-1) of lavage liquid. Use of personal respiratory protectors diminished the exposure on the average as analysed in the lavage specimens, but the effect of respirator use did not appear clearly in the results. Because of the heat conditions, the workers used the respirators for a strict minimum period. A considerable exposure to RCF occurs in the studied plants. Its risk should be evaluated and managed more closely in view that the material is carcinogenic. Use of personal respiratory protectors should be encouraged. Their effective use could be verified by the nasal sampling for fibres after the work shift.
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Affiliation(s)
- Markku Linnainmaa
- Finnish Institute of Occupational Health, P.O. Box 93, FI-70701 Kuopio, Finland.
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Andujar P, Lecomte C, Renier A, Fleury-Feith J, Kheuang L, Daubriac J, Janin A, Jaurand MC. Clinico-pathological features and somatic gene alterations in refractory ceramic fibre-induced murine mesothelioma reveal mineral fibre-induced mesothelioma identities. Carcinogenesis 2007; 28:1599-605. [PMID: 17272307 PMCID: PMC4749665 DOI: 10.1093/carcin/bgm023] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Although human malignant mesothelioma (HMM) is mainly caused by asbestos exposure, refractory ceramic fibres (RCFs) have been classified as possibly carcinogenic to humans on the basis of their biological effects in rodents' lung and pleura and in cultured cells. Hence, further investigations are needed to clarify the mechanism of fibre-induced carcinogenicity and to prevent use of harmful particles. In a previous study, mesotheliomas were found in hemizygous Nf2 (Nf2(+/-)) mice exposed to asbestos fibres, and showed similar alterations in genes at the Ink4 locus and in Trp53 as described in HMM. Here we found that Nf2(+/-) mice developed mesotheliomas after intra-peritoneal inoculation of a RCF sample (RCF1). Clinical features in exposed mice were similar to those observed in HMM, showing association between ascite and mesothelioma. Early passages of 12 mesothelioma cell cultures from ascites developed in RCF1-exposed Nf2(+/-) mice demonstrated frequent inactivation by deletion of genes at the Ink4 locus, and low rate of Trp53 point and insertion mutations. Nf2 gene was inactivated in all cultures. In most cases, co-inactivation of genes at the Ink4 locus and Nf2 was found and, at a lower rate, of Trp53 and Nf2. These results are the first to identify mutations in RCF-induced mesothelioma. They suggest that nf2 mutation is complementary of p15(Ink4b), p16(Ink4a) and p19(Arf) or p53 mutations and show similar profile of gene alterations resulting from exposure to ceramic or asbestos fibres in Nf2(+/-) mice, also consistent with the one found in HMM. These somatic genetic changes define different pathways of mesothelial cell transformation.
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Kováciková Z, Hurbánková M, Cerná S, Tátrai E, Beno M, Wimmerová S. Effect of exposure to ceramic fibres and cigarette smoke on antioxidant status of the lung. Neuro Endocrinol Lett 2006; 27 Suppl 2:23-6. [PMID: 17159772] [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] [Subscribe] [Scholar Register] [Received: 09/12/2006] [Accepted: 10/24/2006] [Indexed: 05/12/2023]
Abstract
OBJECTIVES The programmes of asbestos replacement brought the need to use other fibres for insulation or reinforcement of material. The aim of the presented study was to follow the effect of refractory ceramic fibres (RCF3) alone or in combination with cigarette smoke (CS) on antioxidant status of the lung in experiment on animals. As free radicals are supposed to play a role in pathogenesis of lung diseases and the toxicity of particles has been associated with production of reactive oxygen species, the antioxidant status may serve as marker of lung injury. Our hypothesis was that the effect of combined exposure to RCF3 and CS will be additive or synergic. DESIGN Scheme of experiment: Wistar rats were randomly divided into 4 groups per 6 animals: control, intratracheal exposure to 4 mg of RCF3, inhalatory exposure to mainstream of cigarette smoke from 8 standard research 1R1 cigarettes per day, and both intratracheal exposure to RCF3 and inhalatory to CS. The exposure lasted 6 months, the inhalatory exposure was performed 5 times per week. After finishing the exposure bronchoalveolar lavage of lungs was performed and ascorbic acid, superoxide dismutase, glutathione and glutathione peroxidase were determined in lung tissue and cell free fraction of bronchoalveolar lavage fluid (BALF). RESULTS The results showed that the most sensitive indicator of changes in antioxidant status was glutathione, which was changed in all groups both in BALF and lung tissue homogenate.
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Affiliation(s)
- Zuzana Kováciková
- Research Base of the Slovak Medical University, Bratislava, Slovakia.
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Tátrai E, Kováciková Z, Brózik M, Six E, Csík M, Tulinska J, Drahos A, Dám A. The influence of refractory ceramic fibres on pulmonary morphology, redox and immune system in rats. J Appl Toxicol 2006; 26:500-8. [PMID: 17086511 DOI: 10.1002/jat.1169] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Refractory ceramic fibres (RCF) were studied in male SPRD rats by both in vivo long term sequential and in vitro methods. RCF was administered by single intratracheal instillation and the lungs were examined at the end of months 1, 3 and 6 after exposure. In addition, the direct toxicity of the fibres was examined in a primary culture of alveolar macrophages (AM) and in pneumocytes type II (T2). Pulmonary morphological changes, a number of parameters of the redox system, such as activity of extracellular Cu,Zn/superoxide dismutase (EC-SOD), total glutathione content of the lungs (GSH) and immunoglobulins in bronchoalveolar lavage (IgA, IgG, IgM) and in the blood were measured. The composition of the original RCF and the elemental content of the lung tissue were compared by energy dispersive x-ray analysis (EDXA) before and after exposure. Macrophage alveolitis became confluent and moderate fibrosis developed by the end of month 3, and after 6 months of exposure the intensity decreased to the level of the first month. The RCF did not significantly influence the activity of EC-SOD or the total glutathione content of the lungs. Although aluminium and silicon could be demonstrated by EDXA in the lung tissue at the end of month 3, these elements were no longer detectable by the end of month 6. The RCF decreased IgA significantly in bronchoalveolar lavage (BAL). The main components of RCF induced pulmonary alterations, whereas no significant change could be detected in EC-SOD and GSH. Injuries caused by direct toxicity could be observed in the cell membranes only at the highest concentration. On the basis of these results RCF can be determined as moderately toxic fibres.
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Affiliation(s)
- Erzsébet Tátrai
- National Institute of Environmental Health, Budapest PO Box 22, H-1450 Hungary.
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Quan R, Yang D, Miao X, Wu X, Wang H, Li W. Preparation of Graded Zirconia—Hydroxyapatite Composite Bioceramic and Its Immunocompatibility in vitro. J Biomater Appl 2006; 22:123-44. [PMID: 17065164 DOI: 10.1177/0885328206071454] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
To obtain immunocompatibility, graded zirconia—hydroxyapatite (ZrO 2-HA) composite bioceramic and simplex ZrO2-HA composite bioceramic are prepared. Peripheral blood mononuclear cells (PBMCs) harvested from healthy individuals are cultured with the two ceramic extracts to assess their effect on the transformation of lymphocytes, apoptotic ratio, CD69 expression, and expression of cytokine of TNFα and IL-6, with or without phytohemoagglutinin (PHA)-stimulated cells. Ceramic extracts did not activate the resting lymphocytes, whereas the response of the PHA-stimulated cells was significantly modified. The PBMCs activated by graded ZrO2-HA composite bioceramic is noticeably smaller than that by simplex ZrO2-HA composite bioceramic; these results, however can only be seen under the amplified effect of PHA-stimulation.
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Affiliation(s)
- Renfu Quan
- Department of Orthopaedics, Second Affiliated Hospital, Zhejiang University, 310009 Hangzhou, China
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Abstract
OBJECTIVES To identify and describe the exposure to selected known and suspected carcinogenic agents, mixtures and exposure circumstances for defined job categories in Norway's offshore petroleum industry from 1970 to 2005, in order to provide exposure information for a planned cohort study on cancer. METHODS Background information on possible exposure was obtained through company visits, including interviewing key personnel (n = 83) and collecting monitoring reports (n = 118) and other relevant documents (n = 329). On the basis of a previous questionnaire administered to present and former offshore employees in 1998, 27 job categories were defined. RESULTS This study indicated possible exposure to 18 known and suspected carcinogenic agents, mixtures or exposure circumstances. Monitoring reports were obtained on seven agents (benzene, mineral oil mist and vapour, respirable and total dust, asbestos fibres, refractory ceramic fibres, formaldehyde and tetrachloroethylene). The mean exposure level of 367 personal samples of benzene was 0.037 ppm (range: less than the limit of detection to 2.6 ppm). Asbestos fibres were detected (0.03 fibres/cm3) when asbestos-containing brake bands were used in drilling draw work in 1988. Personal samples of formaldehyde in the process area ranged from 0.06 to 0.29 mg/m3. Descriptions of products containing known and suspected carcinogens, exposure sources and processes were extracted from the collected documentation and the interviews of key personnel. CONCLUSIONS This study described exposure to 18 known and suspected carcinogenic agents, mixtures and exposure circumstances for 27 job categories in Norway's offshore petroleum industry. For a planned cohort study on cancer, quantitative estimates of exposure to benzene, and mineral oil mist and vapour might be developed. For the other agents, information in the present study can be used for further assessment of exposure, for instance, by expert judgement. More systematic exposure surveillance is needed in this industry. For future studies, new monitoring programmes need to be implemented.
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Affiliation(s)
- Kjersti Steinsvåg
- Department of Public Health and Primary Health Care, Section for Occupational Medicine, University of Bergen, Bergen, Norway.
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Bakopoulou AA, Triviai IN, Tsiftsoglou AS, Garefis PD. In vitro assessment of cytotoxicity of resin-based dental restorative materials on WEHI 13 var fibroblasts. INT J PROSTHODONT 2006; 19:13-6. [PMID: 16479751] [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: 05/06/2023]
Abstract
PURPOSE The aim of this study was to assess the cytotoxicity of 4 resin composites' eluates on WEHI 13 Var fibroblasts as they aged in a biologic medium. MATERIALS AND METHODS Cytotoxicity was determined by counting the number of viable cells by trypan blue exclusion. Morphologic changes attributable to cytotoxicity were observed by May-Grunwald-Giemsa cytologic staining and microscopic examination. DNA gel electrophoresis was performed to detect possible genotoxicity and DNA damage. RESULTS All resin composite eluates, except that for Targis, caused a pronounced cytotoxicity during the first 72 hours that gradually decreased after 2 weeks of aging. Severe morphologic alterations and pronounced DNA damage were also observed. CONCLUSION These findings indicate that resin-based dental restorative materials release agents cytotoxic and genotoxic to fibroblasts. Cytotoxicity is gradually decreased as the composite resins age in a biologic-relevant medium.
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Affiliation(s)
- Athina A Bakopoulou
- Department of Fixed & Implant Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, Greece.
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Abstract
BACKGROUND Cell culture studies may provide information on the behavior of biomaterials in the intended implant environment. Cell cultures from such an environment could be used for the development of middle ear implants. MATERIAL AND METHODS Secondary bone-like cell cultures derived from human stapes were exposed to different materials [Al(2)O(3) ceramic, glass ceramic (Ceravital), gold and titanium]. Proliferation was studied for up to 40 days. RESULTS The proliferation of cultured stapes bone-like cells did not differ significantly between the four tested biomaterials. The well known cytotoxic effect of copper, which was used as a control, was evident. CONCLUSIONS Four biomaterials [Al(2)O(3) ceramic, glass ceramic (Ceravital), gold and titanium] have similar biocompatibility and no toxicity when tested in human stapes cell cultures. This in vitro model may be of considerable value for the further development of middle ear implants, e.g., when coated with bone morphogenetic proteins.
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Affiliation(s)
- P Dost
- Universitäts-Hals-Nasen-Ohren-Klinik der Universität Duisburg-Essen.
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Pera P, Conserva E, Pin D, Acquaviva A, Riboldi A, Mariottini GL, Pane L. Cytotoxicity in vitro analysis of ceramic materials for ''metal free'' prosthetic substructures. Minerva Stomatol 2005; 54:363-71. [PMID: 16175165] [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] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
AIM The aim of this study was to investigate the in vitro cytotoxicity of 5 ceramic materials for metal-free fixed prosthodontics: In-Ceram, Cergo, IPS Empress II, Cercon ZrO2, Finesse All Ceram compared each other and to commercially pure Titanium (CpTi). METHODS The materials, prepared directly from manufacturers as 10 mm diameter and 3 mm thickness disks, have been tested following the ISO 10993-l guidelines, performing the in vitro cytotoxicity test with the use of mouse's cells, fibroblasts L-929, isolated by muscular tissue and cultured in an appropriate medium. The MTT test has been used to evaluate the cell viability through the succinate dehydrogenase enzyme activity. The originality of this investigation is that all the materials examined have been tested under the same conditions: the cytotoxicity test has been performed on these materials at the same time, in the same period, under the same conditions of temperature and humidity and by the same operator. RESULTS Not all tested materials were free from cytotoxicity. Cercon, within the limits of this in vitro study, showed the lower cytotoxicity. CONCLUSIONS This in vitro study suggested that ceramic materials for metal free prosthetic substructures are in competition with the CpTi which is very used in implant prosthodontics.
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Affiliation(s)
- P Pera
- Prosthodontics Unit, School of Dentistry, University of Genoa, Genoa, Italy
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Neumann A, Jahnke K, Maier HR, Ragoss C. [Biocompatibilty of silicon nitride ceramic in vitro. A comparative fluorescence-microscopic and scanning electron-microscopic study]. Laryngorhinootologie 2005; 83:845-51. [PMID: 15611905 DOI: 10.1055/s-2004-825739] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND With regard to its favorable physical properties, silicon nitride ceramic is considered as biomaterial for human medical application. Minor controversy exists about the biocompatibility of the material. METHODS Cytotoxicity testing, cell viability and morphology assessment was performed applying the L929-mice fibroblast cell culture model in a direct contact assay. Testing materials were silicon nitride ceramics of different surface properties and titanium alloy as a reference. Polyvinylchloride served as a negative control. The cells were stained with bisbenzimide and propidium iodine for double fluorochromasia viability testing, and evaluated by inversion-fluorescence microscopy. Scanning electron microscopy was applied to additionally investigate cell morphology. RESULTS No cytotoxic effects were observed on the silicon nitride ceramic samples; moreover cell morphology remained the same as on titanium. Avital cells were present exclusively on PVC. The cell growth in the silicon nitride samples showed no significant differences compared to titanium. Cell counts on all polished surfaces showed significantly higher numbers. Scanning electron microscopy revealed typical fibroblast morphology with filiform extensions. CONCLUSION The current results indicate a favorable biocompatibility of silicon nitride ceramic. Cell growth, viability and morphology are comparable to parameters of titanium. Polished surfaces appear to promote cell growth. Further in vivo studies are mandatory prior to human medical application. Owing to its favorable physiochemical properties, especially its superior resistance to mechanical stress, silicon nitride could serve as a biomaterial for osteosynthesis of bone with mucosal attachment.
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Affiliation(s)
- A Neumann
- Universitäts-Hals-Nasen-Ohrenklinik, Essen.
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Denry IL, Holloway JA, Nakkula RJ, Walters JD. Effect of niobium content on the microstructure and thermal properties of fluorapatite glass-ceramics. J Biomed Mater Res B Appl Biomater 2005; 75:18-24. [PMID: 16025471 DOI: 10.1002/jbm.b.30295] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Niobium oxide has been shown to improve biocompatibility and promote bioactivity. The purpose of this study was to evaluate the effect of niobium oxide additions on the microstructure and thermal properties of fluorapatite glass-ceramics for biomedical applications. Four glass-ceramic compositions with increasing amounts of niobium oxide from 0 to 5 wt % were prepared. The glass compositions were melted at 1,525 degrees C for 3 h, quenched, ground, melted again at 1,525 degrees C for 3 h and furnace cooled. The coefficient of thermal expansion was measured by dilatometry. The crystallization behavior was evaluated by differential thermal analysis. The nature of the crystalline phases was investigated by X-ray diffraction. The microstructure was studied by SEM. In addition, the cytotoxicity of the ceramics was evaluated according to the ASTM standard F895--84. The results from X-ray diffraction analyses showed that fluorapatite was the major crystalline phase in all glass-ceramics. Differential thermal analyses revealed that fluorapatite crystallization occurred between 800 and 934 degrees C depending on the composition. The coefficient of thermal expansion varied from 7.6 to 9.4 x 10(-6)/ degrees C. The microstructure after heat treatment at 975 degrees C for 30 min consisted of submicroscopic fluorapatite crystals (200--300 nm) for all niobium-containing glass-ceramics, whereas the niobium-free glass-ceramic contained needle-shaped fluorapatite crystals, 2 microm in length. None of the glass-ceramics tested exhibited any cytotoxic activity as tested by ASTM standard F895--84.
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Affiliation(s)
- I L Denry
- Section of Restorative Dentistry and Prosthodontics, College of Dentistry, The Ohio State University, Columbus, Ohio 43218, USA.
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Abstract
OBJECTIVE To describe the results of combined exchange transfusion and chelation therapy in a neonate with an elevated blood lead level (BLL). CASE SUMMARY A 34-year-old Latina woman with a long history of pica (eating glazed pottery) gave birth to a healthy-appearing girl at 40 weeks of gestation. The mother's preconception BLL was 117 μg/dL and remained elevated throughout pregnancy. At parturition, the mother's BLL was 87 μg/dL and the infant's cord BLL was 100 μg/dL. The infant underwent single-volume exchange transfusion within 12 hours of birth. BLL was 28 μg/dL following the exchange, and a 5-day course of chelation with dimercaprol and CaNa2 ethylenediamine tetraacetic acid was initiated at 36 hours of life. The infant's BLL was 37 μg/dL at the end of inpatient chelation. DISCUSSION Long-term neurologic disability from in utero lead exposure is well described, but the optimal treatment of elevated neonatal BLLs in healthy-appearing infants at the time of birth is not established. This strategy of combined chelation and exchange transfusion therapy was well tolerated and resulted in decreased lead levels, but the long-term neurologic efficacy of our combination strategy remains to be seen. CONCLUSIONS Combined exchange transfusion and chelation therapy resulted in rapidly decreased lead levels in a neonate with chronic in utero lead exposure.
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Affiliation(s)
- Mark B Mycyk
- Division of Emergency Medicine, Northwestern University School of Medicine, Section of Toxicology, Cook County Hospital, Chicago, IL 60611-2930, USA.
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Tysowsky GW. Readers' Round Table. J Prosthet Dent 2004; 91:299; author reply 299-300. [PMID: 15074298 DOI: 10.1016/j.prosdent.2004.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Ceramic fibers (respirable size). Rep Carcinog 2004; 11:III46-7. [PMID: 21089820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
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Abstract
STATEMENT OF PROBLEM The biocompatibility of new dental ceramics has not been assessed with the same scrutiny as has been applied to alloys and composites. Yet, the biocompatibility of ceramics is critical to the long-term success of dental prostheses because ceramics are in close contact with oral tissues for extended periods. MATERIAL AND METHODS Five dental ceramics (2 traditional feldspathic veneer porcelains [Vita Omega and Duceragold], 2 lithium disilicate pressable materials [Stylepress and Empress-2], and a pressable leucite-based material [Empress-1]) were tested for their ability to alter cellular mitochondrial dehydrogenase activity after fabrication using a tetrazolium assay, after aging for 2 weeks in a biologic solution and after post-aging polishing with either a fine diamond or diamond polishing paste. Cellular responses were compared with polytetrafluoroethylene controls (analysis of variance, Tukey pairwise post-hoc comparison, alpha=.05). RESULTS The feldspathic porcelains caused only mild (<25% of controls) mitochondrial suppression regardless of aging or polishing. The pressable leucite-based material initially caused a 5% stimulation (not significant) of mitochondrial activity, which decreased significantly (P<.05) by 30% with aging to levels comparable to the feldspathic porcelains, and did not change with polishing. Both lithium disilicate materials caused an initial suppression of mitochondrial activity that decreased significantly with aging, but Empress-2 was severely cytotoxic initially (<20% of controls, P<.01), and became more cytotoxic again after polishing. Stylepress was less cytotoxic initially (85% of controls, not significant) and did not become cytotoxic again after polishing. CONCLUSIONS Dental ceramics are not equivalent in their in vitro biologic effects, even within the same class of material, and biologic safety should not be assumed. Most ceramics caused only mild in vitro suppression of cell function to levels that would be acceptable on the basis of standards used to evaluate alloys and composites. However, 1 Li-disilicate material (Empress-2) exhibited cytotoxicity that would not be deemed biologically acceptable on the basis of prevailing empirical standards for dental alloys and composites.
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Affiliation(s)
- Regina L W Messer
- Dept. of Oral Biology, Medical College of Georgia School of Dentistry, Augusta 30912-1260, USA
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Abstract
Refractory ceramic fibers (RCFs) are man-made vitreous fibers commonly used in insulation applications above 1000 degrees C. Although they have been subjected to considerable toxicologic evaluation, only the pooled results from two rat inhalation studies provide data that may be suitable for performing a numerical risk assessment. Even in these inhalation studies, good evidence exists that the maximum tolerated dose (MTD) was exceeded and that pulmonary overload occurred, a condition that will cause tumors whatever the dust responsible. Indeed, a significant yield of tumors was only obtained at the highest dose tested. If these results are omitted, there is no statistically significant evidence of carcinogenicity within the RCF results. Although there is little evidence that overload-related tumors are relevant to human risk, we adopted a conservative approach to obtain the estimates of risk regardless of overload, using a biologically based model, the two-stage clonal expansion model, as well as various statistical models, including the benchmark dose model. We argue that the data favor the use of a biologically based model, which gives the best fit when the highest dose RCF exposures are omitted. Continuing with this model, we show that available data from the RCF experiment, less outliers, coupled with results from other experiments with man-made mineral fibers (MMVFs), demonstrate that all MMVFs are potentially carcinogenic, with any risk mediated by the fibers' biopersistence. Application of this "all MMVF data set" model yields a maximum likely estimate for RCF excess unit risk of 4.6 x 10(-5) (95% upper confidence limit = 9.2 x 10(-5) per fiber/ml). This implies that the risk from occupational exposure to RCFs at 1 fiber/ml for a typical working lifetime would not exceed 10(-4).
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Affiliation(s)
- J Turim
- Sciences International, Inc., 1800 Diagonal Road, Alexandria, VA 22314, USA.
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Abstract
When artificial hip or knee joints are implanted in the human body, they release metallic, ceramic, and polymeric debris into the surrounding tissues. The toxicity of the released particles is of two types: chemical, caused by the released soluble ions and monomers, and mechanical, a result of mechanical stimulation produced by the insoluble particles. In this study, the cytotoxicity of particles of TiO2, Al2O3, ZrO2, Si3N4, and SiC for murine fibroblasts and macrophages were examined to evaluate just their mechanical toxicity because these particles are not expected to release soluble metal ions. Different sizes and shapes of TiO2 particles were used to evaluate the effect of size and shape on particle cytotoxicity. The results suggest that the cytotoxicity of ceramic particles does not depend on their chemical species. Cytotoxicity levels were lower than those of corresponding metal ions, indicating that the mechanical toxicity of particles is lower than the chemical toxicity of released soluble ions and monomers. The differences in size did not affect the mechanical toxicity of these particles. The dendritic particles had a higher cytotoxicity level for macrophages than did spindle and spheric particles.
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Affiliation(s)
- Akiko Yamamoto
- Reconstitution Materials Group, Biomaterials Center, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
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Elias Z, Poirot O, Danière MC, Terzetti F, Binet S, Tomatis M, Fubini B. Surface reactivity, cytotoxicity, and transforming potency of iron-covered compared to untreated refractory ceramic fibers. J Toxicol Environ Health A 2002; 65:2007-2027. [PMID: 12490045 DOI: 10.1080/00984100290071360] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Untreated and iron-coated refractory ceramic fibers (RCFs) 1, 3, and 4 were examined for their potential to generate free radicals and to catalyze hydrogen peroxide decomposition in cell-free assays and were compared for cytotoxic and transforming potencies in Syrian hamster embryo (SHE) cell system. Coating with a high quantity of iron increased the capability of RCFs to generate hydroxyl radicals and to catalyze the decomposition of hydrogen peroxide. In the SHE cells, the untreated RCFs had varying ability to induce inhibition of cell proliferation, cytotoxicity (as measured by the colony-forming efficiency, CE) and morphological transformation, in a concentration-dependent manner. According to cytotoxic and transforming potencies, they ranged as follows: RCF3 > RCF1 > RCF4. The lethal concentration 50 (LC50; decrease of CE to 50% of controls after 7 d of treatment) expressed per number of RCF3 and RCF1/cm(2) of culture dish was 2.5 x 10(4) and 3.7 x 10(4), respectively, whereas RCF4 was not cytotoxic up to the highest concentration tested (23.7 x 10(4) fibers/cm(2)). At LC50, RCF3 was 1.4-fold more transforming than RCF1, and the weakest, RCF4, induced less than 1% transformation. Iron coating of RCF1 and RCF3 markedly attenuated their cytostatic, cytotoxic, and transforming potencies without a linear concentration-transformation relationship. In contrast, iron coating of RCF4 affected slightly its low transforming potency, although the growth inhibitory effect was reduced. The observed decrease rather than increase in the cytotoxic and transforming potencies of the active samples RCF1 and RCF3 by their coating with large amounts of ferric iron suggests that it is not the quantity or any form of iron on the surface of fibers but the iron, even in trace, in a particular redox and coordinate state that might play a role in the fiber's surface reactivity with regard to the biological material. Surface chemical functions involved in the interaction with the cell could be inactivated by the deposition of a high quantity of Fe(III) on the surface of fibers. Physicochemical studies correlated to biological effects is an approach for understanding the properties of solids related to a given biological response and for elucidating the cellular and molecular mechanisms.
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Affiliation(s)
- Zoé Elias
- Institut National de Recherche et de Sécurité, Vandoeuvre-lès-Nancy, France.
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Abstract
OBJECTIVES In orthodontic therapy, different materials are used and subjected to a damp oral environment, which can modify their properties. In order to evaluate the biocompatibility of metallic and non-metallic orthodontic appliances their in vitro cytotoxicity has been measured. METHODS Twenty-eight new and nine clinically used materials, including brackets, molar bands and archwires were used. The metallic materials were made of stainless steel, gold-plated steel, pure titanium, nickel-titanium, titanium-molybdenum and silver-based soldering alloy. The non-metallic materials were in polycarbonates and ceramics. After a release period of the material in the culture medium (0.1 mg/ml) for 3 and 14 days, the viability of fibroblasts L929 cultivated with this medium was compared to negative control with MTT assay. RESULTS The results showed the non-cytotoxicity of the materials. The metallic and non-metallic materials were similar in terms of cytotoxicity. The cytotoxicity of clinically used samples was equivalent to that of the same non-used samples, except a cytotoxic sample, at 14 days, corresponding to a soldered and clinically used molar band. The 3 day results were different from the 14 day results in six cases out of 37. SIGNIFICANCE In spite of the presence of one cytotoxic sample, the orthodontic materials can be considered as non cytotoxic. However, the practitioner should pay attention to the composition and the polish of soldering silver-based alloys containing copper and zinc in order to limit cytotoxic ion release. The cytotoxicity of the used sample related to ion release might be related to some clinical sub-acute effects related with orthodontic materials, thus a long term release period may be suitable to evaluate in vitro the sub-acute clinical effects of alloys.
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Affiliation(s)
- O Mockers
- U.F.R. Odontologie, Université Méditerranée, 27 boulevard Jean Moulin, 13005 cedex 5, Marseille, France
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Ignatius AA, Betz O, Augat P, Claes LE. In vivo investigations on composites made of resorbable ceramics and poly(lactide) used as bone graft substitutes. J Biomed Mater Res 2002; 58:701-9. [PMID: 11745524 DOI: 10.1002/jbm.10024] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Porous composites made of poly(L, DL-lactide) (PLA) and alpha-tricalcium phosphate (alpha-TCP) or the glass ceramic, GB14N, respectively, were investigated in a loaded implant model in sheep. Six, 12 and 24 months after implantation histological and biomechanical evaluation were performed and compared to autogenous bone transplants. No significant differences were observed between the composites. After 6 months, the interconnecting pores of the alpha-TCP-composite and the GB14N-composite were filled with newly formed bone (14 +/- 5% or 29 +/-15% of the implant, respectively) and soft tissue (30 +/-9% or 21 +/-12% of the implant, respectively). Only a mild inflammatory response was observed. The reaction was similar after 12 months. However, after 24 months a strong inflammatory reaction was seen. The newly formed bone was partly osteolytic. The adverse reaction occurred simultaneously to a significant reduction of the PLA component. The histological results were reflected by the biomechanical outcomes. Both composites showed compression strengths in the range of the autologous bone graft until 12 months of implantation. After 2 years, however, the strengths were significantly decreased. It is concluded that the new composites cannot yet be used for clinical application. An improvement in biocompatibility might be reached by a better coordination of the degradation times of the polymer and the ceramic component.
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Affiliation(s)
- A A Ignatius
- Institute of Orthopaedic Research and Biomechanics, University of Ulm, Helmholtzstrasse 14, 89081 Ulm, Germany.
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National Toxicology Program. Ceramic fibers (respirable size). Rep Carcinog 2002; 10:46-7. [PMID: 15318383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
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Abstract
Tricalcium phosphate ceramics (TCPs) are increasingly used as bone substitutes. They demonstrate good biocompatibility and degrade relatively slowly. New glass ceramics based on calcium alkali orthophosphates (Ca(2)KNa(PO(4))(2)) were developed that degrade faster than TCP but could have reduced biocompatibility due to their high solubility. Therefore, they were modified by a neutralizing surface treatment. The aim of this study was to evaluate the biocompatibility of some of these ceramics, GB1a, GB9, and GB14, which differ in the amount of added Na, K, Mg, or Si ions, with standard and modified surfaces. The in vitro cytotoxicity of the ceramics GB1a, GB9, and GB14 was determined by the agar diffusion and filter test and the microculture tetrazolium (MTT) assay. In order to investigate the influence of surface modification, these three ceramics were compared to their surface-treated counterparts, GB1aN, GB9N, and GB14N. GB1a, the ceramic with the highest in vitro solubility, showed the strongest toxic influence in all cell culture tests. GB9 and GB14 produced better results. In contrast, the counterparts with modified surfaces exhibited no (GB9N, GB14N) or weak (GB1aN) signs of cytotoxicity. It is concluded that the toxicity of the ceramics GB1a, GB9, and GB14 depends on their solubility. A positive influence of the surface treatment on in vitro biocompatibility was demonstrated. Therefore, the surface-treated glass ceramics could be promising materials for bone replacement.
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Affiliation(s)
- A A Ignatius
- Institute of Orthopaedic Research and Biomechanics, University of Ulm, Helmholtzstr. 14, 89081 Ulm, Germany.
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Butler K, Benghuzzi H, Puckett A. Cytological evaluation of the tissue-implant reaction associated with S/C and I/P implantation of ALCAP and HA bioceramics in vivo. Pathol Res Pract 2001; 197:29-39. [PMID: 11209814 DOI: 10.1078/0344-0338-00005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [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] [Indexed: 11/18/2022]
Abstract
It is well documented that several ceramic materials are highly compatible and non-immunogenic with host tissues. Recent studies have demonstrated the need for further investigation of these devices in vivo to further elucidate the possible mechanisms involved in biocompatibility. The purpose of this investigation was to study the morphological characteristics of the fibrous tissue capsule resulting from the implantation of aluminum calcium phosphate (ALCAP) and hydroxyapetite (HA) bioceramics. Implants of ALCAP and HA were implanted into 10 adult male rats subcutaneously (S/C) and intraperitoneally (I/P). At 90 days post-implantation, the animals were euthanized, and the ceramic devices, the fibrous tissue, and vital organs were harvested. Evaluation of routine stained sections (5 microm, hematoxylin & eosin) of the fibrous tissue capsule surrounding the HA and ALCAP ceramics revealed the following: 1) all the ceramic devices had fibrous connective tissue capsules of slightly varying degrees of thickness at the time of sacrifice, depending on the site of implantation and type of material, and 2) there were statistically significant differences (p < 0.05) in the numbers and types of cellular components with respect to implantation site. The number of macrophages, neutrophils, fibroblasts, degree of vascularity, and thickness of the fibrous tissue matrix was found to be statistically different between the S/C implanted ceramic groups. The number of macrophages, neutrophils, fibroblasts, and collagen content comparing the fibrous tissue surrounding the ALCAP and HA ceramics (I/P), was found to be statisically different.
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Affiliation(s)
- K Butler
- Department of Health Science, School of Health Related Professions, University of Mississippi Medical Center, Jackson, USA
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Butler K, Puckett A, Benghuzzi H. Quantitative analysis of the cellular components of the fibrous tissue matrix surrounding ALCAP, HA, and TCP bioceramics using adult male rats as a model. Biomed Sci Instrum 2001; 35:267-72. [PMID: 11143360] [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] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
This investigation was specifically an attempt to correlate the thickness of this fibrous capsule and the various histological components that are seen in the fibrous capsule surrounding ALCAP, HA, and TCP ceramics at the S/C and I/P implantation sites in order to further elucidate the mechanisms of tissue-implant interaction. Eighteen male albino rats were randomly divided into three experimental groups (n = 5/group) and one control (n = 3). Animals in Groups I, II, and III were implanted with the ALCAP, HA, and TCP ceramics, respectively. Animals in Group IV were not implanted and acted as the control group. At 90 days post-implantation, the animals in all groups were euthanized and the fibrous tissue surrounding the ceramic devices and internal organs were harvested. After routine histological processing, sections of tissue was stained with hematoxylin and eosin and evaluated using light microscopy. Analysis of the data revealed the following: 1) The presence of macrophages, neutrophils, fibroblasts, vascularity, and thickness of the fibrous tissue matrix was found to be statistically different among the subcutaneously implanted ceramic groups (ANOVA, p < 0.01). 2) The presence of collagen (S/C) is not statistically different among the three ceramic groups (ANOVA, p = 0.76). 3) The presence of macrophages, neutrophils, fibroblasts, and collagen comprising the fibrous tissue surrounding the ALCAP, HA, and TCP ceramics (I/P), was found to be statistically different (ANOVA, p < 0.01). 4) Vascularity and thickness of the fibrous tissue surrounding the three I/P ceramics were not found to be statistically different among the three ceramic groups (ANOVA, p > 0.05).
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Affiliation(s)
- K Butler
- University of Mississippi Medical Center, Jackson, MS 39216, USA
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Kim KA, Lee WK, Kim JK, Seo MS, Lim Y, Lee KH, Chae G, Lee SH, Chung Y. Mechanism of refractory ceramic fiber- and rock wool-induced cytotoxicity in alveolar macrophages. Int Arch Occup Environ Health 2001; 74:9-15. [PMID: 11196086 DOI: 10.1007/s004200000187] [Citation(s) in RCA: 28] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES Man-made vitreous fibers (MMVFs) can induce cytotoxicity in a way similar to that of other particles, including silica and asbestos fibers. However, as yet the mechanism of MMVF-induced cytotoxicity is still not clear. This report aims to clarify the mechanism of MMVF-induced cytotoxicity in the alveolar macrophage (AM). In this mechanism, an attempt to prove the involvement of the adenosine triphosphate (ATP) generation system and the polyinosinic acid-inhibitable scavenger receptors was made. METHODS Several parameters were observed for cytotoxicity, such as cell viability, the release of lactic dehydrogenase (LDH) and ATP levels in rat AM's that were treated with refractory ceramic fibers (RF2) and rock wool (RW1). A specially designed ATP generation system was used to determine the effect of MMVF on ATP generation. A scavenger receptor ligand was applied to evaluate the relationship between scavenger receptors and MMVF-induced ATP depletion. RESULTS A 3-(4,5-dimethylthiazol)-2,5-diphenyl tetrazolium bromide (MTT) assay indicated that both RF2 and RW1 caused a decrease in cell viability and this decrease was concentration-dependent. RF2 and RW1 increased the release of LDH with increasing fiber concentration. From these parameters, RF2 was shown to exhibit greater cytotoxicity than did RW1. Both fibers decreased the intracellular ATP content and this decrease was concentration-dependent. The decrease was more pronounced in RW1 than in RF2 at all fiber concentrations. These fibers suppressed succinate-triggered oxygen consumption. Polyinosinic acid, a ligand of the scavenger receptor, inhibited the MMVF-induced decrease in ATP concentration. CONCLUSION These results suggest that RF2 and RW1 can induce cytotoxicity and ATP depletion in the AM through the polyinosinic acid-inhibitable scavenger receptor. ATP depletion was the important factor in MMVF cytotoxicity, especially by RW1.
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Affiliation(s)
- K A Kim
- Department of Occupational and Environmental Medicine, St. Mary's Hospital, College of Medicine, Catholic University of Korea, Korea
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Abstract
Because the inhalation of asbestos, a naturally occurring, inorganic fibrous material, is associated with lung fibrosis and thoracic cancers, concerns have been raised about the possible health effects of synthetic vitreous fibers (SVFs). SVFs include a very broad variety of inorganic fibrous materials with an amorphous molecular structure. Traditionally, SVFs have been divided into three subcategories based on composition: fiberglass, mineral wool (rock, stone, and slag wools), and refractory ceramic fiber. For more than 50 years, the toxicologic potential of SVFs has been researched extensively using human epidemiology and a variety of laboratory studies. Here we review the research and its impact on hazard classification and regulation of SVFs. Large, ongoing epidemiology studies of SVF manufacturing workers have provided very little evidence of harmful effects in humans. Several decades of research using rodents exposed by inhalation have confirmed that SVF pulmonary effects are determined by the "Three D's", fiber dose (lung), dimension, and durability. Lung dose over time is determined by fiber deposition and biopersistence in the lung. Deposition is inversely related to fiber diameter. Biopersistence is directly related to fiber length and inversely related to fiber dissolution and fragmentation rates. Inhaled short fibers are cleared from the lung relatively quickly by mobile phagocytic cells, but long fibers persist until they dissolve or fragment. In contrast to asbestos, most of the SVFs tested in rodent inhalation studies cleared rapidly from the lung (were nonbiopersistent) and were innocuous. However, several relativley biopersistent SVFs induced chronic inflammation, lung scarring (fibrosis), and thoracic neoplasms. Thus, biopersistence of fibers is now generally recognized as a key determinant of the toxicologic potential of SVFs. In vitro dissolution of fibers in simulated extracellular fluid correlates fairly well with fiber biopersistence in the lung and pulmonary toxicity, but several exceptions suggest that biopersistence involves more than dissolution rate. Research demonstrating the relationship between biopersistence and SVF toxicity has provided a scientific basis for hazard classification and regulation of SVFs. For a nonhazardous classification, legislation recently passed by the European Union requires a respirable insulation wool to have a low lung-biopersistence or be noncarcinogenic in laboratory rats. U.S. fiberglass and mineral wool industries and the Occupational Health and Safety Administration (OSHA) have formed a voluntary Health and Safety Partnership Program (HSPP) that include: a voluntary permissible exposure level (PEL) in the workplace of 1 fiber/cc, a respiratory protection program for specified tasks, continued workplace air monitoring, and, where possible, the development of fiber formulations that do not persist in the lung. RCF manufacturers have implemented a Product Stewardship Program that includes: a recommended exposure guideline of 0.5 fibers/cc; a 5-year workplace air monitoring program; and research into the development of high-temperature-resistant, biosoluble fibers.
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Affiliation(s)
- T W Hesterberg
- Johns Manville Corporation, Littleton, CO 80162-5005, USA
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Mast RW, Yu CP, Oberdörster G, McConnell EE, Utell MJ. A retrospective review of the carcinogenicity of refractory ceramic fiber in two chronic fischer 344 rat inhalation studies: an assessment of the MTD and implications for risk assessment. Inhal Toxicol 2000; 12:1141-72. [PMID: 11114786 DOI: 10.1080/08958370050198511] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The purpose of this article is to review previous chronic inhalation studies in rats with refractory ceramic fiber (RCF), the mathematical modeling efforts to describe the deposition, clearance, and retention of RCF fiber in the rat and human, and the concept of "overload," and to assess the possibility that the maximum tolerated dose (MTD) was exceeded. Lastly, based on recent biopersistence and pulmonary clearance studies of several investigators with a particulate-free RCF, we examine the potential impact on the chronic RCF rat bioassay of coexposure to both RCF particulate and RCF fibers. The review concludes, inter alia, that RCF particulate coexposure probably had a major impact on the observed chronic adverse effects, that the MTD was probably exceeded at the highest exposure concentration of 30 mg/m(3) in the rat bioassay, and that inclusion of the highest dose in the risk assessment process may overstate human health risk if a linear rather than nonlinear model is used.
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Affiliation(s)
- R W Mast
- Everest Consulting Associates, 15 North Main Street, Cranbury, NJ 08512-3203, USA.
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Abstract
Synthetic vitreous fibers (SVFs) are a broad class of inorganic vitreous silicates used in a large number of applications including thermal and acoustical insulation and filtration. Historically, they have been grouped into somewhat artificial broad categories, e.g., glass, rock (stone), slag, or ceramic fibers based on the origin of the raw materials or the manufacturing process used to produce them. In turn, these broad categories have been used to classify SVFs according to their potential health effects, e.g., the International Agency for Research on Cancer and International Programme for Chemical Safety in 1988, based on the available health information at that time. During the past 10-15 years extensive new information has been developed on the health aspects of these fibers in humans, in experimental animals, and with in vitro test systems. Various chronic inhalation studies and intraperitoneal injection studies in rodents have clearly shown that within a given category of SVFs there can be a vast diversity of biological responses due to the different fiber compositions within that category. This information has been further buttressed by an in-depth knowledge of differences in the biopersistence of the various types of fibers in the lung after short-term exposure and their in vitro dissolution rates in fluids that mimic those found in the lung. This evolving body of information, which compliments and explains the results of chronic animal studies clearly show that these "broad" categories are somewhat archaic, oversimplistic, and do not represent current science. This new understanding of the relation between fiber composition, solubility, and biological activity requires a new classification system to more accurately reflect the potential health consequences of exposure to these materials. It is proposed that a new classification system be developed based on the results of short-term in vivo in combination with in vitro solubility studies. Indeed, the European Union has incorporated some of this knowledge, e.g., persistence in the lung into its recent Directive on fiber classification.
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