1
|
Hannah TJ, McCarvell WM, Kirsch T, Bedard J, Hynes T, Mayho J, Bamford KL, Vos CW, Kozak CM, George T, Masuda JD, Chitnis SS. Planar bismuth triamides: a tunable platform for main group Lewis acidity and polymerization catalysis. Chem Sci 2023; 14:4549-4563. [PMID: 37152250 PMCID: PMC10155930 DOI: 10.1039/d3sc00917c] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 03/14/2023] [Indexed: 05/09/2023] Open
Abstract
Geometric deformation in main group compounds can be used to elicit unique properties including strong Lewis acidity. Here we report on a family of planar bismuth(iii) complexes (cf. typically pyramidal structure for such compounds), which show a geometric Lewis acidity that can be further tuned by varying the steric and electronic features of the triamide ligand employed. The structural dynamism of the planar bismuth complexes was probed in both the solid and solution phase, revealing at least three distinct modes of intermolecular association. A modified Gutmann-Beckett method was used to assess their electrophilicity by employing trimethylphosphine sulfide in addition to triethylphosphine oxide as probes, providing insights into the preference for binding hard or soft substrates. Experimental binding studies were complemented by a computational assessment of the affinities and dissection of the latter into their intrinsic bond strength and deformation energy components. The results show comparable Lewis acidity to triarylboranes, with the added ability to bind two bases simultaneously, and reduced discrimination against soft substrates. We also study the catalytic efficacy of these complexes in the ring opening polymerization of cyclic esters ε-caprolactone and rac-lactide. The polymers obtained show excellent dispersity values and high molecular weights with low catalyst loadings used. The complexes retain their performance under industrially relevant conditions, suggesting they may be useful as less toxic alternatives to tin catalysts in the production of medical grade materials. Collectively, these results establish planar bismuth complexes as not only a novel neutral platform for main group Lewis acidity, but also a potentially valuable one for catalysis.
Collapse
Affiliation(s)
- Tyler J Hannah
- Chemistry Department, Dalhousie University 6274 Coburg Rd Halifax NS B3H 4R2 Canada
| | - W Michael McCarvell
- Chemistry Department, Dalhousie University 6274 Coburg Rd Halifax NS B3H 4R2 Canada
| | - Tamina Kirsch
- Chemistry Department, Dalhousie University 6274 Coburg Rd Halifax NS B3H 4R2 Canada
| | - Joseph Bedard
- Chemistry Department, Dalhousie University 6274 Coburg Rd Halifax NS B3H 4R2 Canada
| | - Toren Hynes
- Chemistry Department, Dalhousie University 6274 Coburg Rd Halifax NS B3H 4R2 Canada
| | - Jacqueline Mayho
- Chemistry Department, Dalhousie University 6274 Coburg Rd Halifax NS B3H 4R2 Canada
| | - Karlee L Bamford
- Chemistry Department, Dalhousie University 6274 Coburg Rd Halifax NS B3H 4R2 Canada
| | - Cyler W Vos
- Department of Chemistry, Memorial University of Newfoundland St. John's NL A1B 3X7 Canada
| | - Christopher M Kozak
- Department of Chemistry, Memorial University of Newfoundland St. John's NL A1B 3X7 Canada
| | - Tanner George
- Department of Chemistry, Saint Mary's University 923 Robie St. Halifax NS B3H 3C3 Canada
| | - Jason D Masuda
- Department of Chemistry, Saint Mary's University 923 Robie St. Halifax NS B3H 3C3 Canada
| | - S S Chitnis
- Chemistry Department, Dalhousie University 6274 Coburg Rd Halifax NS B3H 4R2 Canada
| |
Collapse
|
2
|
Kumar TDA, Swathi N, Subrahmanyam C, Satyanarayana K. Application of Design of Experiments (DoE) Approach for the Optimization of Phase-transfer Catalyzed Biginelli Dihydropyrimidinone (DHPM) Synthesis. LETT ORG CHEM 2021. [DOI: 10.2174/1570178617999200812133809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The conventional Biginelli synthesis is more cumbersome and produces lower yields. Several
improved methods are reported in the literature to replace the Biginelli catalyst. The design of biocompatible
organic transformation is a major concern and a versatile greener procedure to construct
Biginelli analogs is in great demand. Factorial design guided, energy-efficient, and versatile synthesis
of 3,4-dihydropyrimidin-2-(1H)-ones (DHPM) was developed. One-factor-at-a time (OFAT) and factorial
design (2<sup>3</sup>) studies were utilized for screening the independent variables. The optimum levels of
potential variables (benzyl-n-triethylammonium chloride (BTEAC) and glacial acetic acid) were determined
through studies. The factorial design (3<sup>2</sup>) analysis inferred the use of BTEAC (10.25 mol%)
and glacial acetic acid (7.6 ml) as optimal for the 60 min condensation. Thirteen new 3,4-
dihydropyrimidine-2-(1H)-one (DHPM) analogs were synthesized using optimized reaction conditions.
The quaternary ammonium ion of BTEAC stabilizes the polarization of carbonyl group in aryl aldehydes
and enolizable ketone (alkyl acetoacetate) to facilitate the cyclocondensation, in order to produce
DHPMs through N-acyliminium ion and Michael adducts formation. The biocompatible strategy, simple
product isolation (non-chromatographic method), and good to excellent yields are attractive features of
this new protocol. Hence, the newly developed methodology is superior to the literature methods.
Collapse
Affiliation(s)
- T. Durai Ananda Kumar
- Department of Pharmaceutical Chemistry, JSS College of Pharmacy, Mysuru, JSS Academy of Higher Education & Research, SS Nagara, Mysuru, 570 015, Karnataka,India
| | - N. Swathi
- Department of Pharmaceutical Chemistry, Gokaraju Rangaraju College of Pharmacy, Hyderabad, 500 090, Telangana,India
| | - C.V.S. Subrahmanyam
- Department of Pharmaceutics, Gokaraju Rangaraju College of Pharmacy, Hyderabad, 500 090, Telangana,India
| | - K. Satyanarayana
- Natco Pharma Ltd, Natco Research Center, B-13, Industrial Estate, Sanath Nagar, Hyderabad, 500 018, Telangana,India
| |
Collapse
|
3
|
Zhao Y, Ni X, Ye S, Gu ZG, Li Y, Ngai T. A Smart Route for Encapsulating Pd Nanoparticles into a ZIF-8 Hollow Microsphere and Their Superior Catalytic Properties. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:2037-2043. [PMID: 32036667 DOI: 10.1021/acs.langmuir.9b03731] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The encapsulation of catalytically active noble metal nanoparticles (NM NPs) into metal-organic frameworks (MOFs) represents an effective strategy for enhancing their catalytic performance. Despite a myriad of reports on the nanocomposites consisting of NM NPs and MOFs, it remains challenging to develop a sustainable and convenient method for realizing confined integration of NM NPs within a porous and hollow zinc-based MOF. Herein, a simple and well-designed approach is reported to the fabrication of Pd@ZIF-8 hollow microspheres with a number of Pd nanoparticles immobilized on the inner surface. This method capitalized on the use of polyvinylpyrrolidone (PVP)-stabilized polystyrene (PS) microspheres as templates, to harness the dual functions of PVP for reducing PdCl2 to generate Pd NPs and coordinating with zinc ions to grow ZIF-8 shells. Consequently, it avoids the complicated protocols involving surface treatment of template microspheres that conventionally adopts hazardous or costly agents. The obtained Pd@ZIF-8 hollow microspheres exhibit outstanding catalytic activity, size selectivity, and stability in the hydrogenation of alkenes. This study presents both the advances in the green synthesis and great potential of Pd@ZIF-8 hollow microspheres for catalytic applications.
Collapse
Affiliation(s)
- Yaqian Zhao
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, China
| | - Xinjiong Ni
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, China
| | - Sunjie Ye
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
| | - Zhi-Guo Gu
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, China
| | - Yunxing Li
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, China
| | - To Ngai
- Department of Chemistry, The Chinese University of Hong Kong, Shatin 9990077, N. T., Hong Kong
| |
Collapse
|
4
|
Younes M, Aggett P, Aguilar F, Crebelli R, Dusemund B, Filipič M, Frutos MJ, Galtier P, Gott D, Gundert-Remy U, Kuhnle GG, Lambré C, Leblanc JC, Lillegaard IT, Moldeus P, Mortensen A, Oskarsson A, Stankovic I, Waalkens-Berendsen I, Wright M, Di Domenico A, Van Loveren H, Giarola A, Horvath Z, Lodi F, Riolo F, Woutersen RA. Re-evaluation of stannous chloride (E 512) as food additive. EFSA J 2018; 16:e05295. [PMID: 32625934 PMCID: PMC7009391 DOI: 10.2903/j.efsa.2018.5295] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The Panel on Food Additives and Nutrient Sources added to Food (ANS) provides a scientific opinion re‐evaluating the safety of stannous chloride and stannous chloride dihydrate (E 512) as food additives. The Panel considered that adequate exposure and toxicity data were available. Stannous chloride is only permitted as food additives in one food category and no reply on the actual use level of stannous chloride (E 512) as a food additive and on its concentration in food was provided by any interested party. According to the Mintel's Global New Products Database (GNPD), stannous chloride was not labelled on any products in the EU nor in Norway. The regulatory maximum level exposure assessment scenario is based on the maximum permitted levels (MPLs) for stannous chloride (E 512), which is 25 mg Sn/kg. The mean exposure to stannous chloride (E 512) from its use as a food additive was below 1.3 μg Sn/kg body weight (bw) per day for all age groups. The 95th percentile of exposure to stannous chloride (E 512) ranged from 0.0 μg Sn/kg bw per day in all groups to 11.2 μg Sn/kg bw per day in adults. Absorption of stannous chloride from the gastrointestinal tract is low there is no concern with respect to carcinogenicity and genotoxicity. Gastrointestinal irritation was reported in humans after ingestion of a bolus dose of 40 mg Sn. The Panel concluded that stannous chloride (E 512) is of no safety concern in this current authorised use and use levels.
Collapse
|
5
|
Wunderlich G, Wendisch M, Aurich D, Runge R, Freudenberg R, Kotzerke J. Preincubation with Sn-complexes causes intensive intracellular retention of 99mTc in thyroid cells in vitro. Nuklearmedizin 2018; 51:179-85. [DOI: 10.3413/nukmed-0450-11-12] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 04/02/2012] [Indexed: 11/20/2022]
Abstract
SummaryTechnetium radiopharmaceuticals are well established in nuclear medicine. Besides its well-known gamma radiation, 99mTc emits an average of five Auger and internal conversion electrons per decay. The biological toxicity of these low-energy, high-LET (linear energy transfer) emissions is a controversial subject. One aim of this study was to estimate in a cell model how much 99mTc can be present in exposed cells and which radiobiological effects could be estimated in 99mTc-overloaded cells. Methods: Sodium iodine symporter (NIS)- positive thyroid cells were used. 99mTc-uptake studies were performed after preincubation with a non-radioactive (cold) stannous pyro - phosphate kit solution or as a standard 99mTc pyrophosphate kit preparation or with pure pertechnetate solution. Survival curves were analyzed from colony-forming assays. Results: Preincubation with stannous complexes causes irreversible intracellular radioactivity retention of 99mTc and is followed by further pertechnetate influx to an unexpectedly high 99mTc level. The uptake of 99mTc pertechnetate in NIS-positive cells can be modified using stannous pyrophosphate from 3–5% to >80%. The maximum possible cellular uptake of 99mTc was 90 Bq/cell. Compared with nearly pure extracellular irradiation from routine 99mTc complexes, cell survival was reduced by 3–4 orders of magnitude after preincubation with stannous pyrophosphate. Conclusions: Intra cellular 99mTc retention is related to reduced survival, which is most likely mediated by the emission of low-energy electrons. Our findings show that the described experiments constitute a simple and useful in vitro model for radiobiological investigations in a cell model.
Collapse
Affiliation(s)
- G Wunderlich
- Klinik und Poliklinik für Nuklearmedizin, Universitätsklinikum Carl Gustav Carus, Technische Universität, 01307 Dresden, Fetscherstr. 74, Germany.
| | | | | | | | | | | |
Collapse
|
6
|
Steinborn C, Diegel C, Garcia-Käufer M, Gründemann C, Huber R. Immunomodulatory effects of metal salts at sub-toxic concentrations. J Appl Toxicol 2016; 37:563-572. [PMID: 27714827 DOI: 10.1002/jat.3390] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 08/03/2016] [Accepted: 08/22/2016] [Indexed: 12/31/2022]
Abstract
Because different metals are used in complementary medicine for the treatment of diseases related to a dysfunction of the immune system, this study aimed at determining the immunomodulatory potential of Pb(NO3 )2 , AuCl3 , Cu(NO3 )2 , HgCl2 , AgNO3 , SnCl2 , AsCl3 and SbCl3 at sub-toxic concentrations and at assessing possible toxic side effects of low-concentrated metal preparations. The influence of the metal salts on primary human mononuclear cells was analyzed by measuring cell viability using the water-soluble tetrazolium salt assay, apoptosis and necrosis induction by annexin V/propidium iodide staining and proliferation by carboxyfluorescein diacetate succinimidyl ester staining and flow cytometry. Effects on T-cell activation were assessed with CD69 and CD25 expression using flow cytometry whereas CD83, CD86 and CD14 expression was measured to evaluate the influence on dendritic cell maturation. Alterations of interleukin-2 and interferon-γ secretion were detected by enzyme-linked immunosorbent assay and genotoxic effects were analyzed using the comet assay. At sub-toxic concentrations retardation of T-cell proliferation was caused by Pb(NO3 )2 , AuCl3 and Cu(NO3 )2 and inhibitory effects on interleukin-2 secretion were measured after incubation with Pb(NO3 )2 , AuCl3 , Cu(NO3 )2 , HgCl2 and AsCl3. Cu(NO3 )2 had immunosuppressive activity at dosages within the serum reference range for copper. All other metal salts showed effects at dosages above upper serum limits of normal. Therefore, only low-concentrated copper preparations are promising to have immunomodulatory potential. Toxic side effects of metal preparations used in complementary medicine are improbable because upper limits of metals set in the drinking water ordinance are either not exceeded or the duration of their application is limited. Copyright © 2016 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Carmen Steinborn
- Center for Complementary Medicine, Institute for Environmental Health Sciences and Hospital Infection Control, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Christoph Diegel
- Center for Complementary Medicine, Institute for Environmental Health Sciences and Hospital Infection Control, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Manuel Garcia-Käufer
- Center for Complementary Medicine, Institute for Environmental Health Sciences and Hospital Infection Control, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Carsten Gründemann
- Center for Complementary Medicine, Institute for Environmental Health Sciences and Hospital Infection Control, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Roman Huber
- Center for Complementary Medicine, Institute for Environmental Health Sciences and Hospital Infection Control, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| |
Collapse
|
7
|
Huang W, Cheng N, Qi Y, Zhang T, Jiang W, Li H, Zhang Q. Synthesis of high molecular weight poly(l-lactic acid) and poly(d-lactic acid) with improved thermal stability via melt/solid polycondensation catalyzed by biogenic creatinine. POLYMER 2014. [DOI: 10.1016/j.polymer.2014.01.054] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
8
|
|
9
|
Mattos JCPD, Matos VCD, Rodrigues MP, Oliveira MBND, Dantas FJS, Santos-Filho SD, Bernardo-Filho M, Caldeira-de-Araujo A. Evaluation of deoxyribonucleic acid toxicity induced by the radiopharmaceutical 99mTechnetium-Methylenediphosphonic acid and by stannous chloride in Wistar rats. Molecules 2012; 17:12974-83. [PMID: 23117436 PMCID: PMC6268462 DOI: 10.3390/molecules171112974] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 10/10/2012] [Accepted: 10/25/2012] [Indexed: 11/17/2022] Open
Abstract
Radiopharmaceuticals are employed in patient diagnostics and disease treatments. Concerning the diagnosis aspect, technetium-99m (99mTc) is utilized to label radiopharmaceuticals for single photon computed emission tomography (SPECT) due to its physical and chemical characteristics. 99mTc fixation on pharmaceuticals depends on a reducing agent, stannous chloride (SnCl2) being the most widely-utilized. The genotoxic, clastogenic and anegenic properties of the 99mTc-MDP(methylene diphosphonate used for bone SPECT) and SnCl2 were evaluated in Wistar rat blood cells using the Comet assay and micronucleus test. The experimental approach was to endovenously administer NaCl 0.9% (negative control), cyclophosphamide 50 mg/kg b.w. (positive control), SnCl2 500 μg/mL or 99mTc-MDP to animals and blood samples taken immediately before the injection, 3, and 24 h after (in the Comet assay) and 36 h after, for micronucleus test. The data showed that both SnCl2 and 99mTc-MDP-induced deoxyribonucleic acid (DNA) strand breaks in rat total blood cells, suggesting genotoxic potential. The 99mTc-MDP was not able to induce a significant DNA strand breaks increase in in vivo assays. Taken together, the data presented here points to the formation of a complex between SnCl2 in the radiopharmaceutical 99mTc-MDP, responsible for the decrease in cell damage, compared to both isolated chemical agents. These findings are important for the practice of nuclear medicine.
Collapse
Affiliation(s)
- José Carlos Pelielo De Mattos
- Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil.
| | | | | | | | | | | | | | | |
Collapse
|
10
|
|
11
|
Endonuclease IV is the main base excision repair enzyme involved in DNA damage induced by UVA radiation and stannous chloride. J Biomed Biotechnol 2010; 2010:376218. [PMID: 20300433 PMCID: PMC2840410 DOI: 10.1155/2010/376218] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2009] [Revised: 12/16/2009] [Accepted: 12/23/2009] [Indexed: 11/18/2022] Open
Abstract
Stannous chloride (SnCl2) and UVA induce DNA lesions through ROS. The aim of this work was to study the toxicity induced by UVA preillumination, followed by SnCl2 treatment. E. coli BER mutants were used to identify genes which could play a role in DNA lesion repair generated by these agents. The survival assays showed (i) The nfo mutant was the most sensitive to SnCl2; (ii) lethal synergistic effect was observed after UVA pre-illumination, plus SnCl2 incubation, the nfo mutant being the most sensitive; (iii) wild type and nfo mutants, transformed with pBW21 plasmid (nfo+) had their survival increased following treatments. The alkaline agarose gel electrophoresis assays pointed that (i) UVA induced DNA breaks and fpg mutant was the most sensitive; (ii) SnCl2-induced DNA strand breaks were higher than those from UVA and nfo mutant had the slowest repair kinetics; (iii) UVA + SnCl2 promoted an increase in DNA breaks than SnCl2 and, again, nfo mutant displayed the slowest repair kinetics. In summary, Nfo protects E. coli cells against damage induced by SnCl2 and UVA + SnCl2.
Collapse
|
12
|
Dånmark S, Finne-Wistrand A, Wendel M, Arvidson K, Albertsson AC, Mustafa K. Osteogenic Differentiation by Rat Bone Marrow Stromal Cells on Customized Biodegradable Polymer Scaffolds. J BIOACT COMPAT POL 2010. [DOI: 10.1177/0883911509358812] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In this report, poly(L-lactide-co-ε-caprolactone), poly(LLA-co-CL) and poly(L-lactide-co-1,5-dioxepan-2-one), poly(LLA-co-DXO) were evaluated and compared for potential use in bone tissue engineering constructs together with bone marrow stromal cells (BMSC). The copolymers were tailored to reduce the level of harmful tin residuals in the scaffolding. BMSC isolated from Sprague—Dawley rats were seeded onto the scaffolds and cultured in vitro for up to 21 days. Cell spreading and proliferation was analyzed after 72 h by scanning electron microscopy and thiazolyl blue tetrazolium bromide (MTT) conversion assay. Osteogenic differentiation of BMSC was evaluated by real-time PCR after 14 and 21 days of culture. Hydrophilicity was significantly different between poly(LLA-co-CL) and poly(LLA-co-DXO) with the latter being more hydrophilic. After 72 h, both scaffolds supported increased cell proliferation and the mRNA expression of osteocalcin and osteopontin was significantly increased after 21 days. Further investigation of these constructs, with lower levels of tin residuals, are being pursued.
Collapse
Affiliation(s)
- Staffan Dånmark
- Department of Clinical Dentistry - Center of Clinical Dental Research, Faculty of Medicine and Dentistry, University of Bergen, N-5009, Bergen, Norway, Department of Fibre and Polymer Technology, School of Chemical Science and Engineering, Royal Institute of Technology 100 44, Stockholm, Sweden
| | - Anna Finne-Wistrand
- Department of Fibre and Polymer Technology, School of Chemical Science and Engineering, Royal Institute of Technology 100 44, Stockholm, Sweden
| | - Mikael Wendel
- Centre for Oral Biology, Department of Odontology Karolinska Institutet, 141 04, Huddinge, Sweden
| | - Kristina Arvidson
- Department of Clinical Dentistry - Center of Clinical Dental Research, Faculty of Medicine and Dentistry, University of Bergen, N-5009, Bergen, Norway
| | - Ann-Christine Albertsson
- Department of Fibre and Polymer Technology, School of Chemical Science and Engineering, Royal Institute of Technology 100 44, Stockholm, Sweden
| | - Kamal Mustafa
- Department of Clinical Dentistry - Center of Clinical Dental Research, Faculty of Medicine and Dentistry, University of Bergen, N-5009, Bergen, Norway,
| |
Collapse
|
13
|
El-Makawy AI, Girgis SM, Khalil WK. Developmental and genetic toxicity of stannous chloride in mouse dams and fetuses. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2008; 657:105-10. [DOI: 10.1016/j.mrgentox.2008.08.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Revised: 07/09/2008] [Accepted: 08/04/2008] [Indexed: 10/21/2022]
|
14
|
Rocha GDS, Fonseca AS, Rodrigues MP, Dantas FJS, Caldeira-de-Araujo A, Santos R. Comet assay to determine DNA damage induced by food deprivation in rats. ACTA BIOLOGICA HUNGARICA 2008; 59:315-25. [PMID: 18839698 DOI: 10.1556/abiol.59.2008.3.5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The aim of this work was to evaluate, by comet assay, the possible inducing of DNA lesions in peripheral blood mononuclear cells of rats subjected to acute or chronic food deprivation. Wistar male rats were subjected to 72 h of partial (50%), or total acute food deprivation, and then allowed to recover for different time periods (24, 48 and 72 h). In other experiments, comet scores were determined in peripheral blood mononuclear cells of rats subjected to chronic food deprivation (25% and 50%) for 50 days. Blood aliquots were obtained before, during and after food deprivation. Comet assay was carried out, the comet units photographed and scored (class 0 up to 3). Acute and chronic food-deprived rats presented peripheral blood mononuclear cells with DNA lesions (comet classes 1, 2 and 3) and a significant increase (p<0.05) in the number of comet units compared with its basal level. The increase was proportional to acute food deprivation time, but after being taken off, it progressively returned to basal level after 48 h (partial group) or 72 h (total group). Chronic food-deprived rats presented a progressive increase of comet score up to 5 days, and a decrease thereafter to reach a basal level. Possible mechanisms of DNA lesions are discussed.
Collapse
Affiliation(s)
- Gabrielle de Souza Rocha
- Departamento de Farmacologia e Psicobiologia, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Avenida 28 de Setembro, 87, Fundos, Rio de Janeiro, Brasil
| | | | | | | | | | | |
Collapse
|
15
|
Fucic A, Merlo DF, Ceppi M, Lucas JN. Spontaneous abortions in female populations occupationally exposed to ionizing radiation. Int Arch Occup Environ Health 2007; 81:873-9. [PMID: 18058121 DOI: 10.1007/s00420-007-0281-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2007] [Accepted: 11/05/2007] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Exposure to radioisotopes of metals and halogen elements occurring in medical practice may cause spontaneous abortions. The potential role of occupational exposure to X-rays and internal radioisotopes on pregnancy outcome in childbearing age women employed in hospital departments were analyzed in order to estimate miscarriage risk. METHODS Over a period of 16 years, the occurrence of miscarriages in 61 women exposed to radioisotopes was compared to that reported in 170 X-ray exposed women. Chromosomal aberrations (CA) were measured in both radiation-exposed groups and in 53 non-exposed women. RESULTS Women exposed to radioisotopes experienced at least a threefold higher rate of spontaneous abortions than those exposed to X-ray (OR = 3.68, 95% CI = 1.39-9.74, P < 0.01). Although X-ray and radioisotopes exposed women had significantly higher levels of chromosome type frequency (0.51 +/- 0.82, and 0.63 +/- 0.99, respectively) than referents (0.17 +/- 0.34), there was no clear difference between radiation-exposed women. CONCLUSIONS For exposure levels within standard recommended guidelines, radioisotopes are far more likely to play a role in the occurrence of spontaneous abortions than X-rays. Such biological effect is not detectable by deviations in CA frequency.
Collapse
Affiliation(s)
- Aleksandra Fucic
- Institute for Medical Research and Occupational Health, 10000, Zagreb, Ksaverska c 2, Croatia.
| | | | | | | |
Collapse
|
16
|
Guedes AP, Cardoso VN, De Mattos JCP, Dantas FJS, Matos VC, Silva JCF, Bezerra RJAC, Caldeira-de-Araujo A. Cytotoxic and genotoxic effects induced by stannous chloride associated to nuclear medicine kits. Nucl Med Biol 2006; 33:915-21. [PMID: 17045172 DOI: 10.1016/j.nucmedbio.2006.07.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2006] [Revised: 07/11/2006] [Accepted: 07/18/2006] [Indexed: 11/23/2022]
Abstract
At present, more than 75% of routine nuclear medicine diagnostic procedures use technetium-99m (99mTc). The binding between 99mTc and the drug to obtain the radiopharmaceutical needs a reducing agent, with stannous chloride (SnCl2) being one of the most used. There are controversies about the cytotoxic, genotoxic and mutagenic effects of SnCl2 in the literature. Thus, the approaches below were used to better understand the biological effects of this salt and its association in nuclear medicine kits [methylenediphosphonate (MDP) bone scintigraphy and diethylenetriaminepentaacetic acid (DTPA) kidney and brain scintigraphy]: (i) bacterial inactivation experiments; (ii) agarose gel electrophoresis of supercoiled and linear plasmid DNA and (iii) bacterial transformation assay. The Escherichia coli strains used here were AB1157 (wild type) and BW9091 (xthA mutant). Data obtained showed that both MDP and SnCl2 presented a high toxicity, but this was not observed when they were assayed together in the kit, thereby displaying a mutual protect effect. DTPA salt showed a moderate toxicity, and once more, the DTPA kit provided protection, compared to the SnCl2 effect alone. The results suggest a possible complex formation, either MDP-SnCl2 or DTPA-SnCl2, originating an atoxic compound. On the other hand, SnCl2-induced cell inactivation and the decrease in bacterial transformation generated by DTPA found in XthA mutant strain suggest that the lack of this enzyme could be responsible for the effects observed, being necessary to induce DNA damage repair.
Collapse
Affiliation(s)
- Anderson P Guedes
- Departamento de Biofísica e Biometria, Universidade do Estado do Rio de Janeiro, Instituto de Biologia Roberto Alcantara Gomes, Rio de Janeiro 20551-030, Brazil.
| | | | | | | | | | | | | | | |
Collapse
|
17
|
de Mattos JCP, Lage C, Dantas FJS, Moraes MO, Nunes APM, Bezerra RJAC, Faria MVC, Leitão AC, Caldeira-de-Araujo A. Interaction of stannous chloride leads to alteration in DNA, triphosphate nucleotides and isolated bases. Mol Cell Biochem 2006; 280:173-9. [PMID: 16311920 DOI: 10.1007/s11010-005-8908-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2005] [Accepted: 06/17/2005] [Indexed: 11/28/2022]
Abstract
Stannous chloride (SnCl2) is a reducing chemical agent used in several man-made products. SnCl2 can generate reactive oxygen species (ROS); therefore, studies have been carried out in order to better understand its damaging action in biological systems. In this work, calf thymus DNA, triphosphate nucleotides and isolated bases were incubated with SnCl2 and the results were analyzed through UV spectrophotometry. The presence of stannous ions altered the absorption spectra of all three isolates. The amount of stannous ions associated to DNA was measured by atomic absorption spectrophotometry. Data showed that more than 40% of the initial SnCl2 concentration was present in the samples. Our results are in accordance with the damaging potential of this salt and present evidence that stannous ions can complex with DNA, inducing ROS in its vicinity, which may be responsible for the observed lesions.
Collapse
Affiliation(s)
- José C P de Mattos
- Departamento de Biofísica e Biometria, IBRAG, UERJ, Avenue 28 de Setembro, 87, Rio de Janeiro, RJ, 20551-030, Brazil
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Opinion of the Scientific Panel on Dietetic products, nutrition and allergies [NDA] related to the tolerable upper intake level of tin. EFSA J 2005. [DOI: 10.2903/j.efsa.2005.254] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
19
|
Hozalski RM, Esbri-Amador E, Chen CF. Comparison of stannous chloride and phosphate for lead corrosion control. ACTA ACUST UNITED AC 2005. [DOI: 10.1002/j.1551-8833.2005.tb10847.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
20
|
Ferreira-Machado SC, Rodrigues MP, Nunes APM, Dantas FJS, De Mattos JCP, Silva CR, Moura EG, Bezerra RJAC, Caldeira-de-Araujo A. Genotoxic potentiality of aqueous extract prepared from Chrysobalanus icaco L. leaves. Toxicol Lett 2004; 151:481-7. [PMID: 15261992 DOI: 10.1016/j.toxlet.2004.03.014] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2004] [Revised: 03/23/2004] [Accepted: 03/24/2004] [Indexed: 10/26/2022]
Abstract
Plants have been related to our lives, being used as medicine, regardless of scientific evidence of side effects. This work analyses the toxicological effects of Chrysobalanus icaco L. aqueous extract, used in different pathologies. It was studied through: (i) alteration of plasmid pUC 9.1 topology; (ii) survival of bacterial strains submitted, or not, to previous treatment with SnCl2; (iii) transformation efficiency of E. coli strain by the treatment with the plasmid pUC 9.1. In (i), the treatment of the plasmid resulted in DNA single-strand breaks (SSB). A decrease of the lethal effect induced by SnCl2 in presence of the extract was found, while no C. icaco bacterial survival reduction was observed. The transformation efficiency of the plasmid was also reduced. Results suggest that the extract could present a potential genotoxic effect, as demonstrated either by the induction of SSB in plasmid or in transformation efficiency experiments. Finally, it presents an antioxidant action.
Collapse
Affiliation(s)
- S C Ferreira-Machado
- Departamento de Biofísica e Biometria, Universidade do Estado do Rio de Janeiro, Instituto de Biologia Roberto Alcantara Gomes, Av. 28 de setembro, 87, Rio de Janeiro 20551-030, Brazil
| | | | | | | | | | | | | | | | | |
Collapse
|