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Kelpsiene E, Ekvall MT, Lundqvist M, Torstensson O, Hua J, Cedervall T. Review of ecotoxicological studies of widely used polystyrene nanoparticles. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2022; 24:8-16. [PMID: 34825687 DOI: 10.1039/d1em00375e] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
With polystyrene nanoparticles being widely used in various applications, there is a great need for deeper knowledge on the safety, fate and biological effects of these particles on both individual living organisms and the whole ecosystems. Due to this, there is a growing interest in performing ecotoxicological studies using model plastic nanoparticles, and consequently it generates an increasing number of published papers describing the negative impact on wildlife caused by such nanoparticles. Polystyrene is the most studied nanosized plastic, therefore this review focuses on research conducted with manufactured polystyrene nanoparticles. The aim of the present article is to provide a critical methodological outline of the existing ecotoxicological studies on the effects of polystyrene nanoparticles on aquatic organisms. Going through the published articles, we noted that particle characterization especially in the test medium, can be improved. The analysis also highlights the importance of purifying the polystyrene nanoparticles before studying its toxicity. Furthermore, the size characterization of such nanoparticles is underemphasized, and in future studies, authors should consider including more techniques to achieve this goal. Finally, short-term or direct exposure scenarios do not add the most environmentally relevant knowledge in terms of the toxicity caused by polystyrene nanoparticles.
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Affiliation(s)
- Egle Kelpsiene
- Department of Biochemistry and Structural Biology, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden.
- NanoLund, Lund University, Box 118, SE-221 00 Lund, Sweden
| | - Mikael T Ekvall
- Aquatic Ecology Unit, Department of Biology, Ecology Building, Lund University, SE-223 62 Lund, Sweden
- NanoLund, Lund University, Box 118, SE-221 00 Lund, Sweden
| | - Martin Lundqvist
- Department of Biochemistry and Structural Biology, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden.
- NanoLund, Lund University, Box 118, SE-221 00 Lund, Sweden
| | - Oscar Torstensson
- Department of Biochemistry and Structural Biology, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden.
| | - Jing Hua
- Department of Biochemistry and Structural Biology, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden.
| | - Tommy Cedervall
- Department of Biochemistry and Structural Biology, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden.
- NanoLund, Lund University, Box 118, SE-221 00 Lund, Sweden
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2
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Schlich M, Musazzi UM, Campani V, Biondi M, Franzé S, Lai F, De Rosa G, Sinico C, Cilurzo F. Design and development of topical liposomal formulations in a regulatory perspective. Drug Deliv Transl Res 2021; 12:1811-1828. [PMID: 34755281 PMCID: PMC8577404 DOI: 10.1007/s13346-021-01089-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/25/2021] [Indexed: 01/29/2023]
Abstract
The skin is the absorption site for drug substances intended to treat loco-regional diseases, although its barrier properties limit the permeation of drug molecules. The growing knowledge of the skin structure and its physiology have supported the design of innovative nanosystems (e.g. liposomal systems) to improve the absorption of poorly skin-permeable drugs. However, despite the dozens of clinical trials started, few topically applied liposomal systems have been authorized both in the EU and the USA. Indeed, the intrinsic complexity of the topically applied liposomal systems, the higher production costs, the lack of standardized methods and the more stringent guidelines for assessing their benefit/risk balance can be seen as causes of such inefficient translation. The present work aimed to provide an overview of the physicochemical and biopharmaceutical characterization methods that can be applied to topical liposomal systems intended to be marketed as medicinal products, and the current regulatory provisions. The discussion highlights how such methodologies can be relevant for defining the critical quality attributes of the final product, and they can be usefully applied based on the phase of the life cycle of a liposomal product: to guide the formulation studies in the early stages of development, to rationally design preclinical and clinical trials, to support the pharmaceutical quality control system and to sustain post-marketing variations. The provided information can help define harmonized quality standards able to overcome the case-by-case approach currently applied by regulatory agencies in assessing the benefit/risk of the topically applied liposomal systems.
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Affiliation(s)
- Michele Schlich
- Dipartimento Di Scienze Della Vita E Dell'Ambiente, Sezione Scienze del Farmaco, Università Di Cagliari, via Ospedale 72, 09124, Cagliari, Italy.,Laboratory of Nanotechnology for Precision Medicine, Istituto Italiano Di Tecnologia, via Morego 30, 16163, Genoa, Italy
| | - Umberto M Musazzi
- Department of Pharmaceutical Sciences, Università Degli Studi Di Milano, via G. Colombo 71, 20133, Milan, Italy
| | - Virginia Campani
- Dipartimento Di Farmacia, Università Degli Studi Di Napoli Federico II, via D. Montesano 49, 80131, Naples, Italy
| | - Marco Biondi
- Dipartimento Di Farmacia, Università Degli Studi Di Napoli Federico II, via D. Montesano 49, 80131, Naples, Italy
| | - Silvia Franzé
- Department of Pharmaceutical Sciences, Università Degli Studi Di Milano, via G. Colombo 71, 20133, Milan, Italy
| | - Francesco Lai
- Dipartimento Di Scienze Della Vita E Dell'Ambiente, Sezione Scienze del Farmaco, Università Di Cagliari, via Ospedale 72, 09124, Cagliari, Italy
| | - Giuseppe De Rosa
- Dipartimento Di Farmacia, Università Degli Studi Di Napoli Federico II, via D. Montesano 49, 80131, Naples, Italy
| | - Chiara Sinico
- Dipartimento Di Scienze Della Vita E Dell'Ambiente, Sezione Scienze del Farmaco, Università Di Cagliari, via Ospedale 72, 09124, Cagliari, Italy
| | - Francesco Cilurzo
- Department of Pharmaceutical Sciences, Università Degli Studi Di Milano, via G. Colombo 71, 20133, Milan, Italy.
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da Silva MM, Ribeiro GH, de Camargo MS, Ferreira AG, Ribeiro L, Barbosa MIF, Deflon VM, Castelli S, Desideri A, Corrêa RS, Ribeiro AB, Nicolella HD, Ozelin SD, Tavares DC, Batista AA. Ruthenium(II) Diphosphine Complexes with Mercapto Ligands That Inhibit Topoisomerase IB and Suppress Tumor Growth In Vivo. Inorg Chem 2021; 60:14174-14189. [PMID: 34477373 DOI: 10.1021/acs.inorgchem.1c01539] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Ruthenium(II) complexes (Ru1-Ru5), with the general formula [Ru(N-S)(dppe)2]PF6, bearing two 1,2-bis(diphenylphosphino)ethane (dppe) ligands and a series of mercapto ligands (N-S), have been developed. The combination of these ligands in the complexes endowed hydrophobic species with high cytotoxic activity against five cancer cell lines. For the A549 (lung) and MDA-MB-231 (breast) cancer cell lines, the IC50 values of the complexes were 288- to 14-fold lower when compared to cisplatin. Furthermore, the complexes were selective for the A549 and MDA-MB-231 cancer cell lines compared to the MRC-5 nontumor cell line. The multitarget character of the complexes was investigated by using calf thymus DNA (CT DNA), human serum albumin, and human topoisomerase IB (hTopIB). The complexes potently inhibited hTopIB. In particular, complex [Ru(dmp)(dppe)2]PF6 (Ru3), bearing the 4,6-diamino-2-mercaptopyrimidine (dmp) ligand, effectively inhibited hTopIB by acting on both the cleavage and religation steps of the catalytic cycle of this enzyme. Molecular docking showed that the Ru1-Ru5 complexes have binding affinity by active sites on the hTopI and hTopI-DNA, mainly via π-alkyl and alkyl hydrophobic interactions, as well as through hydrogen bonds. Complex Ru3 displayed significant antitumor activity against murine melanoma in mouse xenograph models, but this complex did not damage DNA, as revealed by Ames and micronucleus tests.
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Affiliation(s)
- Monize M da Silva
- Departamento de Química, Universidade Federal de São Carlos, CP 676, CEP 13565-905 São Carlos, São Paulo, Brazil
| | - Gabriel H Ribeiro
- Departamento de Química, Universidade Federal de São Carlos, CP 676, CEP 13565-905 São Carlos, São Paulo, Brazil
| | - Mariana S de Camargo
- Departamento de Química, Universidade Federal de São Carlos, CP 676, CEP 13565-905 São Carlos, São Paulo, Brazil
| | - Antônio G Ferreira
- Departamento de Química, Universidade Federal de São Carlos, CP 676, CEP 13565-905 São Carlos, São Paulo, Brazil
| | - Leandro Ribeiro
- Departamento de Química, Universidade Federal de São Carlos, CP 676, CEP 13565-905 São Carlos, São Paulo, Brazil
| | - Marília I F Barbosa
- Departamento de Química, Universidade Federal de São Carlos, CP 676, CEP 13565-905 São Carlos, São Paulo, Brazil
| | - Victor M Deflon
- Instituto de Química de São Carlos, Universidade de São Paulo, CEP 13565-905 São Carlos, São Paulo, Brazil
| | - Silvia Castelli
- Dipartimento di Biologia, Università Tor Vergata di Roma, 00133 Rome, Italy
| | | | - Rodrigo S Corrêa
- Departamento de Química, Universidade Federal de Ouro Preto, CEP 35400-000 Ouro Preto, Minas Gerais, Brazil
| | - Arthur B Ribeiro
- Universidade de Franca, CEP 14404-600, Franca, São Paulo, Brazil
| | | | - Saulo D Ozelin
- Universidade de Franca, CEP 14404-600, Franca, São Paulo, Brazil
| | - Denise C Tavares
- Universidade de Franca, CEP 14404-600, Franca, São Paulo, Brazil
| | - Alzir A Batista
- Departamento de Química, Universidade Federal de São Carlos, CP 676, CEP 13565-905 São Carlos, São Paulo, Brazil
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Vo TD, Schneider AL, Poon GMK, Wilson WD. DNA-facilitated target search by nucleoproteins: Extension of a biosensor-surface plasmon resonance method. Anal Biochem 2021; 629:114298. [PMID: 34252439 PMCID: PMC8427768 DOI: 10.1016/j.ab.2021.114298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 06/30/2021] [Indexed: 10/20/2022]
Abstract
To extend the value of biosensor-SPR in the characterization of DNA recognition by nucleoproteins, we report a comparative analysis of DNA-facilitated target search by two ETS-family transcription factors: Elk1 and ETV6. ETS domains represent an attractive system for developing biosensor-based techniques due to a broad range of physicochemical properties encoded within a highly conserved DNA-binding motif. Building on a biosensor approach in which the protein is quantitatively sequestered and presented to immobilized cognate DNA as nonspecific complexes, we assessed the impact of intrinsic cognate and nonspecific affinities on long-range (intersegmental) target search. The equilibrium constants of DNA-facilitated binding were sensitive to the intrinsic binding properties of the proteins such that their relative specificity for cognate DNA were reinforced when binding occurred by transfer vs. without nonspecific DNA. Direct measurement of association and dissociation kinetics revealed ionic features of the activated complex that evidenced DNA-facilitated dissociation, even though Elk1 and ETV6 harbor only a single DNA-binding surface. At salt concentrations that masked the effects of nonspecific pre-binding at equilibrium, the dissociation kinetics of cognate binding were nevertheless distinct from conditions under which nonspecific DNA was absent. These results further strengthen the significance of long-range DNA-facilitated translocation in the physiologic environment.
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Affiliation(s)
- Tam D Vo
- Department of Chemistry, Georgia State University, USA
| | | | - Gregory M K Poon
- Department of Chemistry, Georgia State University, USA; Center for Diagnostics and Therapeutics, Georgia State University, USA.
| | - W David Wilson
- Department of Chemistry, Georgia State University, USA; Center for Diagnostics and Therapeutics, Georgia State University, USA.
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Hallan SS, Sguizzato M, Esposito E, Cortesi R. Challenges in the Physical Characterization of Lipid Nanoparticles. Pharmaceutics 2021; 13:pharmaceutics13040549. [PMID: 33919859 PMCID: PMC8070758 DOI: 10.3390/pharmaceutics13040549] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/08/2021] [Accepted: 04/12/2021] [Indexed: 12/13/2022] Open
Abstract
Nano-sized drug transporters have become an efficient approach with considerable commercial values. Nanomedicine is not only limited to drug delivery by means of different administration routes, such as intravenous, oral, transdermal, nasal, pulmonary, and more, but also has applications in a multitude of areas, such as a vaccine, antibacterial, diagnostics and imaging, and gene delivery. This review will focus on lipid nanosystems with a wide range of applications, taking into consideration their composition, properties, and physical parameters. However, designing suitable protocol for the physical evaluation of nanoparticles is still conflicting. The main obstacle is concerning the sensitivity, reproducibility, and reliability of the adopted methodology. Some important techniques are compared and discussed in this report. Particularly, a comparison between different techniques involved in (a) the morphologic characterization, such as Cryo-TEM, SEM, and X-ray; (b) the size measurement, such as dynamic light scattering, sedimentation field flow fractionation, and optical microscopy; and (c) surface properties, namely zeta potential measurement, is described. In addition, an amperometric tool in order to investigate antioxidant activity and the response of nanomaterials towards the skin membrane has been presented.
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Affiliation(s)
- Supandeep Singh Hallan
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, I-44121 Ferrara, Italy; (S.S.H.); (M.S.); (E.E.)
| | - Maddalena Sguizzato
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, I-44121 Ferrara, Italy; (S.S.H.); (M.S.); (E.E.)
| | - Elisabetta Esposito
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, I-44121 Ferrara, Italy; (S.S.H.); (M.S.); (E.E.)
| | - Rita Cortesi
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, I-44121 Ferrara, Italy; (S.S.H.); (M.S.); (E.E.)
- Biotechnology Interuniversity Consortium (C.I.B.), Ferrara Section, University of Ferrara, I-44121 Ferrara, Italy
- Correspondence:
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Pogribna M, Koonce NA, Mathew A, Word B, Patri AK, Lyn-Cook B, Hammons G. Effect of titanium dioxide nanoparticles on DNA methylation in multiple human cell lines. Nanotoxicology 2020; 14:534-553. [PMID: 32031460 DOI: 10.1080/17435390.2020.1723730] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 01/07/2020] [Accepted: 01/24/2020] [Indexed: 12/27/2022]
Abstract
Nanoscale titanium dioxide (TiO2) is manufactured in wide scale, with a range of applications in consumer products. Significant toxicity of TiO2 nanoparticles has, however, been recognized, suggesting considerable risk to human health. To evaluate fully their toxicity, assessment of the epigenetic action of these nanoparticles is critical. However, only few studies are available examining capability of nanoparticles to alter epigenetic integrity. In the present study, the effect of TiO2 nanoparticles exposure on DNA methylation, a major epigenetic mechanism, was investigated in in vitro cellular model systems. A panel of cells relevant to portals of human exposure (Caco-2 (colorectal), HepG2 (liver), NL20 (lung), and A-431 (skin)) was exposed to TiO2 nanoparticles to assess effects on global methylation, gene-specific methylation, and expression levels of DNA methyltransferases, MBD2, and UHRF1. Global methylation was determined by enzyme-linked immunosorbent assay-based immunochemical analysis. Degree of promoter methylation across a defined panel of genes was evaluated using EpiTect Methyl II Signature PCR System Array technology. Expression of DNMT1, DNMT3a, DNMT3b, MBD2, and URHF1 was quantified by qRT-PCR. Decrease in global DNA methylation in cell lines Caco-2, HepG2, and A-431 exposed to TiO2 nanoparticles was shown. Across four cell lines, eight genes (CDKN1A, DNAJC15, GADD45A, GDF15, INSIG1, SCARA3, TP53, and BNIP3) were identified in which promotors were methylated after exposure. Altered expression of these genes is associated with disease etiology. The results also revealed aberrant expression of epigenetic regulatory genes involved in DNA methylation (DNMT1, DNMT3a, DNMT3b, MBD2, and UHRF1) in TiO2 exposed cells, which was cell type dependent. Findings from this study clearly demonstrate the impact of TiO2 nanoparticles exposure on DNA methylation in multiple cell types, supporting potential involvement of this epigenetic mechanism in the toxicity of TiO2 nanoparticles. Hence for complete assessment of potential risk from nanoparticle exposure, epigenetic studies are critical.
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Affiliation(s)
- Marta Pogribna
- Division of Biochemical Toxicity, FDA/National Center for Toxicological Research, Jefferson, AR, USA
| | - Nathan A Koonce
- Nanotechology Core, FDA/National Center for Toxicological Research, Jefferson, AR, USA
| | - Ammu Mathew
- Nanotechology Core, FDA/National Center for Toxicological Research, Jefferson, AR, USA
| | - Beverly Word
- Division of Biochemical Toxicity, FDA/National Center for Toxicological Research, Jefferson, AR, USA
| | - Anil K Patri
- Nanotechology Core, FDA/National Center for Toxicological Research, Jefferson, AR, USA
| | - Beverly Lyn-Cook
- Division of Biochemical Toxicity, FDA/National Center for Toxicological Research, Jefferson, AR, USA
| | - George Hammons
- Division of Biochemical Toxicity, FDA/National Center for Toxicological Research, Jefferson, AR, USA
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Clayton KN, Berglund GD, Linnes JC, Kinzer-Ursem TL, Wereley ST. DNA Microviscosity Characterization with Particle Diffusometry for Downstream DNA Detection Applications. Anal Chem 2017; 89:13334-13341. [PMID: 29148723 DOI: 10.1021/acs.analchem.7b03513] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Analytical characterization of DNA microviscosity provides critical biophysical insights into nuclear crowding, nucleic acid based pharmaceutical development, and nucleic acid based biosensor device design. However, most viscosity characterization methods require large sample volumes and destructive testing. In contrast, particle diffusometry permits in situ analysis of DNA microviscosity with short measurement times (8 s) using small volumes (<3 μL) which are compatible with DNA preparatory procedures. This unconventional biosensing approach involves measuring the change in sample viscosity using image processing and correlation-based algorithms. Particle diffusometry requires only a fluorescence microscope equipped with a charge-coupled device (CCD) camera and is a nondestructive measurement method. We use particle diffusometry to characterize the effect of DNA topology, length, and concentration on solution viscosity. In addition, we use particle diffusometry to detect the amplification of DNA from Staphylococcus aureus and Klebsiella pneumoniae, two pathogens commonly related to neonatal sepsis. Successful characterization of pathogen amplification with particle diffusometry provides a new opportunity to apply viscosity characterization toward downstream applications in nucleic acid based pathogen detection.
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Affiliation(s)
- Katherine N Clayton
- School of Mechanical Engineering, and ‡Weldon School of Biomedical Engineering, Purdue University , West Lafayette, Indiana 47906, United States
| | - Gregory D Berglund
- School of Mechanical Engineering, and ‡Weldon School of Biomedical Engineering, Purdue University , West Lafayette, Indiana 47906, United States
| | - Jacqueline C Linnes
- School of Mechanical Engineering, and ‡Weldon School of Biomedical Engineering, Purdue University , West Lafayette, Indiana 47906, United States
| | - Tamara L Kinzer-Ursem
- School of Mechanical Engineering, and ‡Weldon School of Biomedical Engineering, Purdue University , West Lafayette, Indiana 47906, United States
| | - Steven T Wereley
- School of Mechanical Engineering, and ‡Weldon School of Biomedical Engineering, Purdue University , West Lafayette, Indiana 47906, United States
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Bhattacharjee S. DLS and zeta potential - What they are and what they are not? J Control Release 2016; 235:337-351. [PMID: 27297779 DOI: 10.1016/j.jconrel.2016.06.017] [Citation(s) in RCA: 1759] [Impact Index Per Article: 219.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 06/08/2016] [Accepted: 06/09/2016] [Indexed: 02/07/2023]
Abstract
Adequate characterization of NPs (nanoparticles) is of paramount importance to develop well defined nanoformulations of therapeutic relevance. Determination of particle size and surface charge of NPs are indispensable for proper characterization of NPs. DLS (dynamic light scattering) and ZP (zeta potential) measurements have gained popularity as simple, easy and reproducible tools to ascertain particle size and surface charge. Unfortunately, on practical grounds plenty of challenges exist regarding these two techniques including inadequate understanding of the operating principles and dealing with critical issues like sample preparation and interpretation of the data. As both DLS and ZP have emerged from the realms of physical colloid chemistry - it is difficult for researchers engaged in nanomedicine research to master these two techniques. Additionally, there is little literature available in drug delivery research which offers a simple, concise account on these techniques. This review tries to address this issue while providing the fundamental principles of these techniques, summarizing the core mathematical principles and offering practical guidelines on tackling commonly encountered problems while running DLS and ZP measurements. Finally, the review tries to analyze the relevance of these two techniques from translatory perspective.
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Affiliation(s)
- Sourav Bhattacharjee
- School of Veterinary Medicine, University College Dublin (UCD), Belfield, Dublin 4, Ireland.
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9
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Bauer KC, Schermeyer MT, Seidel J, Hubbuch J. Impact of polymer surface characteristics on the microrheological measurement quality of protein solutions – A tracer particle screening. Int J Pharm 2016; 505:246-54. [DOI: 10.1016/j.ijpharm.2016.03.047] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 03/23/2016] [Accepted: 03/24/2016] [Indexed: 11/15/2022]
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Hekmat A, Saboury AA, Moosavi-Movahedi AA. The toxic effects of mobile phone radiofrequency (940 MHz) on the structure of calf thymus DNA. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2013; 88:35-41. [PMID: 23164448 DOI: 10.1016/j.ecoenv.2012.10.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 10/15/2012] [Accepted: 10/19/2012] [Indexed: 06/01/2023]
Abstract
Currently, the biological effects of nonionizing electromagnetic fields (EMFs) including radiofrequency (RF) radiation have been the subject of numerous experimental and theoretical studies. The aim of this study is to evaluate the possible biological effects of mobile phone RF (940 MHz, 15 V/m and SAR=40 mW/kg) on the structure of calf thymus DNA (ct DNA) immediately after exposure and 2 h after 45 min exposure via diverse range of spectroscopic instruments. The UV-vis and circular dichroism (CD) experiments depict that mobile phone EMFs can remarkably cause disturbance on ct DNA structure. In addition, the DNA samples, immediately after exposure and 2 h after 45 min exposure, are relatively thermally unstable compared to the DNA solution, which was placed in a small shielded box (unexposed ct DNA). Furthermore, the exposed DNA samples (the DNA samples that were exposed to 940 MHz EMF) have more fluorescence emission when compared with the unexposed DNA, which may have occurred attributable to expansion of the exposed DNA structure. The results of dynamic light scattering (DLS) and zeta potential experiments demonstrate that RF-EMFs lead to increment in the surface charge and size of DNA. The structure of DNA immediately after exposure is not significantly different from the DNA sample 2 h after 45 min exposure. In other words, the EMF-induced conformational changes are irreversible. Collectively, our results reveal that 940 MHz can alter the structure of DNA. The displacement of electrons in DNA by EMFs may lead to conformational changes of DNA and DNA disaggregation. Results from this study could have an important implication on the health effects of RF-EMFs exposure. In addition, this finding could proffer a novel strategy for the development of next generation of mobile phone.
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Affiliation(s)
- Azadeh Hekmat
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
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MoradpourHafshejani S, Hedley JH, Haigh AO, Pike AR, Tuite EM. Synthesis and binding of proflavine diazides as functional intercalators for directed assembly on DNA. RSC Adv 2013. [DOI: 10.1039/c3ra43090a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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