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Ogundiran AI, Chang TL, Ivanov A, Kumari N, Nekhai S, Chandran PL. Shear-reversible clusters of HIV-1 in solution: stabilized by antibodies, dispersed by mucin. J Virol 2023; 97:e0075223. [PMID: 37712704 PMCID: PMC10617397 DOI: 10.1128/jvi.00752-23] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 07/03/2023] [Indexed: 09/16/2023] Open
Abstract
IMPORTANCE The phenomenon of reversible clustering is expected to further nuance HIV immune stealth because virus surfaces can escape interaction with antibodies (Abs) by hiding temporarily within clusters. It is well known that mucin reduces HIV virulence, and the current perspective is that mucin aggregates HIV-1 to reduce infections. Our findings, however, suggest that mucin is dispersing HIV clusters. The study proposes a new paradigm for how HIV-1 may broadly evade Ab recognition with reversible clustering and why mucin effectively neutralizes HIV-1.
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Affiliation(s)
- Ayobami I. Ogundiran
- Department of Chemical Engineering, College of Engineering and Architecture, Howard University, Washington, DC, USA
| | - Tzu-Lan Chang
- Department of Chemical Engineering, College of Engineering and Architecture, Howard University, Washington, DC, USA
| | - Andrey Ivanov
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC, USA
| | - Namita Kumari
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC, USA
- Department of Medicine, College of Medicine, Howard University, Washington, DC, USA
| | - Sergei Nekhai
- Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC, USA
- Department of Medicine, College of Medicine, Howard University, Washington, DC, USA
| | - Preethi L. Chandran
- Department of Chemical Engineering, College of Engineering and Architecture, Howard University, Washington, DC, USA
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Chicea D, Doroshkevich AS, Lyubchyk A. On the Possibility of Designing an Advanced Sensor with Particle Sizing Using Dynamic Light Scattering Time Series Spectral Entropy and Artificial Neural Network. Sensors (Basel) 2022; 22:s22103871. [PMID: 35632280 PMCID: PMC9145617 DOI: 10.3390/s22103871] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/09/2022] [Accepted: 05/16/2022] [Indexed: 02/05/2023]
Abstract
Dynamic Light Scattering is a well-established technique used in particle sizing. An alternative procedure for Dynamic Light Scattering time series processing based on spectral entropy computation and Artificial Neural Networks is described. An error analysis of the proposed method was carried out and the results on both the simulated and on the experimental DLS time series are presented in detail. The results reveal the possibility of designing an advanced sensor capable of detecting particles with a size bigger than a threshold using this alternative for processing the DLS time series.
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Affiliation(s)
- Dan Chicea
- Research Center for Complex Physical Systems, Faculty of Sciences, Lucian Blaga University of Sibiu, 550024 Sibiu, Romania
- Correspondence:
| | - Aleksandr S. Doroshkevich
- Donetsk Institute for Physics and Engineering Named After O.O. Galkin, NAS of Ukraine, 46 Prospect Nauky, 03028 Kyiv, Ukraine;
| | - Andriy Lyubchyk
- Nanotechcenter LLC, Krzhizhanovsky Str. 3, 03680 Kyiv, Ukraine;
- REQUIMTE, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quina de Torre, 2829-516 Caparica, Portugal
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3
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Chen J, Hao L, Hu J, Zhu K, Li Y, Xiong S, Huang X, Xiong Y, Tang BZ. A Universal Boronate-Affinity Crosslinking-Amplified Dynamic Light Scattering Immunoassay for Point-of-Care Glycoprotein Detection. Angew Chem Int Ed Engl 2021; 61:e202112031. [PMID: 34881816 DOI: 10.1002/anie.202112031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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: 09/04/2021] [Indexed: 12/21/2022]
Abstract
Herein, we report a universal boronate-affinity crosslinking-amplified dynamic light scattering (DLS) immunoassay for point-of-care (POC) glycoprotein detection in complex samples. This enhanced DLS immunoassay consists of two elements, i.e., antibody-coated magnetic nanoparticles (MNP@mAb) for target capture and DLS signal transduction, and phenylboronic acid-based boronate-affinity materials as crosslinking amplifiers. Upon the addition of targets, glycoproteins are first captured by MNP@mAb and amplified by target-induced crosslinking stemming from the selective binding between the boronic acid ligand and cis-diol-containing glycoprotein, thereby resulting in a remarkably increased DLS signal in the average nanoparticle size. Benefiting from the multivalent binding and fast boronate-affinity reaction between glycoproteins and crosslinkers, the proposed immunosensing strategy has achieved the ultrasensitive and rapid quantitative assay of glycoproteins at the fM level within 15 min. Overall, this work provides a promising and versatile design strategy for extending the DLS technique to detect glycoproteins even in the field or at POC.
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Affiliation(s)
- Jing Chen
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Liangwen Hao
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Jiaqi Hu
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Kang Zhu
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Yu Li
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Sicheng Xiong
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Xiaolin Huang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Yonghua Xiong
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Nanchang University, Nanchang, 330047, China
- Jiangxi-OAI Joint Research Institute, Nanchang University, Nanchang, 330047, China
| | - Ben Zhong Tang
- Shenzhen Institute of Aggregate Science and Technology, School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China
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4
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Minnelli C, Moretti P, Laudadio E, Gerelli Y, Pigozzo A, Armeni T, Galeazzi R, Mariani P, Mobbili G. Tuning curvature and phase behavior of monoolein bilayers by epigallocatechin-3-gallate: Structural insight and cytotoxicity. Colloids Surf B Biointerfaces 2021; 209:112171. [PMID: 34736221 DOI: 10.1016/j.colsurfb.2021.112171] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 07/17/2021] [Accepted: 10/18/2021] [Indexed: 10/20/2022]
Abstract
The use of glyceryl monooleate (GMO)-based nanoparticles has not yet been explored in overcoming the low bioavailability of Epigallocatechin-3-gallate (EGCG), a green tea polyphenol with a known anticancer activity. Since the inclusion of a guest molecule can affect the curvature and the supramolecular structure of fully hydrated GMO-based phase, the phase behavior of bulk and dispersed liquid crystalline systems containing EGCG were explored by Small Angle Neutron Scattering and X-Ray Diffraction experiments. Molecular Dynamic Simulations showed how the interaction of EGCG with polar heads of GMO strongly affects the curvature and packing of GMO phase. The EGCG encapsulation efficiency was determined in the nanodispersions and their size studied by Dynamic Light Scattering and Atomic Force Microscopy. A nanodispersed formulation has been optimized with a cytotoxic effect more than additive of GMO and EGCG.
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Affiliation(s)
- Cristina Minnelli
- Department DISVA, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Paolo Moretti
- Department DISVA, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Emiliano Laudadio
- Department SIMAU, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Yuri Gerelli
- Department DISVA, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | | | - Tatiana Armeni
- Department DISCO, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Roberta Galeazzi
- Department DISVA, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Paolo Mariani
- Department DISVA, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Giovanna Mobbili
- Department DISVA, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy.
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5
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Choy CH, He L, Tulumello D, Gajewska B, Terebiznik MR, Botelho RJ, Azizi A. Aggregation and Size Attributes Analysis of Unadsorbed and Adjuvant-adsorbed Antigens using a Multispectral Imaging Flow Cytometer Platform. J Pharm Sci 2021; 111:672-679. [PMID: 34742727 DOI: 10.1016/j.xphs.2021.10.037] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 10/30/2021] [Accepted: 10/30/2021] [Indexed: 11/26/2022]
Abstract
Various vaccine quality attributes should be monitored to ensure consistency, potency, purity, and safety of vaccine products prior to lot release. Vaccine particle size and protein antigen aggregation are two important considerations for particle-adsorbed vaccines. In this study, we evaluated the use of imaging flow cytometry as a potential all-in-one platform to measure adjuvant particle size and to detect protein aggregates through a combination of brightfield microscopy, side scatter detection, and fluorescence microscopy. An aluminum phosphate adjuvant was analyzed for size using the brightfield function, and the size measurement was compared against laser diffraction. Heat-induced protein aggregates of either unadsorbed antigens or aluminum phosphate adjuvant-adsorbed antigens were stained with the fluorescent ProteoStat aggregation dye, followed by detection and analysis using a combination of the brightfield and fluorescence microscopy functions. The change in aggregation of unadsorbed antigens was confirmed using dynamic light scattering. These results demonstrate the versatility of the imaging flow cytometry platform for the evaluation of multiple vaccine quality characteristics.
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Affiliation(s)
- Christopher H Choy
- Immunology platform, Analytical Sciences North America, Sanofi Pasteur, 1755 Steeles Avenue West, Toronto, ON, M2R 3T4, Canada; Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, M5B 2K3, Canada
| | - Liwei He
- Immunology platform, Analytical Sciences North America, Sanofi Pasteur, 1755 Steeles Avenue West, Toronto, ON, M2R 3T4, Canada
| | - David Tulumello
- Biochemistry platform, Analytical Sciences North America, Sanofi Pasteur, 1755 Steeles Avenue West, Toronto, Ontario, M2R 3T4, Canada
| | - Beata Gajewska
- Immunology platform, Analytical Sciences North America, Sanofi Pasteur, 1755 Steeles Avenue West, Toronto, ON, M2R 3T4, Canada
| | - Mauricio R Terebiznik
- Department of Biological Sciences, University of Toronto at Scarborough, Toronto, Ontario, M1C 1A4, Canada
| | - Roberto J Botelho
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, M5B 2K3, Canada
| | - Ali Azizi
- Immunology platform, Analytical Sciences North America, Sanofi Pasteur, 1755 Steeles Avenue West, Toronto, ON, M2R 3T4, Canada.
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6
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Nigro V, Angelini R, Bertoldo M, Buratti E, Franco S, Ruzicka B. Chemical-Physical Behaviour of Microgels Made of Interpenetrating Polymer Networks of PNIPAM and Poly(acrylic Acid). Polymers (Basel) 2021; 13:polym13091353. [PMID: 33919087 PMCID: PMC8122350 DOI: 10.3390/polym13091353] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 04/01/2021] [Accepted: 04/13/2021] [Indexed: 01/06/2023] Open
Abstract
Microgels composed of stimuli responsive polymers have attracted worthwhile interest as model colloids for theorethical and experimental studies and for nanotechnological applications. A deep knowledge of their behaviour is fundamental for the design of new materials. Here we report the current understanding of a dual responsive microgel composed of poly(N-isopropylacrylamide) (PNIPAM), a temperature sensitive polymer, and poly(acrylic acid) (PAAc), a pH sensitive polymer, at different temperatures, PAAc contents, concentrations, solvents and pH. The combination of multiple techniques as Dynamic Light Scattering (DLS), Raman spectroscopy, Small Angle Neutron Scattering (SANS), rheology and electrophoretic measurements allow to investigate the hydrodynamic radius behaviour across the typical Volume Phase Transition (VPT), the involved molecular mechanism and the internal particle structure together with the viscoelastic properties and the role of ionic charge in the aggregation phenomena.
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Affiliation(s)
- Valentina Nigro
- Istituto dei Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), Sede Sapienza, 00185 Roma, Italy; (V.N.); (E.B.)
| | - Roberta Angelini
- Istituto dei Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), Sede Sapienza, 00185 Roma, Italy; (V.N.); (E.B.)
- Dipartimento di Fisica, Sapienza Università, 00185 Rome, Italy
- Correspondence: (R.A.); (B.R.)
| | - Monica Bertoldo
- Dipartimento di Scienze Chimiche, Farmaceutiche ed Agrarie, Università degli Studi di Ferrara, 45121 Ferrara, Italy;
| | - Elena Buratti
- Istituto dei Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), Sede Sapienza, 00185 Roma, Italy; (V.N.); (E.B.)
| | - Silvia Franco
- Dipartimento di Scienze di Base e Applicate per l’Ingegneria (SBAI), Sapienza Università, 00185 Rome, Italy;
| | - Barbara Ruzicka
- Istituto dei Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), Sede Sapienza, 00185 Roma, Italy; (V.N.); (E.B.)
- Dipartimento di Fisica, Sapienza Università, 00185 Rome, Italy
- Correspondence: (R.A.); (B.R.)
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7
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Garting T, Stradner A. Synthesis and application of PEGylated tracer particles for measuring protein solution viscosities using Dynamic Light Scattering-based microrheology. Colloids Surf B Biointerfaces 2019; 181:516-523. [PMID: 31181434 DOI: 10.1016/j.colsurfb.2019.05.059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 05/22/2019] [Accepted: 05/23/2019] [Indexed: 10/26/2022]
Abstract
The measurement of flow properties, such as the zero shear viscosity, of protein solutions is of paramount importance for many applications such as pharmaceutical formulations, where the syringeability of physiologically effective doses is a key property. However, the determination of these properties with classical rheological methods is often challenging due to e.g. detrimental surface effects or simply the lack of sufficient material. A possible alternative is Dynamic Light Scattering-based microrheology, where the Brownian motion of tracer particles embedded in the protein solution is monitored to access the zero shear viscosity of the sample. The prime advantages of this method compared to classical rheology are the absence of disturbing surface effects and the up to two orders of magnitude smaller protein quantities needed for an entire concentration series. This Protocol provides a detailed description of the synthesis of sterically stabilized tracer particles with surface and overall particle properties specifically designed to investigate the viscosity of protein solutions up to concentrations close to the arrest transition. These particles are tailored to avoid protein-particle as well as particle-particle aggregation at various sample conditions and thus allow for an artifact-free application of Dynamic Light Scattering-based tracer microrheology to determine the flow behaviour of biological samples. The Protocol concludes with step by step instructions for the characterization of protein solutions using a combination of the tracer particles and an advanced dynamic light scattering technique yielding the concentration-dependent zero shear viscosity.
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Affiliation(s)
- Tommy Garting
- Division of Physical Chemistry, Department of Chemistry, Lund University, Lund, Sweden
| | - Anna Stradner
- Division of Physical Chemistry, Department of Chemistry, Lund University, Lund, Sweden; LINXS - Lund Institute of advanced Neutron and X-ray Science, Lund, Sweden.
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8
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Tasca E, Giudice AD, Galantini L, Schillén K, Giuliani AM, Giustini M. A fluorescence study of the loading and time stability of doxorubicin in sodium cholate/PEO-PPO-PEO triblock copolymer mixed micelles. J Colloid Interface Sci 2019; 540:593-601. [PMID: 30677613 DOI: 10.1016/j.jcis.2019.01.075] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 01/14/2019] [Accepted: 01/16/2019] [Indexed: 11/25/2022]
Abstract
HYPOTHESIS Doxorubicin hydrochloride (DX) is one of the most powerful anticancer agents though its clinical use is impaired by severe undesired side effects. DX encapsulation in nanocarrier systems has been introduced as a mean to reduce its toxicity. Micelles of the nonionic triblock copolymers of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) (PEO-PPO-PEO), are very promising carrier systems. The positive charge of DX confines the drug to the hydrophilic corona region of the micelles. The use of mixed micelles of PEO-PPO-PEO copolymers and a negatively charged bile salt should favour the solubilization of DX in the apolar core region of the micelles. EXPERIMENTS We studied the DX uptake in the micellar systems formed by sodium cholate (NaC) and the PEO100PPO65PEO100 (F127) copolymer, prepared with different mole ratios (MR = nNaC/nF127) in the range 0 ÷ 1. The systems were characterized by small angle X-ray scattering (SAXS) and dynamic light scattering (DLS); DX encapsulation was followed by steady-state and time-resolved fluorescence spectroscopy. FINDINGS The successful solubilization of DX in the host micellar systems did not affect their structure, as evidenced by both SAXS and DLS data. In the presence of NaC, DX experiences a more apolar environment as indicated by its characteristic fluorescent behaviour. The almost complete uptake of the drug occurred shortly after the sample preparation; however, time resolved fluorescence revealed a slow partition of DX between corona and core regions of the micelles. DX degradation in the mixed micellar systems was markedly reduced relative to aqueous DX solutions.
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Affiliation(s)
- Elisamaria Tasca
- Chemistry Department, University "La Sapienza", P.le Aldo Moro 5, 00185 Rome, Italy
| | | | - Luciano Galantini
- Chemistry Department, University "La Sapienza", P.le Aldo Moro 5, 00185 Rome, Italy; Centre for Colloid and Surface Science - C.S.G.I. Operative Unit of Bari, c/o Chemistry Department, University "Aldo Moro", Bari, Italy
| | - Karin Schillén
- Division of Physical Chemistry, Department of Chemistry, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden
| | | | - Mauro Giustini
- Chemistry Department, University "La Sapienza", P.le Aldo Moro 5, 00185 Rome, Italy; Centre for Colloid and Surface Science - C.S.G.I. Operative Unit of Bari, c/o Chemistry Department, University "Aldo Moro", Bari, Italy.
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9
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Aliyu A, Kariim I, Abdulkareem SA. Effects of aspect ratio of multi-walled carbon nanotubes on coal washery waste water treatment. J Environ Manage 2017; 202:84-93. [PMID: 28728004 DOI: 10.1016/j.jenvman.2017.07.011] [Citation(s) in RCA: 8] [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: 04/12/2017] [Revised: 06/26/2017] [Accepted: 07/06/2017] [Indexed: 05/28/2023]
Abstract
The dependency of adsorption behaviour on the aspect ratio of multi-walled carbon nanotubes (MWCNTs) has been explored. In this study, effect of growth temperature on yield and aspect ratio of MWCNTs by catalytic chemical vapour deposition (CCVD) method is reported. The result revealed that yield and aspect ratio of synthesised MWCNTs strongly depend on the growth temperature during CCVD operation. The resulting MWCNTs were characterized by High Resolution Transmission Electron Microscope (HRTEM), Dynamic Light Scattering (DLS) and X-ray diffraction (XRD) techniques to determine it diameter, hydrodynamic diameter and crystallinity respectively. Aspect ratio and length of the grown MWCNTs were determined from the HRTEM images with the hydrodynamic diameter using the modified Navier-Stokes and Stokes-Einstein equations. The effect of the prepared MWCNTs dosage were investigated on the Turbidity, Iron (Fe) and Lead (Pb) removal efficiency of coal washery effluent. The MWCNTs with higher length (58.17 μm) and diameter (71 nm) tend to show high turbidity and Fe removal, while MWCNTs with lower length (38.87 μm) and diameter (45 nm) tend to show high removal of Pb. Hence, the growth temperature during CCVD operation shows a great effluence on the aspect ratio of MWCNTs which determines it area of applications.
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Affiliation(s)
- Ahmed Aliyu
- Department of Chemical Sciences, Federal University Wukari, P.M.B. 1020, Taraba State, Nigeria; Nanotechnology Research Group, Centre for Genetic Engineering and Biotechnology, Federal University of Technology Minna, P.M.B. 65, Minna, Niger State, Nigeria.
| | - Ishaq Kariim
- Department of Chemical Engineering, School of Engineering and Engineering Technology, Federal University of Technology Minna, P.M.B. 65, Minna, Niger State, Nigeria; Nanotechnology Research Group, Centre for Genetic Engineering and Biotechnology, Federal University of Technology Minna, P.M.B. 65, Minna, Niger State, Nigeria
| | - Saka Ambali Abdulkareem
- Department of Chemical Engineering, School of Engineering and Engineering Technology, Federal University of Technology Minna, P.M.B. 65, Minna, Niger State, Nigeria; Nanotechnology Research Group, Centre for Genetic Engineering and Biotechnology, Federal University of Technology Minna, P.M.B. 65, Minna, Niger State, Nigeria
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10
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Chaari M, Theochari I, Papadimitriou V, Xenakis A, Ammar E. Encapsulation of carotenoids extracted from halophilic Archaea in oil-in-water (O/W) micro- and nano-emulsions. Colloids Surf B Biointerfaces 2018; 161:219-27. [PMID: 29080506 DOI: 10.1016/j.colsurfb.2017.10.042] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 09/26/2017] [Accepted: 10/14/2017] [Indexed: 11/24/2022]
Abstract
Carotenoids extracted from halophilc Archaea have potential health benefits. Their poor water-solubility and low bioavailability is a challenge to their incorporation into foods. The aim of this work was the carotenoids encapsulation into two oil-in-water (O/W) dispersions, to increase their use as functional food applications. A nanoemulsion produced by high pressure homogenization and a spontaneously formed microemulsion were conceived. The limonene was the dispersed oil phase, and mixtures of Triton X-100/Tween-80 (3:1) as emulsifiers and of water/glycerol (2:1) as the continuous aqueous phase. The microemulsion monophasic area was determined through the pseudo-ternary phase diagram. Dynamic Light Scattering was used for the structural characterization of the nano- and micro-emulsions in the presence of the carotenoids. Moreover, the radical scavenging activity of the encapsulated carotenoids was examined by Electron Paramagnetic Resonance spectroscopy. The results confirmed the delivery systems design effectiveness to encapsulate and stabilize the carotenoids for food applications.
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11
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Jain V, Hassan PA, Das B. Radiation-induced conformational changes in chromatin structure in resting human peripheral blood mononuclear cells. Int J Radiat Biol 2014; 90:1143-51. [PMID: 24844371 DOI: 10.3109/09553002.2014.925605] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
UNLABELLED Abstract Background: Ionizing radiation induces a plethora of DNA damage including double-strand breaks (DSB) that may trigger a series of events such as transcription, DNA repair and alteration in the conformation of chromatin structure in human cells. We have made an attempt to study the conformational changes in chromatin fibers in irradiated human peripheral blood mononuclear cells (PBMC) using Dynamic Light Scattering (DLS) as a new tool. MATERIALS AND METHODS Venous blood samples were collected from 10 random, healthy individuals with written informed consent, approved by institutional ethics committee. PBMC were separated from blood, irradiated with different doses of gamma radiation from 0.25-1.0 Gy. Native chromatin was isolated from irradiated PBMC and changes in the hydrodynamic diameter of the chromatin fiber were measured using DLS. Both dose response and time kinetics was studied in order to see the chromatin changes. Radiation-induced DNA double-strand breaks were measured using gamma-H2AX (histone 2A member X) as a biomarker using flow cytometry and foci were visualized in confocal microscopy. RESULTS A significant alteration in hydrodynamic diameter of the chromatin fiber was observed at lower doses (0.25 and 0.50 Gy), whereas at higher dose (1.0 Gy), the size of the chromatin fiber was comparable to unirradiated control. Among the 10 individuals studied, five individuals showed significant increase (p ≤ 0.002) in hydrodynamic size at 0.25 Gy whereas four individuals showed significant decrease (p ≤ 0.009) at 0.25 Gy. One individual did not show any significant difference as compared to control. However, dose-dependent increase in gamma-H2AX fluorescence signals as well as foci number was observed. Increased fragmentation of chromatin fiber was also observed using Atomic Force Microscopy at higher doses. CONCLUSION Radiation-induced DNA damage response can lead to individual specific conformational changes in chromatin structure at lower doses (0.25 Gy and 0.50 Gy) which can be detected using dynamic light scattering method in resting human PBMC.
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Affiliation(s)
- Vinay Jain
- Low Level Radiation Research Section, Radiation Biology and Health Sciences Division, Bio Science Group, Bhabha Atomic Research Centre , Trombay, Mumbai-400 085 , India
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12
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Lorenzen N, Nielsen SB, Yoshimura Y, Vad BS, Andersen CB, Betzer C, Kaspersen JD, Christiansen G, Pedersen JS, Jensen PH, Mulder FAA, Otzen DE. How epigallocatechin gallate can inhibit α-synuclein oligomer toxicity in vitro. J Biol Chem 2014; 289:21299-310. [PMID: 24907278 DOI: 10.1074/jbc.m114.554667] [Citation(s) in RCA: 138] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Oligomeric species of various proteins are linked to the pathogenesis of different neurodegenerative disorders. Consequently, there is intense focus on the discovery of novel inhibitors, e.g. small molecules and antibodies, to inhibit the formation and block the toxicity of oligomers. In Parkinson disease, the protein α-synuclein (αSN) forms cytotoxic oligomers. The flavonoid epigallocatechin gallate (EGCG) has previously been shown to redirect the aggregation of αSN monomers and remodel αSN amyloid fibrils into disordered oligomers. Here, we dissect EGCG's mechanism of action. EGCG inhibits the ability of preformed oligomers to permeabilize vesicles and induce cytotoxicity in a rat brain cell line. However, EGCG does not affect oligomer size distribution or secondary structure. Rather, EGCG immobilizes the C-terminal region and moderately reduces the degree of binding of oligomers to membranes. We interpret our data to mean that the oligomer acts by destabilizing the membrane rather than by direct pore formation. This suggests that reduction (but not complete abolition) of the membrane affinity of the oligomer is sufficient to prevent cytotoxicity.
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Affiliation(s)
- Nikolai Lorenzen
- From the Interdisciplinary Nanoscience Center, Center for Insoluble Protein Structures
| | - Søren B Nielsen
- From the Interdisciplinary Nanoscience Center, Center for Insoluble Protein Structures
| | - Yuichi Yoshimura
- From the Interdisciplinary Nanoscience Center, Center for Insoluble Protein Structures, Departments of Chemistry
| | - Brian S Vad
- From the Interdisciplinary Nanoscience Center, Center for Insoluble Protein Structures
| | | | | | - Jørn D Kaspersen
- From the Interdisciplinary Nanoscience Center, Departments of Chemistry
| | - Gunna Christiansen
- Biomedicine-Medical Immunology, Aarhus University, 8000 Aarhus C, Denmark
| | - Jan S Pedersen
- From the Interdisciplinary Nanoscience Center, Departments of Chemistry
| | | | - Frans A A Mulder
- From the Interdisciplinary Nanoscience Center, Center for Insoluble Protein Structures, Departments of Chemistry
| | - Daniel E Otzen
- From the Interdisciplinary Nanoscience Center, Center for Insoluble Protein Structures,
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Mebarek N, Aubert-Pouëssel A, Gérardin C, Vicente R, Devoisselle JM, Bégu S. Polymeric micelles based on poly(methacrylic acid) block-containing copolymers with different membrane destabilizing properties for cellular drug delivery. Int J Pharm 2013; 454:611-20. [PMID: 23792466 DOI: 10.1016/j.ijpharm.2013.06.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 05/30/2013] [Accepted: 06/03/2013] [Indexed: 11/22/2022]
Abstract
Poly(methacrylic acid)-b-poly(ethylene oxide) are double hydrophilic block copolymers, which are able to form micelles by complexation with a counter-polycation, such as poly-l-lysine. A study was carried out on the ability of the copolymers to interact with model membranes as a function of their molecular weights and as a function of pH. Different behaviors were observed: high molecular weight copolymers respect the membrane integrity, whereas low molecular weight copolymers with a well-chosen asymmetry degree can induce a membrane alteration. Hence by choosing the appropriate molecular weight, micelles with distinct membrane interaction behaviors can be obtained leading to different intracellular traffics with or without endosomal escape, making them interesting tools for cell engineering. Especially micelles constituted of low molecular weight copolymers could exhibit the endosomal escape property, which opens vast therapeutic applications. Moreover micelles possess a homogeneous nanometric size and show variable properties of disassembly at acidic pH, of stability in physiological conditions, and finally of cyto-tolerance.
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