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Matson JB, Steele AQ, Mase JD, Schulz MD. Polymer Characterization by Size-Exclusion Chromatography with Multi-Angle Light Scattering (SEC-MALS): A Tutorial Review. Polym Chem 2024; 15:127-142. [PMID: 39070757 PMCID: PMC11281244 DOI: 10.1039/d3py01181j] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
This tutorial review presents the theory and application of SEC-MALS with minimal equations and a focus on synthetic polymer characterization, serving as an entry point for polymer scientists who want to learn more about SEC-MALS. We discuss the principles of static light scattering, outline its capability to generate absolute weight-average molar mass values, and extend its application to SEC-MALS. Practical elements are emphasized, enabling researchers to appreciate how values forM n , M w , and Đ are determined in an SEC-MALS experiment and how experimental conditions and input values, such as the specific refractive index increment ( d n / d c ), influence the results. Several illustrative SEC-MALS experiments demonstrate the impact of separation quality onM n (as opposed toM w ), the appearance of contaminants in SEC chromatograms from sample preparation, the influence of concentration on data quality, and how polymer topology affects molecular weight characterization in SEC. Finally, we address practical considerations, common issues, and persistent misconceptions.
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Affiliation(s)
- John B Matson
- Virginia Tech, Department of Chemistry and Macromolecules Innovation Institute
| | - Anna Q Steele
- Virginia Tech, Department of Chemistry and Macromolecules Innovation Institute
| | - Jonathan D Mase
- Virginia Tech, Department of Chemistry and Macromolecules Innovation Institute
| | - Mirchael D Schulz
- Virginia Tech, Department of Chemistry and Macromolecules Innovation Institute
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2
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Deng JZ, Jia X, Zong C, He J, Ha S, Zhuang P. Characterization of pneumococcal serotype 7F in vaccine conjugation. Glycoconj J 2023; 40:565-573. [PMID: 37402017 PMCID: PMC10638203 DOI: 10.1007/s10719-023-10125-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 06/09/2023] [Accepted: 06/14/2023] [Indexed: 07/05/2023]
Abstract
Streptococcus pneumoniae is a highly invasive bacterial pathogen that can cause a range of illnesses. Pneumococcal capsular polysaccharides (CPS) are the main virulence factors that causes invasive pneumococcal disease (IPD). Pneumococcal CPS serotype 7F along with a few other serotypes is more invasive and likely to cause IPD. Therefore, 7F is a target for pneumococcal vaccine development, and is included in the two recently approved multi-valent pneumococcal conjugated vaccines, i.e. VAXNEUVANCE and PREVNAR 20.To support process and development of our 15-valent pneumococcal conjugated vaccine (PCV15), chromatographic methods have been developed for 7F polysaccharide and conjugate characterization. A size-exclusion chromatography (SEC) method with UV, light scattering and refractive index detections was employed for concentration, size and conformation analysis. A reversed-phase ultra-performance liquid chromatography (RP-UPLC) method was used for analysis of conjugate monosaccharide composition and degree of conjugation. The collective information obtained by these chromatographic analysis provided insights into the pneumococcal conjugate and conjugation process.
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Affiliation(s)
- James Z Deng
- Vaccine Analytical Research & Development, 770 Sumneytown Pike, P. O. Box 4, West Point, PA, WP46-3305, 19486, USA.
| | - Xiujuan Jia
- Small Molecule Analytical Research & Development, Analytical Research & Development Merck & Co., Inc, Rahway, NJ, USA
| | - Chengli Zong
- Vaccine Analytical Research & Development, 770 Sumneytown Pike, P. O. Box 4, West Point, PA, WP46-3305, 19486, USA
| | - Jian He
- Vaccine Analytical Research & Development, 770 Sumneytown Pike, P. O. Box 4, West Point, PA, WP46-3305, 19486, USA
| | - Sha Ha
- Vaccine Analytical Research & Development, 770 Sumneytown Pike, P. O. Box 4, West Point, PA, WP46-3305, 19486, USA
| | - Ping Zhuang
- Vaccine Analytical Research & Development, 770 Sumneytown Pike, P. O. Box 4, West Point, PA, WP46-3305, 19486, USA
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3
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Li H, Kang Y, Zhang B, Wu J, Hua X, Jiang K. Accurate Quantitation of the Phenyl Group in Methylphenylsilicone Oils by GPC-UV. Chromatographia 2023. [DOI: 10.1007/s10337-023-04248-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2023]
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4
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Garcia A, Blum SA. Polymer Molecular Weight Determination via Fluorescence Lifetime. J Am Chem Soc 2022; 144:22416-22420. [PMID: 36459633 DOI: 10.1021/jacs.2c10036] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Control of polymer molecular weight is critical for tailoring structure-function properties; however, traditional molecular weight characterization techniques have limited ability to determine the molecular weight of polymers in real time without sample removal from the reaction mixture, with spatial resolution, and of insoluble polymers. In this work, a fluorescence lifetime imaging microscopy (FLIM) method was developed that overcomes these limitations. The method is demonstrated with polynorbornene and polydicyclopentadiene, polymers derived from ruthenium-catalyzed ring-opening metathesis polymerization (ROMP). The polymer Mw, ranging from 35 to 570 kg/mol as determined by gel-permeation chromatography, was quantitatively correlated with the fluorescence lifetime. The revealed correlation then enabled time-resolved measurement of Mw during an ongoing ROMP reaction, requiring only 1 s per measurement (of a 45 μm × 45 μm polymer sample area), and provided spatial resolution, resulting in simultaneous characterization of polymer morphology. To provide the fluorescence signal, the initial reaction solutions contained a very low doping of a reactive norbornene monomer labeled with fluorescent boron dipyrromethene (BODIPY), such that 1 in every 107 monomers contained a fluorophore. The resulting FLIM visualization method enables the rapid determination of the molecular weights of growing polymers without removal from the reaction mixture and regardless of polymer solubility.
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Affiliation(s)
- Antonio Garcia
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
| | - Suzanne A Blum
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
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5
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Deng JZ, Lin J, Chen M, Lancaster C, Zhuang P. Characterization of High Molecular Weight Pneumococcal Conjugate by SEC-MALS and AF4-MALS. Polymers (Basel) 2022; 14:3769. [PMID: 36145915 PMCID: PMC9501040 DOI: 10.3390/polym14183769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 09/06/2022] [Accepted: 09/06/2022] [Indexed: 11/25/2022] Open
Abstract
Infections by Streptococcus pneumoniae can cause serious pneumococcal diseases and other medical complications among patients. Polysaccharide-based vaccines have been successfully developed as prophylactic agents against such deadly bacterial infections. In the 1980s, PNEUMOVAX® 23 were introduced as the first pneumococcal polysaccharide vaccines (PPSV). Later, pneumococcal polysaccharides were conjugated to a carrier protein to improve immune responses. Pneumococcal conjugate vaccines (PCV) such as PREVNAR® and VAXNEUVANCE™ have been developed. Of the more than 90 pneumococcal bacteria serotypes, serotype 1 (ST-1) and serotype 4 (ST-4) are the two main types that cause invasive pneumococcal diseases (IPD) that could lead to morbidity and mortality. Development of a novel multi-valent PCV against these serotypes requires extensive biophysical and biochemical characterizations of each monovalent conjugate (MVC) in the vaccine. To understand and characterize these high molecular weight (Mw) polysaccharide protein conjugates, we employed the multi-angle light scattering (MALS) technique coupled with size-exclusion chromatography (SEC) separation and asymmetrical flow field flow fractionation (AF4). MALS analysis of MVCs from the two orthogonal separation mechanisms helps shed light on the heterogeneity in conformation and aggregation states of each conjugate.
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Affiliation(s)
- James Z. Deng
- Vaccine Analytical Research & Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Jason Lin
- Wyatt Technology Corporation, Goleta, CA 93117, USA
| | | | - Catherine Lancaster
- Vaccine Analytical Research & Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Ping Zhuang
- Vaccine Analytical Research & Development, Merck & Co., Inc., Rahway, NJ 07065, USA
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6
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Deng JZ, Lancaster C, Winters MA, Phillips KM, Zhuang P, Ha S. Multi-attribute characterization of pneumococcal conjugate vaccine by Size-exclusion chromatography coupled with UV-MALS-RI detections. Vaccine 2022; 40:1464-1471. [DOI: 10.1016/j.vaccine.2022.01.042] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 01/08/2022] [Accepted: 01/20/2022] [Indexed: 01/06/2023]
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7
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Pan X, Ding M, Li L. Experimental Validation on Average Conformation of a Comblike Polystyrene Library in Dilute Solutions: Universal Scaling Laws and Abnormal SEC Elution Behavior. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c01029] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Xuejun Pan
- Food Science and Processing Research Center, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China
- Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - Mingming Ding
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
| | - Lianwei Li
- Food Science and Processing Research Center, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China
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8
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Song Q, Cheng Z, Kariuki M, Hall SCL, Hill SK, Rho JY, Perrier S. Molecular Self-Assembly and Supramolecular Chemistry of Cyclic Peptides. Chem Rev 2021; 121:13936-13995. [PMID: 33938738 PMCID: PMC8824434 DOI: 10.1021/acs.chemrev.0c01291] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Indexed: 01/19/2023]
Abstract
This Review focuses on the establishment and development of self-assemblies governed by the supramolecular interactions between cyclic peptides. The Review first describes the type of cyclic peptides able to assemble into tubular structures to form supramolecular cyclic peptide nanotubes. A range of cyclic peptides have been identified to have such properties, including α-peptides, β-peptides, α,γ-peptides, and peptides based on δ- and ε-amino acids. The Review covers the design and functionalization of these cyclic peptides and expands to a recent advance in the design and application of these materials through their conjugation to polymer chains to generate cyclic peptide-polymer conjugates nanostructures. The Review, then, concentrates on the challenges in characterizing these systems and presents an overview of the various analytical and characterization techniques used to date. This overview concludes with a critical survey of the various applications of the nanomaterials obtained from supramolecular cyclic peptide nanotubes, with a focus on biological and medical applications, ranging from ion channels and membrane insertion to antibacterial materials, anticancer drug delivery, gene delivery, and antiviral applications.
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Affiliation(s)
- Qiao Song
- Department
of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.
| | - Zihe Cheng
- Department
of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.
| | - Maria Kariuki
- Department
of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.
| | | | - Sophie K. Hill
- Department
of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.
| | - Julia Y. Rho
- Department
of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.
| | - Sébastien Perrier
- Department
of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.
- Warwick Medical
School, University of Warwick, Coventry CV4 7AL, U.K.
- Faculty
of Pharmacy and Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
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9
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Hua Y, Su Y, Zhang H, Liu N, Wang Z, Gao X, Gao J, Zheng A. Poly(lactic-co-glycolic acid) microsphere production based on quality by design: a review. Drug Deliv 2021; 28:1342-1355. [PMID: 34180769 PMCID: PMC8245074 DOI: 10.1080/10717544.2021.1943056] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Poly(lactic-co-glycolic acid) (PLGA) has garnered increasing attention as a candidate drug delivery polymer owing to its favorable properties, including its excellent biocompatibility, biodegradability, non-toxicity, non-immunogenicity, and mechanical strength. PLAG are specifically used as microspheres for the sustained/controlled and targeted delivery of hydrophilic or hydrophobic drugs, as well as biological therapeutic macromolecules, including peptide and protein drugs. PLGAs with different molecular weights, lactic acid (LA)/glycolic acid (GA) ratios, and end groups exhibit unique release characteristics, which is beneficial for obtaining diverse therapeutic effects. This review aims to analyze the composition of PLGA microspheres, and understand the manufacturing process involved in their production, from a quality by design perspective. Additionally, the key factors affecting PLGA microsphere development are explored as well as the principles involved in the synthesis and degradation of PLGA and its interaction with active drugs. Further, the effects elicited by microcosmic conditions on PLGA macroscopic properties, are analyzed. These conditions include variations in the organic phase (organic solvent, PLGA, and drug concentration), continuous phase (emulsifying ability), emulsifying stage (organic phase and continuous phase interaction, homogenization parameters), and solidification process (relationship between solvent volatilization rate and curing conditions). The challenges in achieving consistency between batches during manufacturing are addressed, and continuous production is discussed as a potential solution. Finally, potential critical quality attributes are introduced, which may facilitate the optimization of process parameters.
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Affiliation(s)
- Yabing Hua
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Yuhuai Su
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Hui Zhang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Nan Liu
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Zengming Wang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Xiang Gao
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Jing Gao
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Aiping Zheng
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
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10
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Walsh DJ, Wade MA, Rogers SA, Guironnet D. Challenges of Size-Exclusion Chromatography for the Analysis of Bottlebrush Polymers. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c01357] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Dylan J. Walsh
- Department of Chemical and Biomolecular Engineering, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Matthew A. Wade
- Department of Chemical and Biomolecular Engineering, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Simon A. Rogers
- Department of Chemical and Biomolecular Engineering, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Damien Guironnet
- Department of Chemical and Biomolecular Engineering, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
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11
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Starch and Glycogen Analyses: Methods and Techniques. Biomolecules 2020; 10:biom10071020. [PMID: 32660096 PMCID: PMC7407607 DOI: 10.3390/biom10071020] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 07/06/2020] [Accepted: 07/07/2020] [Indexed: 01/16/2023] Open
Abstract
For complex carbohydrates, such as glycogen and starch, various analytical methods and techniques exist allowing the detailed characterization of these storage carbohydrates. In this article, we give a brief overview of the most frequently used methods, techniques, and results. Furthermore, we give insights in the isolation, purification, and fragmentation of both starch and glycogen. An overview of the different structural levels of the glucans is given and the corresponding analytical techniques are discussed. Moreover, future perspectives of the analytical needs and the challenges of the currently developing scientific questions are included.
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12
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Netopilík M, Podzimek S. Retention Mechanism of Branched Macromolecules in Size Exclusion Chromatography. ACS OMEGA 2020; 5:14254-14260. [PMID: 32596561 PMCID: PMC7315423 DOI: 10.1021/acsomega.9b03952] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 02/04/2020] [Indexed: 06/11/2023]
Abstract
The theory of Stockmayer in the modifications of Thurmond and Zimm has been used for the description of the size exclusion chromatography separation of randomly branched molecules with tetrafunctional branch points. It is assumed that free chain ends, created by the branching process, cause the molecules to be entrapped in the pores of the column packing with the time of their release given by the exponential law characteristic for the monomolecular reactions. Using this assumption, the anomalous elution behavior of such molecules can be modeled. With increasing elution volume, the average values of radius of gyration and, to a lesser degree, of molecular weight decrease and, after passing a minimum, again increase in the low-molecular weight region.
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Affiliation(s)
- Miloš Netopilík
- Institute
of Macromolecular Chemistry, Academy of
Sciences of the Czech Republic, Heyrovský Sq. 2, Prague 6 162 06, Czech Republic
| | - Stepan Podzimek
- Analytical
Chemistry, Synpo, S. K. Neumanna 1316, Pardubice CZ 53207, Czech Republic
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13
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Branched PLGA derivatives with tailored drug delivery properties. ACTA PHARMACEUTICA (ZAGREB, CROATIA) 2020; 70:63-75. [PMID: 31677370 DOI: 10.2478/acph-2020-0011] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/26/2019] [Indexed: 01/19/2023]
Abstract
Despite several shortcomings such as extreme hydrophobicity, low drug capacity, characteristic triphasic drug release pattern with a high burst effect, poly(lactic-co-glycolic acid derivatives are widely used in drug delivery. Most frequent attempts to improve their properties are blending with other polymers or synthesis of block copolymers. We introduce a new class of branched poly(lactic-co-glycolic acid) derivatives as promising biodegradable carriers for prolonged or targeted drug release systems, employed as thin adhesive films, solid dispersions, in situ forming implants or nanoparticles. A series of poly(lactic-co-glycolic acid) derivatives with lower molar mass and star or comb architecture were synthesized by a simple, catalyst free, direct melt polycondensation method not requiring purification of the obtained sterile product by precipitation. Branching monomers used were mannitol, pentaerythritol, dipentaerythritol, tripentaerythritol and polyacrylic acid. The products were characterized by molar mass averages, average branching ratio, rheological and thermal properties.
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14
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Neupane S, Bittkau KS, Alban S. Size distribution and chain conformation of six different fucoidans using size-exclusion chromatography with multiple detection. J Chromatogr A 2020; 1612:460658. [PMID: 31703890 DOI: 10.1016/j.chroma.2019.460658] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 10/12/2019] [Accepted: 10/24/2019] [Indexed: 12/13/2022]
Abstract
Fucoidans represent an intriguing class of fucose-containing sulfated polysaccharides. The biological activities of these polysaccharides are related to their compositional and structural parameters, whereby their degree of sulfation, as well as molecular weight (MW) distribution and chain conformation play important roles. Modern NMR and mass spectrometry techniques allow elucidating details of the glycan structure, but not the structure of the whole molecules in their native state. Accordingly, the knowledge about the latter of the fucoidans is currently still limited. Contrary to traditional MW determination by SEC with column calibration, SEC with triple detection provides not only the absolute Mw, but can also give information on additional molecule characteristics. In the present study, we used this method to compare six fucoidans extracted from Fucus vesiculosus (FV), F. serratus (FS), F. evanescens (FE), Dictyosiphon foeniculaceus (DF), Laminaria digitata (LD), and Saccharina latissima (SL) concerning their molar mass (Mw, Mn, Mp, dispersity) and size (rms radius, Rh) characteristics and distribution as well as their chain conformation in solution. The tested fucoidans displayed considerable structural diversity including large differences in their MW profiles and showed to be heterogeneously composed. Fuc-FV and Fuc-SL showed the broadest MW distributions, those from Fuc-FE and Fuc-DF the narrowest ones. Most of the fucoidan fractions (except for Fuc-DF) turned out to exist as expanded flexible chains in PBS solution. The conformation data suggest branched structures with partly long side chains. The knowledge obtained by this study is useful for further fractionation and structural characterization as well as the interpretation of the bioactivity differences between the various fucoidans.
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Affiliation(s)
- Sandesh Neupane
- Pharmaceutical Institute, Department of Pharmaceutical Biology, Kiel University, Gutenbergstr. 76, D- 24118 Kiel, Germany.
| | - Kaya Saskia Bittkau
- Pharmaceutical Institute, Department of Pharmaceutical Biology, Kiel University, Gutenbergstr. 76, D- 24118 Kiel, Germany.
| | - Susanne Alban
- Pharmaceutical Institute, Department of Pharmaceutical Biology, Kiel University, Gutenbergstr. 76, D- 24118 Kiel, Germany.
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15
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Mattonai M, Pawcenis D, Del Seppia S, Łojewska J, Ribechini E. Effect of ball-milling on crystallinity index, degree of polymerization and thermal stability of cellulose. BIORESOURCE TECHNOLOGY 2018; 270:270-277. [PMID: 30223158 DOI: 10.1016/j.biortech.2018.09.029] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 09/04/2018] [Accepted: 09/05/2018] [Indexed: 06/08/2023]
Abstract
A combined study of crystallinity index (CI), degree of polymerisation (DP) and thermal stability of cellulose was carried out for monitoring the effect of ball-milling. DP and CI are two fundamental quantities that describe the physico-chemical behaviour of cellulose. Milling is a common strategy to reduce cellulose crystallinity. In this work, four different commercially available celluloses were milled at 30, 60 and 120 min, and the changes in DP and CI were monitored using spectroscopic, diffraction and chromatographic techniques. Evolved gas analysis-mass spectrometry (EGA-MS) was also used to evaluate the changes in apparent activation energy (Ea) of the pyrolysis reaction upon different milling times by using model-free isoconversional methods. The results showed substantial decrease in CI values and moderate changes in DP after two-hours of ball-milling. Ea were found in the range 110-140 kJ/mol, and were reduced by 10% on average after two hours of ball-milling.
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Affiliation(s)
- Marco Mattonai
- Department of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy
| | - Dominika Pawcenis
- Department of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kraków, Poland
| | - Serena Del Seppia
- Department of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy
| | - Joanna Łojewska
- Department of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kraków, Poland
| | - Erika Ribechini
- Department of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy.
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16
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Barthet C, Wilson J, Cadix A, Destarac M, Chassenieux C, Harrisson S. Micellar RAFT/MADIX Polymerization. ACS Macro Lett 2017; 6:1342-1346. [PMID: 35650814 DOI: 10.1021/acsmacrolett.7b00791] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We apply the RAFT/MADIX technique to the micellar copolymerization of acrylamide and 2-acrylamido-2-methylpropanesulfonic acid sodium salt with a hydrophobic monomer, 4-tert-butylstyrene. The resulting polymers have well-controlled molecular weight distributions. In the presence of sodium dodecyl sulfate, the polymerization is better controlled by an oligo-acrylamide chain transfer agent (PAm7-XA1) than by Rhodixan A1. The associative character of the polymer is maintained under RAFT polymerization conditions and chains can be extended to form block copolymers with associative segments.
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Affiliation(s)
- Cécile Barthet
- Laboratoire
des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex 9, France
- Le Mans Université, Institut des Molécules
et Matériaux du Mans (IMMM) UMR 6283, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France
| | - James Wilson
- Solvay Novecare,
Research and Innovation Centre − Paris, 93306 Aubervilliers, France
| | - Arnaud Cadix
- Solvay Novecare,
Research and Innovation Centre − Paris, 93306 Aubervilliers, France
| | - Mathias Destarac
- Laboratoire
des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex 9, France
| | - Christophe Chassenieux
- Le Mans Université, Institut des Molécules
et Matériaux du Mans (IMMM) UMR 6283, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France
| | - Simon Harrisson
- Laboratoire
des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex 9, France
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17
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Toward ideal separation by size-exclusion chromatography. J Chromatogr A 2017; 1487:139-146. [DOI: 10.1016/j.chroma.2017.01.038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 01/11/2017] [Accepted: 01/14/2017] [Indexed: 11/19/2022]
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18
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Zielke C, Teixeira C, Ding H, Cui S, Nyman M, Nilsson L. Analysis of β-glucan molar mass from barley malt and brewer’s spent grain with asymmetric flow field-flow fractionation (AF4) and their association to proteins. Carbohydr Polym 2017; 157:541-549. [DOI: 10.1016/j.carbpol.2016.10.045] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 10/06/2016] [Accepted: 10/15/2016] [Indexed: 11/16/2022]
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