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Quezada GR, Retamal F, Jeldres M, Jeldres RI. Understanding the Behavior of Sodium Polyacrylate in Suspensions of Silica and Monovalent Salts. Polymers (Basel) 2023; 15:3861. [PMID: 37835908 PMCID: PMC10575086 DOI: 10.3390/polym15193861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 09/17/2023] [Accepted: 09/18/2023] [Indexed: 10/15/2023] Open
Abstract
This study investigated the interaction of monovalent cations with different sizes on quartz surfaces and the rheological impact that this causes in concentrated suspensions when subjected to the action of a rheological modifier, in this case, sodium polyacrylate (NaPA). Yield stress was determined using a rheometer with a vane-in-cup configuration to establish the relationship between shear stress and strain. Experiments were carried out in LiCl, NaCl, KCl, and CsCl solutions. The results show that the yield stress increases following the order Li < Na < K < Cs in the absence of PAA. However, the addition of NaPA significantly reduced the yield stress in all cases. This reduction was more noticeable in the LiCl and NaCl solutions than in the KCl and CsCl solutions, suggesting a more pronounced effect of PA in maker salts. We conducted molecular dynamics simulations to understand how PA interacts with dissolved salts on the quartz surface. Our results showed that Li had the highest adsorption, followed by Na, K, and Cs. As the salt concentration increased, so did the adsorption. We validated these simulation results with rheological experiments, which helped us understand the observed differences. The molecular interactions indicate that, in the lithium system, cationic bridges and the synergy between hydrogen bridges and hydrophobic bridges predominate mainly. This tendency decreases as the type of cation is changed due to the decrease in the electrical density of the cation in the following order: Li < Na < K < Cs. This reduces bridging with the quartz surface and, therefore, directly impacts the system's rheological properties.
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Affiliation(s)
- Gonzalo R. Quezada
- Escuela de Ingeniería Civil Química, Facultad de Ingeniería, Universidad del Bío-Bío, Concepción 4030000, Chile;
| | - Francisco Retamal
- Escuela de Ingeniería Civil Química, Facultad de Ingeniería, Universidad del Bío-Bío, Concepción 4030000, Chile;
| | - Matías Jeldres
- Departamento de Ingeniería Química y Procesos de Minerales, Facultad de Ingeniería, Universidad de Antofagasta, Antofagasta 1240000, Chile; (M.J.); (R.I.J.)
| | - Ricardo I. Jeldres
- Departamento de Ingeniería Química y Procesos de Minerales, Facultad de Ingeniería, Universidad de Antofagasta, Antofagasta 1240000, Chile; (M.J.); (R.I.J.)
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2
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McCann KB, Van Alstine J, Martinez J, Shanagar J, Bertolini J. Polyacrylic acid based plasma fractionation for the production of albumin and IgG: Compatibility with existing commercial downstream processes. Biotechnol Bioeng 2020; 117:1072-1081. [PMID: 31930475 DOI: 10.1002/bit.27265] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 12/11/2019] [Accepted: 01/06/2020] [Indexed: 11/08/2022]
Abstract
Commercial fractionation of human plasma into immunoglobulin- and albumin-rich fractions is often initiated with sequential cold ethanol-based precipitation methods, which have changed little over the past 70 years. The required low temperature (-4 to -8°C) and high concentrations of ethanol 8-40%) necessitate large-scale fixed processing lines, and major capital investment and operating costs. The resulting fractions are then further purified by ethanol based precipitation or chromatographic procedures to obtain the purified final product. Aqueous polyacrylic acid (PAA) based precipitation, which readily interfaces with existing downstream processing, could offer advantages with respect to cost, safety, environmental impact, and flexibility. Sequential precipitation with 7%, 12%, and 20% (w/v) solutions of PAA 8000 in the presence of a kosmotropic salt (sodium citrate) gave fibrinogen-, immunoglobulin-, and albumin-rich fractions with 80-90% yield and 64%, 55%, and 82% purity, respectively. Further purification of the IgG-rich precipitate by caprylic acid precipitation and anion exchange chromatography, achieved a target purity of >99%. This was also achieved for the downstream processing of the albumin-rich precipitate using a two-step ion exchange chromatographic procedure. This work shows that PAA precipitation can be used in place of cold ethanol precipitation to generate crude IgG and albumin fractions which can be purified to final products of acceptable purity.
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Affiliation(s)
- Karl B McCann
- Plasma Product Development Department, CSL Behring (Australia) Pty. Ltd., Broadmeadows, Australia
| | - James Van Alstine
- JMVA Biotech AB, Stockholm, Sweden.,Division of Bioprocess Technology, School of Biotechnology, Royal Institute of Technology, Stockholm, Sweden
| | - Jose Martinez
- Plasma Product Development Department, CSL Behring (Australia) Pty. Ltd., Broadmeadows, Australia
| | | | - Joseph Bertolini
- Plasma Product Development Department, CSL Behring (Australia) Pty. Ltd., Broadmeadows, Australia
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Gao S, Holkar A, Srivastava S. Protein-Polyelectrolyte Complexes and Micellar Assemblies. Polymers (Basel) 2019; 11:E1097. [PMID: 31261765 PMCID: PMC6680422 DOI: 10.3390/polym11071097] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 06/20/2019] [Accepted: 06/24/2019] [Indexed: 12/18/2022] Open
Abstract
In this review, we highlight the recent progress in our understanding of the structure, properties and applications of protein-polyelectrolyte complexes in both bulk and micellar assemblies. Protein-polyelectrolyte complexes form the basis of the genetic code, enable facile protein purification, and have emerged as enterprising candidates for simulating protocellular environments and as efficient enzymatic bioreactors. Such complexes undergo self-assembly in bulk due to a combined influence of electrostatic interactions and entropy gains from counterion release. Diversifying the self-assembly by incorporation of block polyelectrolytes has further enabled fabrication of protein-polyelectrolyte complex micelles that are multifunctional carriers for therapeutic targeted delivery of proteins such as enzymes and antibodies. We discuss research efforts focused on the structure, properties and applications of protein-polyelectrolyte complexes in both bulk and micellar assemblies, along with the influences of amphoteric nature of proteins accompanying patchy distribution of charges leading to unique phenomena including multiple complexation windows and complexation on the wrong side of the isoelectric point.
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Affiliation(s)
- Shang Gao
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Advait Holkar
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Samanvaya Srivastava
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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Sieberz J, Cinar E, Wohlgemuth K, Schembecker G. Clarification of a monoclonal antibody with cationic polyelectrolytes: Analysis of influencing parameters. Biochem Eng J 2017. [DOI: 10.1016/j.bej.2017.02.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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5
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Boggione MJ, Becher R, Farruggia B. Single method of purification for endoglucanase from Aspergillus niger by polyelectrolyte precipitation. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2016. [DOI: 10.1016/j.bcab.2016.05.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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6
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Abstract
Selective precipitation of proteins can be used as a bulk method to recover the majority of proteins from a crude lysate, as a selective method to fractionate a subset of proteins from a protein solution, or as a very specific method to recover a single protein of interest from a purification step. This unit describes a number of methods suitable for selective precipitation. In each of the protocols that are outlined, the physical or chemical basis of the precipitation process, the parameters that can be varied for optimization, and the basic steps for developing an optimized precipitation are described.
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Affiliation(s)
- Daumantas Matulis
- Department of Biothermodynamics and Drug Design, Institute of Biotechnology, Vilnius University, Vilnius, Lithuania
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Rios JL, Lu G, Seo NE, Lambert T, Putnam D. Prolonged Release of Bioactive Model Proteins from Anionic Microgels Fabricated with a New Microemulsion Approach. Pharm Res 2015; 33:879-92. [PMID: 26620311 DOI: 10.1007/s11095-015-1834-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 11/20/2015] [Indexed: 11/25/2022]
Abstract
PURPOSE Therapeutic proteins have become an integral part of health care. However, their controlled delivery remains a challenge. Protein function depends on a delicate three dimensional structure, which can be damaged during the fabrication of controlled release systems. This study presents a microgel-based controlled release system capable of high loading efficiencies, prolonged release and retention of protein function. METHODS A new DMSO/Pluronic microemulsion served as a reaction template for the crosslinking of poly(acrylic acid) and oligo (ethylene glycol) to form microgels. Poly(acylic acid) molecular weights and microgel crosslinking densities were altered to make a series of microgels. Microgel capacity to capture and retain proteins of different sizes and isoelectric points, to control their release rate (over ~30 days) and to maintain the biofunctionality of the released proteins were evaluated. RESULTS Microgels of different sizes and morphologies were synthesized. Loading efficiencies of 100% were achieved with lysozyme in all formulations. The loading efficiency of all other proteins was formulation dependent. Release of lysozyme was achieved for up to 30 days and the released lysozyme retained over 90% of its activity. CONCLUSIONS High loading efficiencies and prolonged release of different proteins was achieved. Furthermore, lysozyme's functionality remained uncompromised after encapsulation and release. This work begins to lay the foundation for a broad platform for the delivery of therapeutic proteins.
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Affiliation(s)
- Jose L Rios
- Meinig School of Biomedical Engineering, Cornell University, 147 Weill Hall, Ithaca, New York, 14853, USA
| | - Gongcheng Lu
- Meinig School of Biomedical Engineering, Cornell University, 147 Weill Hall, Ithaca, New York, 14853, USA
| | - Na Eun Seo
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, New York, 14853, USA
| | - Tamara Lambert
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, New York, 14853, USA
| | - David Putnam
- Meinig School of Biomedical Engineering, Cornell University, 147 Weill Hall, Ithaca, New York, 14853, USA.
- School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York, 14853, USA.
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Singh N, Arunkumar A, Chollangi S, Tan ZG, Borys M, Li ZJ. Clarification technologies for monoclonal antibody manufacturing processes: Current state and future perspectives. Biotechnol Bioeng 2015; 113:698-716. [DOI: 10.1002/bit.25810] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 08/20/2015] [Accepted: 08/20/2015] [Indexed: 01/15/2023]
Affiliation(s)
- Nripen Singh
- Biologics Development; Global Manufacturing and Supply, Bristol-Myers Squibb; 35 South Street Hopkinton Massachusetts 01748
| | - Abhiram Arunkumar
- Biologics Development; Global Manufacturing and Supply, Bristol-Myers Squibb; 35 South Street Hopkinton Massachusetts 01748
| | - Srinivas Chollangi
- Biologics Development; Global Manufacturing and Supply, Bristol-Myers Squibb; 35 South Street Hopkinton Massachusetts 01748
| | - Zhijun George Tan
- Biologics Development; Global Manufacturing and Supply, Bristol-Myers Squibb; 35 South Street Hopkinton Massachusetts 01748
| | - Michael Borys
- Biologics Development; Global Manufacturing and Supply, Bristol-Myers Squibb; 35 South Street Hopkinton Massachusetts 01748
| | - Zheng Jian Li
- Biologics Development; Global Manufacturing and Supply, Bristol-Myers Squibb; 35 South Street Hopkinton Massachusetts 01748
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9
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Pathak J, Rawat K, Aswal VK, Bohidar HB. Interactions in globular proteins with polyampholyte: coacervation route for protein separation. RSC Adv 2015. [DOI: 10.1039/c4ra13133a] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Representative model of protein–protein separation in a BSA–GB–β-Lg aqueous solution.
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Affiliation(s)
- Jyotsana Pathak
- Polymer and Biophysics Laboratory
- School of Physical Sciences
- Jawaharlal Nehru University
- New Delhi 110067
- India
| | - Kamla Rawat
- Special Center for Nanosciences
- Jawaharlal Nehru University
- New Delhi 110067
- India
- Inter University Accelerator Centre (IUAC)
| | - V. K. Aswal
- Solid State Physics Division
- Bhabha Atomic Research Centre
- Mumbai-400085
- India
| | - H. B. Bohidar
- Polymer and Biophysics Laboratory
- School of Physical Sciences
- Jawaharlal Nehru University
- New Delhi 110067
- India
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10
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Identification of parameter interactions influencing the precipitation of a monoclonal antibody with anionic polyelectrolytes. Sep Purif Technol 2014. [DOI: 10.1016/j.seppur.2014.02.033] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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11
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Marini A, Imelio N, Marini S, Romanini D, Farruggia B. Extraction of lipase from Aspergillus niger by insoluble complex formation with anionic and cationic polyelectrolytes. Process Biochem 2012. [DOI: 10.1016/j.procbio.2012.08.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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12
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13
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Zheng Y, Wang X, Ji Y. Monoliths with proteins as chiral selectors for enantiomer separation. Talanta 2012; 91:7-17. [DOI: 10.1016/j.talanta.2012.01.039] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 01/15/2012] [Accepted: 01/18/2012] [Indexed: 12/25/2022]
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14
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A novel biopesticide production: attagel-mediated precipitation of chitinase from Beauveria bassiana SFB-205 supernatant for thermotolerance. Appl Microbiol Biotechnol 2010; 87:1639-48. [DOI: 10.1007/s00253-010-2543-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Revised: 03/01/2010] [Accepted: 03/04/2010] [Indexed: 11/27/2022]
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15
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Fan Y, Wang Y, Fan Y, Ma J. Potentiometric studies on the interaction between superoxide dismutase and hyaluronic acid. J Appl Polym Sci 2009. [DOI: 10.1002/app.30238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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16
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Abstract
Selective precipitation of proteins can be used as a bulk method to recover the majority of proteins from a crude lysate, as a selective method to fractionate a subset of proteins from a protein solution, or as a very specific method to recover a single protein of interest from a purification step. This unit describes a number of methods suitable for selective precipitation. In each of the protocols that are outlined, the physical or chemical basis of the precipitation process, the parameters that can be varied for optimization, and the basic steps for developing an optimized precipitation are described.
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Affiliation(s)
- R E Lovrien
- University of Minnesota, St. Paul, Minnesota, USA
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17
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Ni R, Cao D, Wang W. Release of Lysozyme from the Branched Polyelectrolyte−Lysozyme Complexation. J Phys Chem B 2008; 112:4393-400. [DOI: 10.1021/jp076348z] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ran Ni
- Division of Molecular and Materials Simulation, Key Lab for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China
| | - Dapeng Cao
- Division of Molecular and Materials Simulation, Key Lab for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China
| | - Wenchuan Wang
- Division of Molecular and Materials Simulation, Key Lab for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China
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18
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Bergmann NM, Peppas NA. Molecularly imprinted polymers with specific recognition for macromolecules and proteins. Prog Polym Sci 2008. [DOI: 10.1016/j.progpolymsci.2007.09.004] [Citation(s) in RCA: 139] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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19
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Topuzoğulları M, Çimen NS, Mustafaeva Z, Mustafaev M. Molecular-weight distribution and structural transformation in water-soluble complexes of poly(acrylic acid) and bovine serum albumin. Eur Polym J 2007. [DOI: 10.1016/j.eurpolymj.2007.04.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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20
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Holler C, Vaughan D, Zhang C. Polyethyleneimine precipitation versus anion exchange chromatography in fractionating recombinant beta-glucuronidase from transgenic tobacco extract. J Chromatogr A 2007; 1142:98-105. [PMID: 16950325 DOI: 10.1016/j.chroma.2006.08.044] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2006] [Revised: 08/11/2006] [Accepted: 08/15/2006] [Indexed: 11/16/2022]
Abstract
Tobacco has been studied as a possible host for the production of recombinant proteins. In this report, recombinant beta-glucuronidase (rGUS) was used as a model protein to study the feasibility of using polyethyleneimine (PEI) precipitation to fractionate acidic recombinant proteins from transgenic tobacco. Results showed that rGUS was preferentially precipitated when the PEI dosage was beyond 200mg PEI/g total protein. At 700-800 mg PEI/g total protein, nearly 100% rGUS was precipitated with less than 40% native tobacco proteins co-precipitated. Approximately 85-90% of the rGUS activity could be recovered from the precipitation pellet for an enrichment ratio of 2.7-3.4. As a comparison, anion exchange chromatography (AEX) yielded similar results to PEI precipitation with 66-90% rGUS activity recovered and an enrichment ratio of 1.8-3.1. The rGUS was further purified by an additional hydrophobic interaction chromatographic (HIC) step after precipitation or AEX. Similar results in terms of rGUS activity recovered and enrichment were obtained. The major interfering protein at the end of all purification steps is most likely the Fraction 1 protein ribulose 1,5-bisphosphate carboxylase-oxygenase (Rubisco). The presence of this protein is likely the cause for the varying and somewhat low enrichment ratios, but it may be later removed via a size-exclusion chromatography step. PEI precipitation offers the advantage of allowing significant sample concentration prior to subsequent purification techniques such as chromatography and is much less expensive than chromatographic methods as well. Through direct comparison, this study shows that PEI may be used as an initial fractionation step in replacement of AEX to facilitate the purification of acidic recombinant proteins from transgenic tobacco.
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Affiliation(s)
- Chris Holler
- Department of Biological Systems Engineering, 210 Seitz Hall, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
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21
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Dubin PL, Gao J, Mattison K. Protein Purification by Selective Phase Separation with Polyelectrolytes. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/03602549408001288] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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22
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Cooper C, Dubin P, Kayitmazer A, Turksen S. Polyelectrolyte–protein complexes. Curr Opin Colloid Interface Sci 2005. [DOI: 10.1016/j.cocis.2005.05.007] [Citation(s) in RCA: 552] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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23
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Zhang C, Lillie R, Cotter J, Vaughan D. Lysozyme purification from tobacco extract by polyelectrolyte precipitation. J Chromatogr A 2005; 1069:107-12. [PMID: 15844488 DOI: 10.1016/j.chroma.2004.10.018] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Tobacco is widely used as a model plant for feasibility studies of recombinant protein production from transgenic plants. However, dealing with large quantities of biomass to recover recombinant proteins is a challenge for down-stream processing. In this study, the effect of isoelectric precipitation on native tobacco protein was first studied. Among the three acids studied, hydrochloric acid is shown to be more effective than acetic or citric acid, and at pH 4, 60% of native tobacco protein was precipitated by HCl. Egg white lysozyme was used as the model protein to test the feasibility of polyelectrolyte precipitation in protein recovery from tobacco extract. Precipitation of lysozyme at pH 7 was shown ineffective probably because of the interference of polyphenolic acids. However, after isoelectric precipitation at pH 5 poly(acrylic) acid (PAA) was shown to precipitate 85% of the soluble lysozyme when the polymer dosage was increased to 1.5 mg polymer/mg lysozyme, while negligible amounts of native tobacco protein was co-precipitated. Lysozyme precipitation by PAA in tobacco extract obtained at pH 5 was also studied, and lysozyme yield was significant improved.
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Affiliation(s)
- Chenming Zhang
- Department of Biological Systems Engineering, Virginia Polytechnic Institute and State University, 210 Seitz Hall, Blacksburg, VA 24061, USA.
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24
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Sharma VK, Kalonia DS. Polyethylene glycol-induced precipitation of interferon alpha-2a followed by vacuum drying: development of a novel process for obtaining a dry, stable powder. AAPS PHARMSCI 2004; 6:E4. [PMID: 15198505 PMCID: PMC2750939 DOI: 10.1208/ps060104] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2003] [Accepted: 12/30/2003] [Indexed: 12/29/2022]
Abstract
Feasibility studies were performed on the development of a novel process based on polyethylene glycol (PEG)-induced precipitation of proteins followed by vacuum drying in the presence of sugars to obtain dry protein powders. Apparent solubility of interferon alpha-2a (IFNalpha2a) was determined in the presence of various PEGs and the effect of solution pH, ionic strength, and temperature was investigated. IFNalpha2a precipitate was dried at a shelf temperature of 25 degrees C at 100 mTorr either as it is or in the presence of mannitol and/or trehalose. The dried IFNalpha2a formulations were subjected to accelerated stability studies at 40 degrees C (3 months), and the stability was compared with that of a similar lyophilized formulation. The results indicated that more than 90% of the protein could be precipitated using 10% wt/vol PEG 1450 at pH 6.5 at a solution ionic strength of 71 mM. Vacuum drying of the precipitate only resulted in the formation of insoluble aggregates of IFNalpha2a; however, this was prevented by the addition of either mannitol or trehalose. The addition of excess mannitol resulted in low residual moisture content and better handling of the final dried product. Accelerated storage stability did not show any aggregation and showed less than 5% formation of oxidized IFNalpha2a in the dried formulation containing IFNalpha2a:trehalose:mannitol in a 1:10:100 wt/wt ratio upon storage at 40 degrees C for 3 months. The stability of this vacuum dried formulation was comparable with that of a similar lyophilized formulation.
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Affiliation(s)
- Vikas K. Sharma
- />Department of Pharmaceutical Sciences, University of Connecticut, 06269 Storrs, CT
- />Biotechnology Process Engineering Center, and Department of Chemistry, Massachusetts Institute of Technology, 02139 Cambridge, MA
| | - Devendra S. Kalonia
- />Department of Pharmaceutical Sciences, University of Connecticut, 06269 Storrs, CT
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25
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Persson J, Lester P. Purification of antibody and antibody-fragment fromE. coli homogenate using 6,9-diamino-2-ethoxyacridine lactate as precipitation agent. Biotechnol Bioeng 2004; 87:424-34. [PMID: 15281116 DOI: 10.1002/bit.20126] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
To obtain a more efficient purification process for antibody fragments from an Escherichia coli homogenate, the precipitant, Ethodin (6,9-diamino-2-ethoxyacridine lactate) was introduced to the homogenate. By adding the precipitant a drastic reduction of host cell protein was obtained. The majority of the proteins were recovered in a precipitate with the cell debris, while the antibody or antibody-fragment was recovered in the clarified supernatant. In addition, DNA was also efficiently precipitated when using Ethodin as a precipitation agent. The improved purity of the clarified extract obtained by using the precipitant allows for the use of smaller chromatography columns and may reduce the number of chromatographic steps required in the recovery process. The effect of Ethodin concentration, pH, temperature, and conductivity were investigated. The investigation was performed on two different antibody-fragments, e.g., F(ab')(2) molecules and a full-length antibody produced in E. coli. The two F(ab')(2) proteins were F(ab')(2)A and F(ab')(2)B, which have a similar molecular mass (100 kDa) but different isoelectric points (pIs), i.e., 8.9 and 7.5, respectively. The full-length antibody, Ab (the full IgG form of F(ab')(2)B) has a pI of 7.8 and molecular mass of 150 kDa. The investigation showed that the highest purification factors were obtained at neutral pH, low conductivity, and Ethodin concentrations of 0.6%.
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Grymonpré KR, Staggemeier BA, Dubin PL, Mattison KW. Identification by integrated computer modeling and light scattering studies of an electrostatic serum albumin-hyaluronic acid binding site. Biomacromolecules 2003; 2:422-9. [PMID: 11749202 DOI: 10.1021/bm005656z] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Dynamic light scattering and turbidimetry, carried out on solutions of hyaluronic acid (HA) and bovine or human serum albumin (SA) at fixed ionic strength (I), revealed a critical pH corresponding to the onset of HA-SA soluble complex formation. Subsequent reduction of pH below pH(c), corresponding to an increase in protein net positive charge, results in phase separation of the complex. The sensitivity of pH(c) to I indicated the primacy of electrostatic interactions in this process. Since pH(c) was always above the pK(a) of HA, these effects could be attributed to the influence of protein charge. The electrostatic potential around HSA was modeled using DelPhi (MSI) under pH, I conditions corresponding to incipient binding, phase separation, and noninteraction. At all incipient binding conditions (i.e., pH(c), at varying I), an identical region of positive potential 5 A from the protein van der Waals surface appeared. This unique domain intensified with a decrease in pH or I (corresponding to stronger binding), and diminished with an increase in pH or I (i.e., at noninteracting conditions). The size and low curvature of this domain could readily accommodate a 12 nm (decamer) sequence of HA. Simple electrostatic considerations indicate an electrostatic binding energy for the formation of this complex of ca. 1 kT, consistent with the condition of incipient complex formation. We suggest that such weak electrostatic binding may characterize nonspecific interactions for other protein-gylcosaminoglycan pairs.
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Affiliation(s)
- K R Grymonpré
- Department of Chemistry, Indiana University-Purdue University, Indianapolis, Indiana 46202-3276, USA
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Achilles SL, Shete PB, Whaley KJ, Moench TR, Cone RA. Microbicide efficacy and toxicity tests in a mouse model for vaginal transmission of Chlamydia trachomatis. Sex Transm Dis 2002; 29:655-64. [PMID: 12438901 DOI: 10.1097/00007435-200211000-00007] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Microbicides are being developed for woman-controlled protection against sexually transmitted diseases (STDs). GOAL The goal of the study was to test candidate microbicides in a mouse model for preventing vaginal transmission of and for acute toxicity to columnar epithelium. STUDY DESIGN Progestin-sensitized CF-1 mice were treated vaginally with 50 microl of microbicide, followed either by vaginal inoculation with 10 ID(50) of serovar D or by examination of the epithelial surface for acute toxicity with a viability stain (ethidium homodimer-1). RESULTS Nonoxynol-9 (N9), sodium dodecyl sulfate (SDS), chlorhexidine digluconate, and BufferGel all provided significant though incomplete protection against vaginal transmission. Other candidates, all of which were effective in vitro, provided no vaginal protection: kappa-carrageenan, dextran sulfate, polystyrene sulfonate, Concanavalin A, wheat germ agglutinin, and agglutinin. The surface-active agents (N9, SDS, and chlorhexidine) caused significant acute epithelial toxicity: 3 days after chlorhexidine exposure, mice also had vaginal friability and markedly increased susceptibility to. BufferGel was the only candidate tested that was both protective and relatively nontoxic. CONCLUSION Microbicides can provide vaginal protection against in highly susceptible progestin-sensitized mice. Since N9 does not inactivate, it likely protects by killing target cells in the vagina. Despite the ability to both potently inactivate and kill target cells, two surface-active agents, SDS and chlorhexidine, failed to provide complete protection, a circumstance which emphasizes the importance of distributing microbicides to all susceptible surfaces.
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Yu J, Liu HZ, Chen JY. Selective precipitation of water-soluble proteins using designed polyelectrolyte. SEP SCI TECHNOL 2002. [DOI: 10.1081/ss-120000330] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Vaidya A, Lele B, Deshmukh M, Kulkarni M. Design and evaluation of new ligands for lysozyme recovery by affinity thermoprecipitation. Chem Eng Sci 2001. [DOI: 10.1016/s0009-2509(01)00169-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Vaidya AA, Lele BS, Kulkarni MG, Mashelkar RA. Thermoprecipitation of lysozyme from egg white using copolymers of N-isopropylacrylamide and acidic monomers. J Biotechnol 2001; 87:95-107. [PMID: 11278034 DOI: 10.1016/s0168-1656(00)00382-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Thermoprecipitation of lysozyme from egg white was demonstrated using copolymers of N-isopropylacrylamide with acrylic acid, methacrylic acid, 2-acryloylamido-2-methylpropane-sulfonic acid and itaconic acid, respectively. Polymers synthesized using molar feed ratio of N-isopropylacrylamide:acidic monomers of 98:2 exhibited lower critical solution temperatures in the range of 33--35 degrees C. These polymers exhibited electrostatic interactions with lysozyme and inhibited its bacteriolytic activity. The concentration of acidic groups required to attain 50% relative inhibition of lysozyme by the polymers, was 10(4)--10(5) times lower than that required for the corresponding monomers. This was attributed to the multimeric nature of polymer-lysozyme binding. More than 90% lysozyme activity was recovered from egg white. Polymers exhibited reusability up to at least 16 cycles with retention of >85% recovery of specific activity from aqueous solution. In contrast, copolymer comprising natural inhibitor of lysozyme i.e. poly (N-isopropylacrylamide-co-O-acryloyl N-acetylglucosamine) lost 50% recovery of specific activity. Thermoprecipitation using these copolymers, which enables very high recovery of lysozyme from egg white, would be advantageous over pH sensitive polymers, which generally exhibit lower recovery.
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Affiliation(s)
- A A Vaidya
- Chemical Engineering Division, National Chemical Laboratory, Polymer Science and Engineering Group, Pune 411 008, India
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KIM WOONSOO, KIM HYUNSEOK, HIRASAWA IZUMI, KIM WOOSIK. Combination Mechanism of Lysozyme with Polyacrylic Acid at Equilibrium in Polyelectrolyte Precipitation. JOURNAL OF CHEMICAL ENGINEERING OF JAPAN 2001. [DOI: 10.1252/jcej.34.1244] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- WOON-SOO KIM
- Department of Applied Chemistry, School of Science and Engineering, Waseda University
| | - HYUN-SEOK KIM
- Department of Chemical Engineering, Institution of Materials Science and Technology, KyungHee University
| | - IZUMI HIRASAWA
- Department of Applied Chemistry, School of Science and Engineering, Waseda University
| | - WOO-SIK KIM
- Department of Chemical Engineering, Institution of Materials Science and Technology, KyungHee University
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KIM WOONSOO, KIM HYUNSEOK, HIRASAWA IZUMI, KIM WOOSIK. Prediction of Lysozyme Separation by Polyelectrolyte Precipitation in Mechanically Agitated MSMPR Reactor. JOURNAL OF CHEMICAL ENGINEERING OF JAPAN 2001. [DOI: 10.1252/jcej.34.1259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- WOON-SOO KIM
- Department of Applied Chemistry, School of Science and Engineering, Waseda University
| | - HYUN-SEOK KIM
- Department of Chemical Engineering, Institution of Materials Science and Technology, KyungHee University
| | - IZUMI HIRASAWA
- Department of Applied Chemistry, School of Science and Engineering, Waseda University
| | - WOO-SIK KIM
- Department of Chemical Engineering, Institution of Materials Science and Technology, KyungHee University
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Gao Q, Shao Z, Sun Y, Lin H, Zhou P, Yu T. Complex Formation of Silk Fibroin with Poly(acrylic acid). Polym J 2000. [DOI: 10.1295/polymj.32.269] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Borrega R, Tribet C, Audebert R. Reversible Gelation in Hydrophobic Polyelectrolyte/Protein Mixtures: An Example of Cross-Links between Soft and Hard Colloids. Macromolecules 1999. [DOI: 10.1021/ma981872c] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- R. Borrega
- Laboratoire de Physico-chimie des Polymères UMR 7615, ESPCI, CNRS, Université Paris 6, 10 rue Vauquelin, F-75231 Paris Cedex 05, France
| | - C. Tribet
- Laboratoire de Physico-chimie des Polymères UMR 7615, ESPCI, CNRS, Université Paris 6, 10 rue Vauquelin, F-75231 Paris Cedex 05, France
| | - R. Audebert
- Laboratoire de Physico-chimie des Polymères UMR 7615, ESPCI, CNRS, Université Paris 6, 10 rue Vauquelin, F-75231 Paris Cedex 05, France
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Xia J, Dubin PL, Kokufuta E, Havel H, Muhoberac BB. Light scattering, CD, and ligand binding studies of ferrihemoglobin-polyelectrolyte complexes. Biopolymers 1999; 50:153-61. [PMID: 10380339 DOI: 10.1002/(sici)1097-0282(199908)50:2<153::aid-bip4>3.0.co;2-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Quasi-elastic light scattering (QELS), electrophoretic light scattering (ELS), CD spectroscopy, and azide binding titrations were used to study the complexation at pH 6.8 between ferrihemoglobin and three polyelectrolytes that varied in charge density and sign. Both QELS and ELS show that the structure of the soluble complex formed between ferrihemoglobin and poly(diallyldimethylammonium chloride) [PDADMAC] varies with protein concentration. At fixed 1.0 mg/mL polyelectrolyte concentration, protein addition increases complex size and decreases complex mobility in a tightly correlated manner. At 1.0 mg/mL of greater protein concentration, a stable complex is formed between one polyelectrolyte chain and many protein molecules (i.e., an intrapolymer complex) with apparent diameter approximately 2.5 times that of the protein-free polyelectrolyte. Under conditions of excess polyelectrolyte, each of the three ferrihemoglobin-polyelectrolyte solutions exhibits a single diffusion mode in QELS, which indicates that all protein molecules are complexed. CD spectra suggest little or no structural disruption of ferrihemoglobin upon complexation. Azide binding to the ferrihemoglobin-poly(2-acrylamide-2-methylpropanesulfonate) [PAMPS] complex is substantially altered relative to the polyelectrolyte-free protein, but minimal change in induced by complexation with an AMPS-based copolymer of reduced linear charge density. The change in azide binding induced by PDADMAC is intermediate between that of PAMPS and its copolymer.
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Affiliation(s)
- J Xia
- Department of Chemistry, Indiana University-Purdue University, Indianapolis 46202, USA
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Li M, Wu C. Self-Association of Poly(N-isopropylacrylamide) and Its Complexation with Gelatin in Aqueous Solution. Macromolecules 1999. [DOI: 10.1021/ma990085s] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mei Li
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong, and The Open Laboratory for Bond Selective Chemistry, Department of Chemical Physics, University of Science & Technology of China, Hefei, Anhui, China
| | - Chi Wu
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong, and The Open Laboratory for Bond Selective Chemistry, Department of Chemical Physics, University of Science & Technology of China, Hefei, Anhui, China
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Jiang J, Prausnitz JM. Molecular Thermodynamics for Protein Precipitation with a Polyelectrolyte. J Phys Chem B 1999. [DOI: 10.1021/jp990455e] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jianwen Jiang
- Chemical Engineering Department, University of California, Berkeley, and Chemical Sciences Division, Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720
| | - John M. Prausnitz
- Chemical Engineering Department, University of California, Berkeley, and Chemical Sciences Division, Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720
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Li Y, Mattison KW, Dubin PL, Havel HA, Edwards SL. Light scattering studies of the binding of bovine serum albumin to a cationic polyelectrolyte. Biopolymers 1998. [DOI: 10.1002/(sici)1097-0282(199604)38:4<527::aid-bip8>3.0.co;2-v] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Yoshida K, Sokhakian S, Dubin PL. Binding of Polycarboxylic Acids to Cationic Mixed Micelles: Effects of Polymer Counterion Binding and Polyion Charge Distribution. J Colloid Interface Sci 1998; 205:257-264. [PMID: 9735188 DOI: 10.1006/jcis.1998.5618] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mixed micelles of cetyltrimethylammonium chloride (CTAC) and n-dodecyl hexaoxyethylene glycol monoether (C12E8) bind to polyanions when the mole fraction of the cationic surfactant exceeds a critical value (Yc). Yc corresponds to a critical micelle surface charge density at which polyelectrolyte will bind to this colloidal particle. Turbidimetric titrations were used to determine Yc for such cationic-nonionic micelles in the presence of acrylic acid and acrylamido-2-methylpropane sulfonate homopolymers (PAA and PAMPS, respectively) and their copolymers with acrylamide, as function of pH, ionic strength, and polyelectrolyte counterion. In 0.20 M NaCl, Yc for PAA is found to be remarkably insensitive to pH, i.e., virtually independent of the apparent polymer charge density xiapp. On the other hand, the expected inverse relationship between Yc and xiapp is observed either for PAA when NaCl is replaced by TMACl (tetramethylammonium chloride), or when xiapp is manipulated using acrylic acid/acrylamide copolymers at high pH. The effective charge density of PAA is thus seen to be suppressed by specific sodium ion binding, indicating that the influence of salts on the interaction of polycarboxylic acids with colloidal particles may differ qualitatively from their effect on the analogous behavior of strong polyanions. Comparisons between homo- and copolymers of acrylic acid were carried out also to test the hypothesis that the "mobility" of charges on PAA at moderate pH (degree of ionization less than unity) could make this "annealed" polymer exhibit the behavior of a more highly charged one. The results, while consistent with this expectation, were obscured by the likely effect of copolymer sequence distributions. Copyright 1998 Academic Press.
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Affiliation(s)
- K Yoshida
- Department of Chemistry, Indiana-Purdue University, Indianapolis, Indiana, 46202
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Sato T, Kamachi M, Mizusaki M, Yoda K, Morishima Y. Binding of Lysozyme to Unimolecular Micelles Formed from Hydrophobically-Modified Polyelectrolytes. Macromolecules 1998. [DOI: 10.1021/ma980784p] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Takeshi Sato
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Mikiharu Kamachi
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Masanobu Mizusaki
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Kenjiro Yoda
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Yotaro Morishima
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
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Xia J, Mattison K, Romano V, Dubin PL, Muhoberac BB. Complexation of trypsin and alcohol dehydrogenase with poly(diallyldimethylammonium chloride). Biopolymers 1997. [DOI: 10.1002/(sici)1097-0282(19970405)41:4<359::aid-bip1>3.0.co;2-l] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Petit F, Audebert R, Iliopoulos I. Interactions of hydrophobically modified poly(sodium acrylate) with globular proteins. Colloid Polym Sci 1995. [DOI: 10.1007/bf00658756] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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45
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Patrickios CS, Hertler WR, Hatton TA. Protein complexation with acrylic polyampholytes. Biotechnol Bioeng 1994; 44:1031-9. [DOI: 10.1002/bit.260440903] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Chromatographic evaluation of the binding of lysozyme to poly(dimethyldiallylammonium chloride). J Chromatogr A 1994. [DOI: 10.1016/0021-9673(94)89081-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Izumi T, Hirata M, Takahashi K, Kokufuta E. Complexation of Papain with Strong Polyanions and Enzymatic Activities of the Resulting Complexes. JOURNAL OF MACROMOLECULAR SCIENCE PART A-PURE AND APPLIED CHEMISTRY 1994. [DOI: 10.1080/10601329409349716] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Agerkvistm I, Eriksson LB. SELECTIVE FLOCCULATION WITH CHITOSAN IN E. COLI DISINTEGRATES: EFFECTS OF IONIC STRENGTH AND MULTIVALENT METAL IONS. J DISPER SCI TECHNOL 1993. [DOI: 10.1080/01932699308943404] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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49
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Chen W, Walker S, John C B. The mechanism of floc formation in protein precipitation by polyelectrolytes. Chem Eng Sci 1992. [DOI: 10.1016/0009-2509(92)80230-a] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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