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Gochev GG, Campbell RA, Schneck E, Zawala J, Warszynski P. Exploring proteins at soft interfaces and in thin liquid films - From classical methods to advanced applications of reflectometry. Adv Colloid Interface Sci 2024; 329:103187. [PMID: 38788307 DOI: 10.1016/j.cis.2024.103187] [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: 03/13/2024] [Revised: 05/12/2024] [Accepted: 05/12/2024] [Indexed: 05/26/2024]
Abstract
The history of the topic of proteins at soft interfaces dates back to the 19th century, and until the present day, it has continuously attracted great scientific interest. A multitude of experimental methods and theoretical approaches have been developed to serve the research progress in this large domain of colloid and interface science, including the area of soft colloids such as foams and emulsions. From classical methods like surface tension adsorption isotherms, surface pressure-area measurements for spread layers, and surface rheology probing the dynamics of adsorption, nowadays, advanced surface-sensitive techniques based on spectroscopy, microscopy, and the reflection of light, X-rays and neutrons at liquid/fluid interfaces offers important complementary sources of information. Apart from the fundamental characteristics of protein adsorption layers, i.e., surface tension and surface excess, the nanoscale structure of such layers and the interfacial protein conformations and morphologies are of pivotal importance for extending the depth of understanding on the topic. In this review article, we provide an extensive overview of the application of three methods, namely, ellipsometry, X-ray reflectometry and neutron reflectometry, for adsorption and structural studies on proteins at water/air and water/oil interfaces. The main attention is placed on the development of experimental approaches and on a discussion of the relevant achievements in terms of notable experimental results. We have attempted to cover the whole history of protein studies with these techniques, and thus, we believe the review should serve as a valuable reference to fuel ideas for a wide spectrum of researchers in different scientific fields where proteins at soft interface may be of relevance.
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Affiliation(s)
- Georgi G Gochev
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, 30239 Krakow, Poland; Institute of Physical Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria.
| | - Richard A Campbell
- Division of Pharmacy and Optometry, University of Manchester, M13 9PT Manchester, UK
| | - Emanuel Schneck
- Physics Department, Technical University Darmstadt, 64289 Darmstadt, Germany
| | - Jan Zawala
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, 30239 Krakow, Poland
| | - Piotr Warszynski
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, 30239 Krakow, Poland
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2
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Kurapati R, Natarajan U. New insights into adsorption structure and hydration of polymer at oil-water interface obtained by molecular dynamics simulations: Isotactic poly(methacrylic acid). POLYMER 2022. [DOI: 10.1016/j.polymer.2022.125378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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3
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Tundisi LL, Yang R, Borelli LPP, Alves T, Mehta M, Chaud MV, Mazzola PG, Kohane DS. Enhancement of the Mechanical and Drug-Releasing Properties of Poloxamer 407 Hydrogels with Casein. Pharm Res 2021; 38:515-522. [PMID: 33638121 PMCID: PMC8006178 DOI: 10.1007/s11095-021-03017-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 02/15/2021] [Indexed: 02/03/2023]
Abstract
PURPOSE Topical therapy of local disease (e.g. skin) is advantageous over oral therapy since there is less systemic drug distribution (so fewer side-effects), no first-pass effect, etc. However, patient compliance with topical therapy can be poor as it may require many applications a day and can last months. Here we propose a topical controlled release formulation with thermoresponsive gelation at body temperature and improved adhesiveness, making it easier to remain in contact with the body. METHODS The formulation contains two excipients, poloxamer 407 (P407) and casein. Casein can modify the properties of the hydrogel through molecular entanglement. In addition, tissue reaction and drug release profile were evaluated. RESULTS Changes in casein concentration affected adhesive strength, viscosity, mechanical properties and drug release, presumably by hydrophobic interactions between casein and P407. Two different concentrations of P407 were tested with two different concentrations of casein. Formulations containing 5% and 10% casein released 80% of model drug in 48 h, while formulations without casein released the same fraction in around 24 h hours. Formulations with 10% casein had almost twice the adhesive strength of those without casein. CONCLUSIONS Addition of casein modified the mechanical properties and drug release rate of the hydrogel. There was no inflammation or injury after brief exposure in vivo.
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Affiliation(s)
- Louise Lacalendola Tundisi
- Laboratory for Biomaterials and Drug Delivery, Department of Anesthesiology, Division of Critical Care Medicine, Boston Children's Hospital, Harvard Medical School, Harvard Institutes of Medicine - 4 Blackfan Circle, Room 914, Boston, MA, zip code 02115, USA
- Graduate Program in Pharmaceutical Sciences, Faculty of Pharmaceutical Sciences, University of Campinas, Campinas, SP, Brazil
| | - Rong Yang
- Laboratory for Biomaterials and Drug Delivery, Department of Anesthesiology, Division of Critical Care Medicine, Boston Children's Hospital, Harvard Medical School, Harvard Institutes of Medicine - 4 Blackfan Circle, Room 914, Boston, MA, zip code 02115, USA
| | | | - Thais Alves
- LaBNUS - Biomaterials and Nanotechnology Laboratory, University of Sorocaba, Sorocaba, SP, Brazil
| | - Manisha Mehta
- Laboratory for Biomaterials and Drug Delivery, Department of Anesthesiology, Division of Critical Care Medicine, Boston Children's Hospital, Harvard Medical School, Harvard Institutes of Medicine - 4 Blackfan Circle, Room 914, Boston, MA, zip code 02115, USA
| | - Marco Vinícius Chaud
- LaBNUS - Biomaterials and Nanotechnology Laboratory, University of Sorocaba, Sorocaba, SP, Brazil
| | - Priscila Gava Mazzola
- Faculty of Pharmaceutical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Daniel S Kohane
- Laboratory for Biomaterials and Drug Delivery, Department of Anesthesiology, Division of Critical Care Medicine, Boston Children's Hospital, Harvard Medical School, Harvard Institutes of Medicine - 4 Blackfan Circle, Room 914, Boston, MA, zip code 02115, USA.
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4
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Trégouët C, Salez T, Pantoustier N, Perrin P, Reyssat M, Monteux C. Probing the adsorption/desorption of amphiphilic polymers at the air-water interface during large interfacial deformations. SOFT MATTER 2019; 15:6200-6206. [PMID: 31328760 DOI: 10.1039/c9sm00368a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Hydrophobically modified polymers are good candidates for the stabilization of liquid interfaces thanks to the high anchoring energy of the hydrophobic parts. In this article we probe the interfacial anchoring of a series of home-made hydrophobically modified polymers with controlled degree of grafting by studying their behavior upon large area dilations and compressions. By comparing the measured interfacial tension to the one that we expect in the case of a constant number of adsorbed monomers, we are able to deduce whether desorption or adsorption occurs during area variations. We find that the polymer chains with the longest hydrophobic grafts desorb at larger compressions compared to the polymers with the shortest grafts, because of their larger desorption energy. Furthermore, for a given graft length, we observe more desorption for polymers with the highest grafting densities. We attribute this counter intuitive result to the fact that at high grafting densities, the length of the polymer loops is shorter, and hence the elastic penalty upon compression is larger for these layers, leading to a faster desorption. Comparing the elastic penalty to thermal energy, kBT, enables deducing a critical grafting density above which desorption of grafts is expected upon compression, which is consistent with our experimental results. In the case of large area dilations, the experiments reveal that the number of adsorbed anchors remains constant in the case of chains with a low grafting density while chains with the highest degree of grafting seem to show some degree of adsorption during the dilatation. Therefore, in these highly grafted chains there may be unadsorbed grafts remaining in the vicinity of the interface, which may adsorb quickly at the interface upon dilatation.
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Affiliation(s)
- C Trégouët
- Laboratoire Sciences et Ingénierie de la Matière Molle, PSL Research University, Sorbonne University, ESPCI Paris, UMR 7615 CNRS, 10 rue Vauquelin, 75231 Paris cedex 05, France and UMR CNRS Gulliver 7083, ESPCI Paris, PSL Research University, 75005 Paris, France
| | - T Salez
- Univ. Bordeaux, CNRS, LOMA, UMR 5798, F-33405 Talence, France and Global Station for Soft Matter, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, Hokkaido 060-0808, Japan.
| | - N Pantoustier
- Laboratoire Sciences et Ingénierie de la Matière Molle, PSL Research University, Sorbonne University, ESPCI Paris, UMR 7615 CNRS, 10 rue Vauquelin, 75231 Paris cedex 05, France
| | - P Perrin
- Laboratoire Sciences et Ingénierie de la Matière Molle, PSL Research University, Sorbonne University, ESPCI Paris, UMR 7615 CNRS, 10 rue Vauquelin, 75231 Paris cedex 05, France
| | - M Reyssat
- UMR CNRS Gulliver 7083, ESPCI Paris, PSL Research University, 75005 Paris, France
| | - C Monteux
- Laboratoire Sciences et Ingénierie de la Matière Molle, PSL Research University, Sorbonne University, ESPCI Paris, UMR 7615 CNRS, 10 rue Vauquelin, 75231 Paris cedex 05, France and Global Station for Soft Matter, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, Hokkaido 060-0808, Japan.
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5
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Gong H, Xu L, Xu G, Zhu T, Dong M. Effects of Sodium Benzoate and Sodium Chloride on the Aggregation Behaviors of PEO‐PPO‐ph‐PPO‐PEO and PPO‐PEO‐ph‐PEO‐PPO at the Air/Water Interface. J SURFACTANTS DETERG 2018. [DOI: 10.1002/jsde.12213] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Houjian Gong
- School of Petroleum Engineering China University of Petroleum (East China) Qingdao, 266580 P. R. China
- Key Laboratory of Colloid and Interface Chemistry Shandong University, Ministry of Education, Shandong University Jinan, 250100 P. R. China
| | - Long Xu
- School of Petroleum Engineering China University of Petroleum (East China) Qingdao, 266580 P. R. China
| | - Guiying Xu
- Key Laboratory of Colloid and Interface Chemistry Shandong University, Ministry of Education, Shandong University Jinan, 250100 P. R. China
| | - Teng Zhu
- School of Petroleum Engineering China University of Petroleum (East China) Qingdao, 266580 P. R. China
| | - Mingzhe Dong
- School of Petroleum Engineering China University of Petroleum (East China) Qingdao, 266580 P. R. China
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Trégouët C, Mikhailovskaya A, Salez T, Pantoustier N, Perrin P, Reyssat M, Monteux C. Adsorption dynamics of hydrophobically modified polymers at an air-water interface. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2018; 41:101. [PMID: 30182262 DOI: 10.1140/epje/i2018-11711-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 08/01/2018] [Indexed: 06/08/2023]
Abstract
Using surface-tension measurements, we study the brush-limited adsorption dynamics of a range of amphiphilic polymers, PAAH-[Formula: see text]-[Formula: see text] composed of a poly(acrylic acid) backbone, PAAH, grafted with a fraction [Formula: see text] of alkyl moieties, containing either n = 8 or n = 12 carbon atoms, at pH conditions where the PAAH backbone is not charged. At short times, the surface tension decreases more sharply as the degree of grafting increases, while, at long times, the adsorption dynamics becomes logarithmic in time and is slower as the degree of grafting increases. This logarithmic behavior at long times indicates the building of a free-energy barrier which grows over time. To account for the observed surface tension evolution with the degree of grafting we propose a scenario, where the free-energy barrier results from both the deformation of the incoming polymer coils and the deformation of the adsorbed brush. Our model involves only two fitting parameters, the monomer size and the area needed for one molecule during adsorption and is in agreement with the experimental data. We obtain a reasonable value for the monomer size and find an area per adsorbed polymer chain of the order of 1 nm2, showing that the polymer chains are strongly stretched as they adsorb.
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Affiliation(s)
- C Trégouët
- Laboratoire Sciences et Ingénierie de la Matière Molle, PSL Research University, UPMC Univ Paris 06, ESPCI Paris, UMR 7615 CNRS, 10 rue Vauquelin, 75231, Paris Cedex 05, France
- UMR CNRS Gulliver 7083, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75231, Paris cedex 05, France
| | - A Mikhailovskaya
- Laboratoire Sciences et Ingénierie de la Matière Molle, PSL Research University, UPMC Univ Paris 06, ESPCI Paris, UMR 7615 CNRS, 10 rue Vauquelin, 75231, Paris Cedex 05, France
| | - T Salez
- Univ. Bordeaux, CNRS, LOMA, UMR 5798, F-33405, Talence, France
- Global Station for Soft Matter, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, 060-0808, Hokkaido, Japan
| | - N Pantoustier
- Laboratoire Sciences et Ingénierie de la Matière Molle, PSL Research University, UPMC Univ Paris 06, ESPCI Paris, UMR 7615 CNRS, 10 rue Vauquelin, 75231, Paris Cedex 05, France
| | - P Perrin
- Laboratoire Sciences et Ingénierie de la Matière Molle, PSL Research University, UPMC Univ Paris 06, ESPCI Paris, UMR 7615 CNRS, 10 rue Vauquelin, 75231, Paris Cedex 05, France
| | - M Reyssat
- UMR CNRS Gulliver 7083, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75231, Paris cedex 05, France
| | - C Monteux
- Laboratoire Sciences et Ingénierie de la Matière Molle, PSL Research University, UPMC Univ Paris 06, ESPCI Paris, UMR 7615 CNRS, 10 rue Vauquelin, 75231, Paris Cedex 05, France.
- Global Station for Soft Matter, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, 060-0808, Hokkaido, Japan.
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Poirier A, Banc A, Stocco A, In M, Ramos L. Multistep building of a soft plant protein film at the air-water interface. J Colloid Interface Sci 2018; 526:337-346. [DOI: 10.1016/j.jcis.2018.04.087] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 04/22/2018] [Accepted: 04/23/2018] [Indexed: 01/24/2023]
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8
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Noskov BA, Krycki MM. Formation of protein/surfactant adsorption layer as studied by dilational surface rheology. Adv Colloid Interface Sci 2017; 247:81-99. [PMID: 28716186 DOI: 10.1016/j.cis.2017.07.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 06/19/2017] [Accepted: 07/02/2017] [Indexed: 12/25/2022]
Abstract
The review discusses the mechanism of formation of protein/surfactant adsorption layers at the liquid - gas interface. The complexes of globular proteins usually preserve their compact structure a low surfactant concentrations. Therefore a simple kinetic model of the adsorption of charged compact nanoparticles is discussed first and compared with experimental data. The increase of surfactant concentrations results in various conformational transitions in the surface layer. One can obtain information on the changes of the adsorption layer structure using the dilational surface rheology. The kinetic dependencies of the dynamic surface elasticity are strongly different for the adsorption of unfolded macromolecules and compact globules, and have local maxima in the former case corresponding to different steps of the adsorption. These distinctions allow tracing the changes of the tertiary structure of protein/surfactant complexes in the surface layer. The adsorption from mixed solutions of ionic surfactants with β-casein, β-lactoglobulin, bovine serum albumin and myoglobin is discussed with some details.
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Truszkowska D, Henrich F, Schultze J, Koynov K, Räder H, Butt HJ, Auernhammer G. Forced dewetting dynamics of high molecular weight surfactant solutions. Colloids Surf A Physicochem Eng Asp 2017. [DOI: 10.1016/j.colsurfa.2016.07.073] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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10
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Bolontrade AJ, Scilingo AA, Añón MC. Amaranth proteins foaming properties: Film rheology and foam stability – Part 2. Colloids Surf B Biointerfaces 2016; 141:643-650. [DOI: 10.1016/j.colsurfb.2014.10.061] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 09/26/2014] [Accepted: 10/22/2014] [Indexed: 11/28/2022]
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11
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Kuchlyan J, Roy A, Dutta R, Sen S, Sarkar N. Effect of the submicellar concentration of bile salts on structural alterations of β-casein micelles. RSC Adv 2016. [DOI: 10.1039/c6ra14804b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The role of bile salts, sodium deoxycholate (NaDC) and sodium cholate (NaCh), on the self-assembly behavior of β-casein micelles (β-CMs) was investigated using various fluorescence techniques.
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Affiliation(s)
- Jagannath Kuchlyan
- Department of Chemistry
- Indian Institute of Technology
- Kharagpur 721302
- India
| | - Arpita Roy
- Department of Chemistry
- Indian Institute of Technology
- Kharagpur 721302
- India
| | - Rupam Dutta
- Department of Chemistry
- Indian Institute of Technology
- Kharagpur 721302
- India
| | - Swagata Sen
- Department of Chemistry
- Indian Institute of Technology
- Kharagpur 721302
- India
| | - Nilmoni Sarkar
- Department of Chemistry
- Indian Institute of Technology
- Kharagpur 721302
- India
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12
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Morioka T, Kawaguchi M. Surface dilational moduli of polymer and blended polymer monolayers spread at air-water interfaces. Adv Colloid Interface Sci 2014; 214:1-16. [PMID: 25456455 DOI: 10.1016/j.cis.2014.10.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 10/07/2014] [Accepted: 10/07/2014] [Indexed: 11/17/2022]
Abstract
Surface dilational moduli of polymer monolayers, blended polymer monolayers, and polymer particle monolayers spread at air-water interfaces are reviewed, focusing on measurements using surface pressure isotherm, surface pressure relaxation, and oscillating barrier methods. Differences between the surface dilational moduli of condensed polymer monolayers and expanded polymer monolayers are explored. Moreover, the features of the surface dilational moduli in blended polymer monolayers are discussed in terms of their miscibility.
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Affiliation(s)
- Takako Morioka
- Division of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya, Tsu, Mie 514-8507, Japan
| | - Masami Kawaguchi
- Division of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya, Tsu, Mie 514-8507, Japan.
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Stanimirova RD, Marinova KG, Danov KD, Kralchevsky PA, Basheva ES, Stoyanov SD, Pelan EG. Competitive adsorption of the protein hydrophobin and an ionic surfactant: Parallel vs sequential adsorption and dilatational rheology. Colloids Surf A Physicochem Eng Asp 2014. [DOI: 10.1016/j.colsurfa.2014.06.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Protein conformational transitions at the liquid-gas interface as studied by dilational surface rheology. Adv Colloid Interface Sci 2014; 206:222-38. [PMID: 24238394 DOI: 10.1016/j.cis.2013.10.024] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2013] [Revised: 10/21/2013] [Accepted: 10/21/2013] [Indexed: 11/21/2022]
Abstract
Experimental results on the dynamic dilational surface elasticity of protein solutions are analyzed and compared. Short reviews of the protein behavior at the liquid-gas interface and the dilational surface rheology precede the main sections of this work. The kinetic dependencies of the surface elasticity differ strongly for the solutions of globular and non-globular proteins. In the latter case these dependencies are similar to those for solutions of non-ionic amphiphilic polymers and have local maxima corresponding to the formation of the distal region of the surface layer (type I). In the former case the dynamic surface elasticity is much higher (>60 mN/m) and the kinetic dependencies are monotonical and similar to the data for aqueous dispersions of solid nanoparticles (type II). The addition of strong denaturants to solutions of bovine serum albumin and β-lactoglobulin results in an abrupt transition from the type II to type I dependencies if the denaturant concentration exceeds a certain critical value. These results give a strong argument in favor of the preservation of the protein globular structure in the course of adsorption without any denaturants. The addition of cationic surfactants also can lead to the non-monotonical kinetic dependencies of the dynamic surface elasticity indicating destruction of the protein tertiary and secondary structures. The addition of anionic surfactants gives similar results only for the protein solutions of high ionic strength. The influence of cationic surfactants on the local maxima of the kinetic dependencies of the dynamic surface elasticity for solutions of a non-globular protein (β-casein) differs from the influence of anionic surfactants due to the heterogeneity of the charge distribution along the protein chain. In this case one can use small admixtures of ionic surfactants as probes of the adsorption mechanism. The effect of polyelectrolytes on the kinetic dependencies of the dynamic surface elasticity of protein solutions is weaker than the effect of conventional surfactants but exceeds the error limits.
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Pérez-Mosqueda LM, Maldonado-Valderrama J, Ramírez P, Cabrerizo-Vílchez MA, Muñoz J. Interfacial characterization of Pluronic PE9400 at biocompatible (air–water and limonene–water) interfaces. Colloids Surf B Biointerfaces 2013; 111:171-8. [DOI: 10.1016/j.colsurfb.2013.05.029] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 05/13/2013] [Accepted: 05/18/2013] [Indexed: 01/17/2023]
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16
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Ramírez P, Stocco A, Muñoz J, Miller R. Interfacial rheology and conformations of triblock copolymers adsorbed onto the water-oil interface. J Colloid Interface Sci 2012; 378:135-43. [PMID: 22575779 DOI: 10.1016/j.jcis.2012.04.033] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 04/11/2012] [Accepted: 04/12/2012] [Indexed: 01/03/2023]
Abstract
The conformation and the dilatational properties of three non-ionic triblock PEO-PPO-PEO (where PEO is polyethyleneoxide and PPO is polypropyleneoxide) copolymers of different hydrophobicity and molecular weight were investigated at the water-hexane interface. The interfacial behavior of the copolymers was studied by combining dilatational rheology using the oscillating drop method and ellipsometry. From the dilatational rheology measurements the limiting elasticity values, E(0), of the Pluronics as function of surface pressure, Π, and adsorption time were obtained, i.e. E(0)(t) and E(0)(Π). Here, it is shown that E(0)(t) depends on the number of PEO units and on the bulk concentration, showing maximum and minimum surface elasticity values which indicate conformational changes in the interfacial layer. Furthermore, in the framework of the polymer scaling law theory, conformational transitions were discussed in E(0) vs. Π plots. In a dilute regime (Π<14 mN m(-1)) at the water-hexane interface, E(0)=2Π fits well all the data, which indicates a two-dimensional "stretched chain" conformation. Increasing Π, two other interfacial transitions could take place. The different behavior of Pluronic copolymers could be also described by the local minima of E(0), which depends on the hydrophobicity of the copolymers. Conformational transitions observed by interfacial rheology were compared to ellipsometric data. Experimental results were discussed and explained on the basis of two- and three-dimensional copolymer structure taking into account that PPO chains could be partially immersed in hexane and water.
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Affiliation(s)
- Pablo Ramírez
- Departamento de Ingeniería Química, Facultad de Química, Universidad de Sevilla, Sevilla, Spain.
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Dynamic interfacial tension of triblock copolymers solutions at the water–hexane interface. Colloids Surf A Physicochem Eng Asp 2011. [DOI: 10.1016/j.colsurfa.2011.04.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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18
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Portnaya I, Khalfin R, Kesselman E, Ramon O, Cogan U, Danino D. Mixed micellization between natural and synthetic block copolymers: β-casein and Lutrol F-127. Phys Chem Chem Phys 2011; 13:3153-60. [DOI: 10.1039/c0cp01321h] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Xin X, Xu G, Ge L, Chen Y, Wang Y, Zhang X, Guo R. Comparison of the Surface Dilational Properties of Block Copolymers and Sodium Oleate Using the Oscillating Bubble Method. J DISPER SCI TECHNOL 2010. [DOI: 10.1080/01932690903218666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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20
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Amado E, Blume A, Kressler J. Adsorbed and spread films of amphiphilic triblock copolymers based on poly(2,3-dihydroxypropyl methacrylate) and poly(propylene oxide) at the air-water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:5507-5519. [PMID: 19950939 DOI: 10.1021/la903748z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The adsorption behavior of the novel type of water-soluble amphiphilic triblock copolymers PGMA-b-PPO-b-PGMA at the air-water interface is studied by tensiometry and monolayer techniques. In particular, (PGMA(14))(2)-PPO(34) is found to be strongly surface active (Pi(max) approximately 38.1 mN/m, cmc approximately 50 microM), in spite of having a relatively short hydrophobic PPO middle block. Time-dependent adsorption measurements exhibit two different types of adsorption kinetics depending on concentration. Monolayers deposited by spreading form pseudo-Langmuir films, in spite of (PGMA(14))(2)-PPO(34) high water solubility. The transition from a dilute to a semidilute regime during compression of the monolayer occurs at a mean molecular area around 4424 A(2)/molecule (Pi = 0.03 mN/m). Above Pi = 2.1 mN/m (1291 A(2)/molecule) PGMA segments begin to change from a flat two-dimensional conformation to loops and tails protruding into the subphase. The onset of the conformational change for PO segments takes place at a mean molecular area of approximately 625 A(2)/molecule (Pi = 15.5 mN/m). In the range Pi approximately 21.4-23.8 mN/m the PPO blocks adopt a three-dimensional conformation. A new methodology for the estimation of the amount of polymer absorbed at the interface (Gamma) as a function of the solution bulk concentration from tensiometry measurements in pseudo-Langmuir spread films is proposed. The obtained adsorption isotherm suggests the occurrence of a conformational change of the PPO block segments toward conformations having smaller molar areas for actual bulk concentrations above 6.0 x 10(-8) M. The surface tension versus polymer bulk concentration curve (gamma vs ln C) exhibits a sharp break at low concentrations, which is probably due to a conformational change within the adsorbed layer. A theoretical multiple conformation model reproduces satisfactorily the experimental dependency of surface pressure on polymer adsorption (Pi vs Gamma) at low and intermediate ranges of polymer concentrations in the solution bulk. A ratio of approximately eight between the average molecular areas at low coverage and at full coverage confirms that (PGMA(14))(2)-PPO(34) chains are highly flexible and able to adopt very different conformations during the transition of the adsorbed polymer film from a highly diluted to a nearly saturated state. There are some experimental indications that nonequilibrium effects might determine a bimodal conformational distribution within the adsorbed (PGMA(14))(2)-PPO(34) layer, which departs substantially from the equilibrium adsorption picture.
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Affiliation(s)
- Elkin Amado
- Martin Luther University Halle-Wittenberg, Institute of Chemistry-Physical Chemistry, D-06099 Halle (Saale), Germany
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Lampe JW, Liao Z, Dmochowski IJ, Ayyaswamy PS, Eckmann DM. Imaging macromolecular interactions at an interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:2452-9. [PMID: 20085337 PMCID: PMC2819646 DOI: 10.1021/la903703u] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Important physiological, pathological, and technological processes occur at continuous and dispersed phase interfaces. Understanding these processes is limited by inability to quantitate molecular events occurring at the interface. To provide a model-independent measurement of protein concentration and mobility at the interface, we employed confocal laser scanning microscopy (CLSM). Fluorescently labeled albumin and fibrinogen were studied singly, pairwise, and with a surfactant, Pluronic F-127, in aqueous droplets. CLSM enables measurement of molecular behaviors manifest as surface inhomogeneity and of biophysical quantities including partitioning between the bulk and the gas-liquid (GL) interface. We conclude that albumin and fibrinogen behave substantially differently at the GL interface, adsorption from multispecies solutions is fundamentally different than adsorption from solutions of single species, and surfactants can inhibit proteins from occupying the interface.
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Affiliation(s)
- Joshua W. Lampe
- Center for Resuscitation Science, Department of Emergency Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA 19104
| | - Zhengzheng Liao
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104
| | - Ivan J. Dmochowski
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104
| | - Portonovo S. Ayyaswamy
- Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA 19104
| | - David M. Eckmann
- Department of Anesthesiology and Critical Care, Hospital of the University of Pennsylvania, Philadelphia, PA 19104
- To whom correspondence should be addressed;
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22
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Gong H, Xu G, Ding H, Shi X, Tan Y. Aggregation behavior of block polyethers with branched structure at air/water surface. Eur Polym J 2009. [DOI: 10.1016/j.eurpolymj.2009.05.027] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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23
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Gaudin JC, Le Parc A, Castrec B, Ropers MH, Choiset Y, Shchutskaya J, Yousefi R, Muronetz VI, Zuev Y, Chobert JM, Haertlé T. Engineering of caseins and modulation of their structures and interactions. Biotechnol Adv 2009; 27:1124-1131. [PMID: 19463935 DOI: 10.1016/j.biotechadv.2009.05.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Beta-casein (beta-CN) is a milk protein widely used in food industries because of its mild emulsifying properties due to its amphiphilicity. However, the elements determining its micellization behavior in solution and interfacial behavior at the air-water interface are not well known. In order to study how the forced dimerisation influences functional properties of beta-CN, recombinant wild-type beta-CN was produced and distal cysteinylated forms of recombinant beta-CN were engineered. We show that 1) cysteinylated beta-CN formed mainly dimers bridged by disulfide bonds; 2) the process of dimerization adds to the micellization process with temperature and is poorly reversible; 3) covalent disulfide linkage forms at the air-water interface at a lower temperature than in bulk. In conclusion, the location of the cysteinylation in the C-terminus or N-terminus or both is of importance for the properties of beta-CN.
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Affiliation(s)
| | - Annabelle Le Parc
- UR 1268 Biopolymères Interactions Assemblages, INRA, 44300 Nantes, France
| | - Benoit Castrec
- UR 1268 Biopolymères Interactions Assemblages, INRA, 44300 Nantes, France
| | | | - Yvan Choiset
- UR 1268 Biopolymères Interactions Assemblages, INRA, 44300 Nantes, France
| | - Juliya Shchutskaya
- UR 1268 Biopolymères Interactions Assemblages, INRA, 44300 Nantes, France; Belozersky Institute of Physico-Chemical Biology, Moscow State University, Lenin's Hills, Moscow, 119992, Russia
| | - Reza Yousefi
- UR 1268 Biopolymères Interactions Assemblages, INRA, 44300 Nantes, France; Department of Biology, College of Sciences, Shiraz University, Shiraz, 71454, Iran
| | - Vladimir I Muronetz
- Belozersky Institute of Physico-Chemical Biology, Moscow State University, Lenin's Hills, Moscow, 119992, Russia
| | - Yuri Zuev
- Kazan Institute of Biochemistry and Biophysics, Kazan, P.O. Box 30, 420111, Russia
| | - Jean-Marc Chobert
- UR 1268 Biopolymères Interactions Assemblages, INRA, 44300 Nantes, France
| | - Thomas Haertlé
- UR 1268 Biopolymères Interactions Assemblages, INRA, 44300 Nantes, France.
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Latnikova AV, Lin SY, Noskov BA. Dynamic surface properties of the solutions of β-casein-surfactant complexes. COLLOID JOURNAL 2009. [DOI: 10.1134/s1061933x09020094] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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25
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Aguié-Béghin V, Sausse P, Meudec E, Cheynier V, Douillard R. Polyphenol-beta-casein complexes at the air/water interface and in solution: effects of polyphenol structure. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2008; 56:9600-9611. [PMID: 18826319 DOI: 10.1021/jf801672x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The interactions between proteins and plant polyphenols are responsible for astringency and haze formation in beverages and may participate in foam stabilization. The effect of phenolic compounds with different structures, namely, catechin (C), epicatechin (Ec), epigallocatechin (Egc), epicatechin gallate (EcG), and epigallocatechin gallate (EgcG), on the surface properties at the air/liquid interface of beta-casein, chosen as model protein, were monitored by tensiometry and ellipsometry. The formation of complexes in the bulk phase was measured by electrospray ionization mass spectrometry (ESI-MS). Adsorption of polyphenols from pure solution was not observed. Surface pressure, surface concentration, and dilational modulus of the protein adsorption layer were greatly modified in the presence of galloylated flavanol monomers (EcG and EgcG) but not of lower molecular weight polyphenols (<306 g/mol). The formation of polyphenol-protein aggregates in the bulk, as evidenced by ESI-MS and light scattering experiments, was related to the slowdown of protein adsorption.
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Affiliation(s)
- V Aguié-Béghin
- INRA UMR 614 Fractionnement des Agro-Ressources et Environnement (FARE) INRA/Universite de Reims Champagne Ardennes, Centre de Recherche en Environnement et Agronomie, 2 Esplanade R. Garros, BP 224, F-51686 Reims, France.
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26
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Dilational surface viscoelasticity of hydroxypropyl methyl cellulose and CnTAB at air–water surface. Carbohydr Polym 2008. [DOI: 10.1016/j.carbpol.2007.08.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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27
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Chang LC, Chang YY, Gau CS. Interfacial properties of Pluronics and the interactions between Pluronics and cholesterol/DPPC mixed monolayers. J Colloid Interface Sci 2008; 322:263-73. [PMID: 18377918 DOI: 10.1016/j.jcis.2008.02.051] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2007] [Revised: 02/26/2008] [Accepted: 02/26/2008] [Indexed: 11/28/2022]
Abstract
Pluronics are triblock copolymers of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) with wide range of hydrophilic-lipophilic balance. In order to investigate the relationship between the chemical structures of Pluronics and the interfacial properties at the air-water interface by monolayer techniques, Pluronics L61, P65, F68, P84, P123, L35, and P105 were selected. Since cholesterol influenced substantially the molecular packing stage and the characteristics of cell membranes, the interactions between Pluronics and model cell membranes in the absence and presence of cholesterol were compared. The results of pi-A isotherms and surface elasticities of Pluronic monolayers indicated that the first and second transition like stage were mainly affected by the numbers of EO and PO monomers, respectively. Pluronics with higher hydrophobicities demonstrated larger surface activities and penetration abilities to dipalmitoylphosphatidylcholine (DPPC) monolayers, which might be due to hydrophobic interactions and van der Waals forces. In the presence of cholesterol, hydrogen bonding effects was supposed to exist between the 3beta-hydroxy group of cholesterol and ether oxygen of PEO chains, which led Pluronic F68, with the longest PEO chain herein, to exhibit significantly higher penetration ability. Our findings proposed a theoretical basis for selection of optimized drug carriers and the starting point for further investigations.
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Affiliation(s)
- Lin-Chau Chang
- School of Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan
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28
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29
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Kiss É, Keszthelyi T, Kormány G, Hakkel O. Adsorbed and Spread Layers of Poly(ethylene oxide)−Poly(propylene oxide)−Poly(ethylene oxide) Block Copolymers at the Air−Water Interface Studied by Sum-Frequency Vibrational Spectroscopy and Tensiometry. Macromolecules 2006. [DOI: 10.1021/ma061161b] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Éva Kiss
- Department of Colloid Chemistry, L. Eötvös University, Budapest 112 P.O. Box 32, H-1518 Hungary, and Chemical Research Centre, P.O. Box 17., H-1525 Budapest, Hungary
| | - Tamás Keszthelyi
- Department of Colloid Chemistry, L. Eötvös University, Budapest 112 P.O. Box 32, H-1518 Hungary, and Chemical Research Centre, P.O. Box 17., H-1525 Budapest, Hungary
| | - Gábor Kormány
- Department of Colloid Chemistry, L. Eötvös University, Budapest 112 P.O. Box 32, H-1518 Hungary, and Chemical Research Centre, P.O. Box 17., H-1525 Budapest, Hungary
| | - Orsolya Hakkel
- Department of Colloid Chemistry, L. Eötvös University, Budapest 112 P.O. Box 32, H-1518 Hungary, and Chemical Research Centre, P.O. Box 17., H-1525 Budapest, Hungary
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30
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Noskov BA. Dynamic elasticity of triblock copolymer of poly(ethylene oxide) and poly(propylene oxide) on a water surface. COLLOID JOURNAL 2006. [DOI: 10.1134/s1061933x06050103] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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31
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Rippner Blomqvist B, Folke S, Claesson PM. The Stabilization of Aqueous PEO‐PPO‐PEO Triblock Copolymer Foam. J DISPER SCI TECHNOL 2006. [DOI: 10.1080/01932690500374201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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32
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Noskov BA, Lin SY, Loglio G, Rubio RG, Miller R. Dilational viscoelasticity of PEO-PPO-PEO triblock copolymer films at the air-water interface in the range of high surface pressures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:2647-52. [PMID: 16519465 DOI: 10.1021/la052662d] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The dynamic dilational elasticity of adsorbed and spread films of PEO-PPO-PEO triblock copolymers at the air-water interface was measured as a function of surface pressure, surface age, and frequency. At low surface pressures (<10 mN/m), the surface viscoelasticity is identical to that of PEO homopolymer films. The results at higher surface pressures can be explained by the desorption of PPO segments from the interface and then mixing with PEO segments in water. Unlike some recent results, the spread and adsorbed films are not identical. Spread films exhibit a maximum real part of the dynamic surface elasticity of about 20 mN/m and probably begin to dissolve in water at surface pressures above 19 mN/m. However, the surface elasticity of the adsorbed films decreases beyond the maximum, indicating the formation of a loose surface structure.
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Affiliation(s)
- B A Noskov
- St. Petersburg State University, Chemical Faculty, Universitetsky pr. 2, 198904 St. Petersburg, Russia
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33
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34
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Calik P, Ileri N, Erdinç BI, Aydogan N, Argun M. Novel antifoam for fermentation processes: fluorocarbon-hydrocarbon hybrid unsymmetrical bolaform surfactant. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:8613-9. [PMID: 16142938 DOI: 10.1021/la050207b] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
As foaming appears as a problem in chemical and fermentation processes that inhibits reactor performance, the eminence of a novel fluorocarbon-hydrocarbon unsymmetrical bolaform (FHUB: OH(CH2)11N+(C2H4)2(CH2)2(CF2)5CF3 I-) surfactant as an antifoaming agent as well as a foam-reducing agent was investigated and compared with other surfactants and a commercial antifoaming agent. The surface elasticity of FHUB was determined as 4 mN/m, indicating its high potential on thinning of the foam film. The interactions between FHUB and the microoganism were investigated in a model fermentation process related with an enzyme production by recombinant Escherichia coli, in V = 3.0 dm3 bioreactor systems with V(R) = 1.65 dm3 working volume at air inlet rate of Q(o)/V(R) = 0.5 dm3 dm(-3) min(-1) and agitation rate of N = 500 min(-1) oxygen transfer conditions, at T = 37 degrees C, pH(o) = 7.2, and C(FHUB) = 0 and 0.1 mM, in a glucose-based defined medium. As FHUB did not influence the metabolism, specific enzyme activity values obtained with and without FHUB were close to each other; however, because of the slight decrease in oxygen transfer coefficient, slightly lower volumetric enzyme activity and cell concentrations were obtained. However, when FHUB is compared with widely used silicon oil based Antifoam A, with the use of the FHUB, higher physical oxygen transfer coefficient (K(L)a) values are obtained. Moreover, as the amount required for the foam control is very low, minute changes in the working volume of the bioreactor were obtained indicating the high potential of the use of FHUB as an antifoaming agent as well as a foam-reducing agent.
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Affiliation(s)
- Pinar Calik
- Department of Chemical Engineering, Industrial Biotechnology Laboratory, Middle East Technical University, 06531 Ankara, Turkey.
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Maldonado-Valderrama J, Fainerman VB, Galvez-Ruiz MJ, Martín-Rodriguez A, Cabrerizo-Vílchez MA, Miller R. Dilatational Rheology of β-Casein Adsorbed Layers at Liquid−Fluid Interfaces. J Phys Chem B 2005; 109:17608-16. [PMID: 16853253 DOI: 10.1021/jp050927r] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The rheological behavior of beta-casein adsorption layers formed at the air-water and tetradecane-water interfaces is studied in detail by means of pendant drop tensiometry. First, its adsorption behavior is briefly summarized at both interfaces, experimentally and also theoretically. Subsequently, the experimental dilatational results obtained for a wide range of frequencies are presented for both interfaces. An interesting dependence with the oscillation frequency is observed via the comparative analysis of the interfacial elasticity (storage part) and the interfacial viscosity (loss part) for the two interfaces. The analysis of the interfacial elasticities provides information on the conformational transitions undergone by the protein upon adsorption at both interfaces. The air-water interface shows a complex behavior in which two maxima merge into one as the frequency increases, whereas only a single maximum is found at the tetradecane interface within the range of frequencies studied. This is interpreted in terms of a decisive interaction between the oil and the protein molecules. Furthermore, the analysis of the interfacial viscosities provides information on the relaxation processes occurring at both interfaces. Similarly, substantial differences arise between the gaseous and liquid interfaces and various possible relaxation mechanisms are discussed. Finally, the experimental elasticities obtained for frequencies higher than 0.1 Hz are further analyzed on the basis of a thermodynamic model. Accordingly, the nature of the conformational transition given by the maximum at these frequencies is discussed in terms of different theoretical considerations. The formation of a protein bilayer at the interface or the limited compressibility of the protein in the adsorbed state are regarded as possible explanations of the maximum.
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Affiliation(s)
- Julia Maldonado-Valderrama
- Grupo de Física de Fluidos y Biocoloides, Department of Applied Physics, University of Granada, Campus de Fuentenueva E-18071 Granada, Spain
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Blomqvist BR, Wärnheim T, Claesson PM. Surface rheology of PEO-PPO-PEO triblock copolymers at the air-water interface: comparison of spread and adsorbed layers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:6373-84. [PMID: 15982044 DOI: 10.1021/la0467584] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The dilatational rheological properties of monolayers of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide)-type block copolymers at the air-water interface have been investigated by employing an oscillating ring trough method. The properties of adsorbed monolayers were compared to spread layers over a range of surface concentrations. The studied polymers were PEO26-PPO39-PEO26 (P85), PEO103-PPO40-PEO103 (F88), and PEO99-PPO65-PEO99 (F127). Thus, two of the polymers have similar PPO block size and two of them have similar PEO block size, which allows us to draw conclusions about the relationship between molecular structure and surface dilatational rheology. The dilatational properties of adsorbed monolayers were investigated as a function of time and bulk solution concentration. The time dependence was found to be rather complex, reflecting structural changes in the layer. When the dilatational modulus measured at different concentrations was replotted as a function of surface pressure, one unique master curve was obtained for each polymer. It was found that the dilatational behavior of spread (Langmuir) and adsorbed (Gibbs) monolayers of the same polymer is close to identical up to surface concentrations of approximately 0.7 mg/m2. At higher coverage, the properties are qualitatively alike with respect to dilatational modulus, although some differences are noticeable. Relaxation processes take place mainly within the interfacial layers by a redistribution of polymer segments. Several conformational transitions were shown to occur as the area per molecule decreased. PEO desorbs significantly from the interface at segmental areas below 20 A(2), while at higher surface coverage, we propose that segments of PPO are forced to leave the interface to form a mixed sublayer in the aqueous region.
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Maldonado-Valderrama J, Fainerman VB, Aksenenko E, Jose Gálvez-Ruiz M, Cabrerizo-Vílchez MA, Miller R. Dynamics of protein adsorption at the oil–water interface: comparison with a theoretical model. Colloids Surf A Physicochem Eng Asp 2005. [DOI: 10.1016/j.colsurfa.2004.10.131] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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38
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Effect of PEO–PPO–PEO structure on the compressed ethylene-induced reverse micelle formation and water solubilization. POLYMER 2005. [DOI: 10.1016/j.polymer.2005.02.105] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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39
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Henni W, Deyme M, Stchakovsky M, LeCerf D, Picton L, Rosilio V. Aggregation of hydrophobically modified polysaccharides in solution and at the air–water interface. J Colloid Interface Sci 2005; 281:316-24. [PMID: 15571687 DOI: 10.1016/j.jcis.2004.08.094] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2004] [Accepted: 08/11/2004] [Indexed: 11/19/2022]
Abstract
The present article focuses on the comparative study of physicochemical properties of two ionic pullulan derivatives modified by 10 or 35 C8 chains per 100 anhydroglucose units, named CMP10C8 and CMP35C8, respectively. In aqueous solutions, these derivatives exhibited an associative behavior as evidenced by pyrene fluorescence spectroscopy. This phenomenon, which stems from intra- and/or intermolecular interactions between the hydrophobic groups grafted on the polymer backbone, results in the formation of more or less condensed aggregates depending on the C8 ratio and the ionic strength of the media. The hydrophobically modified pullulans also displayed surface properties. Their adsorption at the air-solution interface was assessed from surface tension measurements. The results showed that both hydrophobized polymers adsorb in a coil conformation occupying a large interfacial molecular area. The comparison of these molecular areas indicated that CMP35C8 adopts a more shrunken conformation at the interface than CMP10C8, due to stronger intramolecular interactions. The stability of the adsorbed monolayer under bulk dilution was investigated by ellipsometric measurements. Whereas bulk dilution had no effect on the stability of the adsorbed CMP35C8 film, it provoked significant changes in the adsorbed CMP10C8 monolayer. The stability of the CMP35C8 monolayers was attributed to the existence of intermolecular associations between the adsorbed coils.
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Affiliation(s)
- Widad Henni
- Physico-Chimie des Surfaces, UMR CNRS 8612, Université Paris-Sud, 5 Rue Jean-Baptiste Clément, 92296 Châtenay-Malabry Cedex, France
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Monteux C, Fuller GG, Bergeron V. Shear and Dilational Surface Rheology of Oppositely Charged Polyelectrolyte/Surfactant Microgels Adsorbed at the Air−Water Interface. Influence on Foam Stability. J Phys Chem B 2004. [DOI: 10.1021/jp047462+] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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