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Dash S, Chowdhury UD, Bhargava BL. The effect of external salts on the aggregation of the multiheaded surfactants: All-atom molecular dynamics studies. J Mol Graph Model 2021; 111:108110. [PMID: 34959150 DOI: 10.1016/j.jmgm.2021.108110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 12/13/2021] [Accepted: 12/13/2021] [Indexed: 12/01/2022]
Abstract
Tailoring the molecular design of the surfactants leads to changes in the aggregation properties. The role of external salts on the aggregation properties of the multiheaded surfactants is investigated using molecular dynamics simulations. The multiheaded surfactants show differential aggregation properties on addition of external salts, as reported earlier from experimental studies. We have modelled the multiheaded surfactants to study the effect of external salts (potassium bromide and sodium salicylate) at three different concentrations using the all-atom modelling and explicit solvation. The influence of external salts on the hydration and aggregation propensity, hydrogen bonding, and the structural characteristics of the surfactant aggregates are probed using various analyses across the four groups of multiheaded surfactants. The larger salicylate ion masks the repulsion between the cationic head groups and acts as an effective promoter of aggregation.
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Affiliation(s)
- Sandeep Dash
- School of Chemical Sciences, National Institute of Science Education & Research-Bhubaneswar, HBNI, P.O.Jatni, Khurda, Odisha, 752 050, India
| | - Unmesh D Chowdhury
- School of Chemical Sciences, National Institute of Science Education & Research-Bhubaneswar, HBNI, P.O.Jatni, Khurda, Odisha, 752 050, India
| | - B L Bhargava
- School of Chemical Sciences, National Institute of Science Education & Research-Bhubaneswar, HBNI, P.O.Jatni, Khurda, Odisha, 752 050, India.
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2
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Zumbuehl A. Artificial Phospholipids and Their Vesicles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:10223-10232. [PMID: 30278137 DOI: 10.1021/acs.langmuir.8b02601] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Phospholipids are at the heart and origin of life on this planet. The possibilities in terms of phospholipid self-assembly and biological functions seem limitless. Nonetheless, nature exploits only a small fraction of the available chemical space of phospholipids. Using chemical synthesis, artificial phospholipid structures become accessible, and the study of their biophysics may reveal unprecedented properties. In this article, the recent advances by our work group in the field of chemical lipidology are summarized. The family of diamidophospholipids is discussed in detail from monolayer characterization to the formation of faceted vesicles, culminating in the template-free self-assembly of phospholipid cubes and the possible applications of vesicle origami in modern personalized medicine.
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Affiliation(s)
- Andreas Zumbuehl
- Department of Chemistry , University of Fribourg , Chemin du Musée 9 , 1700 Fribourg , Switzerland
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Sharma A, Bhargava BL. Self-Assembly of Cations in Aqueous Solutions of Multiheaded Cationic Surfactants: All Atom Molecular Dynamics Simulation Studies. J Phys Chem B 2018; 122:10943-10952. [PMID: 30383378 DOI: 10.1021/acs.jpcb.8b08911] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Self-assembly of multiheaded surfactants in aqueous solutions has been investigated using atomistic molecular dynamics simulations. The model multiheaded surfactants contain multiple head groups ranging from one to four for a single tail group. Increase in the number of charged head groups has substantial consequences in the aggregation properties of surfactants in their aqueous solutions. Polydisperse aggregates of surfactants are formed in the aqueous solution. The shape and size of the aggregates are dictated by the number of charged head groups present in the surfactant. Our simulations demonstrate that with the increase in the number of charged head groups on the surfactants, the aggregation number decreases, which corroborates previous experimental and theoretical studies. Though experimental studies on the surfactant with four head groups is yet to be performed, we have included the surfactant having four head groups in our studies and compared the results with previous coarse-grained computational study involving four head groups.
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Affiliation(s)
- Anirban Sharma
- School of Chemical Sciences , National Institute of Science Education & Research-Bhubaneswar, HBNI , P.O. Jatni, Khurda , Odisha 752050 , India
| | - B L Bhargava
- School of Chemical Sciences , National Institute of Science Education & Research-Bhubaneswar, HBNI , P.O. Jatni, Khurda , Odisha 752050 , India
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Matelová A, Huerta-Angeles G, Šmejkalová D, Brůnová Z, Dušek J, Vícha R, Velebný V. Synthesis of novel amphiphilic hyaluronan containing-aromatic fatty acids for fabrication of polymeric micelles. Carbohydr Polym 2016; 151:1175-1183. [DOI: 10.1016/j.carbpol.2016.06.085] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 06/19/2016] [Accepted: 06/20/2016] [Indexed: 12/29/2022]
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5
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Sarkar D, Shukla RK, Gadgil V, Pramanik A. Head group specificity of novel functionalized surfactants: synthesis, self-assembly and calcium tolerance. Tetrahedron Lett 2014. [DOI: 10.1016/j.tetlet.2014.08.111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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6
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Monks BM, Fruchey ER, Cook SP. Iron-Catalyzed C(sp2)H Alkylation of Carboxamides with Primary Electrophiles. Angew Chem Int Ed Engl 2014; 53:11065-9. [DOI: 10.1002/anie.201406594] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Indexed: 11/09/2022]
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7
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Monks BM, Fruchey ER, Cook SP. Iron-Catalyzed C(sp2)H Alkylation of Carboxamides with Primary Electrophiles. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201406594] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Wang Z, Li Y, Guo Y, Zhang H. Investigations of Interfacial Properties of Surfactants with Different Structures at the Oil/Water Interface Using Dissipative Particle Dynamics. J DISPER SCI TECHNOL 2013. [DOI: 10.1080/01932691.2012.731637] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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9
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Li Y, Zhang H, Bao M, Chen Q. Aggregation Behavior of Surfactants with Different Molecular Structures in Aqueous Solution: DPD Simulation Study. J DISPER SCI TECHNOL 2012. [DOI: 10.1080/01932691.2011.620897] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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10
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De S, Aswal VK, Ramakrishnan S. Phenyl-ring-bearing cationic surfactants: effect of ring location on the micellar structure. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:17882-17889. [PMID: 21067129 DOI: 10.1021/la1036053] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A series of isomeric cationic surfactants (S1-S5) bearing a long alkyl chain that carries a 1,4-phenylene unit and a trimethyl ammonium headgroup was synthesized; the location of the phenyl ring within the alkyl tail was varied in an effort to understand its influence on the amphiphilic properties of the surfactants. The cmc's of the surfactants were estimated using ionic conductivity measurements and isothermal calorimetric titrations (ITC); the values obtained by the two methods were found to be in excellent agreement. The ITC measurements provided additional insight into the various thermodynamic parameters associated with the micellization process. Although all five surfactants have exactly the same molecular formula, their micellar properties were seen to vary dramatically depending on the location of the phenyl ring; the cmc was seen to decrease by almost an order of magnitude when the phenyl ring was moved from the tail end (cmc of S1 is 23 mM) to the headgroup region (cmc of S5 is 3 mM). In all cases, the enthalpy of micellization was negative but the entropy of micellization was positive, suggesting that in all of these systems the formation of micelles is both enthalpically and entropically favored. As expected, the decrease in cmc values upon moving the phenyl ring from the tail end to the headgroup region is accompanied by an increase in the thermodynamic driving force (ΔG) for micellization. To understand further the differences in the micellar structure of these surfactants, small-angle neutron scattering (SANS) measurements were carried out; these measurements reveal that the aggregation number of the micelles increases as the cmc decreases. This increase in the aggregation number is also accompanied by an increase in the asphericity of the micellar aggregate and a decrease in the fractional charge. Geometric packing arguments are presented to account for these changes in aggregation behavior as a function of phenyl ring location.
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Affiliation(s)
- Swati De
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560 012, India
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Bhattacharya S, Biswas J. Understanding membranes through the molecular design of lipids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:4642-54. [PMID: 19842629 DOI: 10.1021/la9011718] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Lipids are amphiphilic molecules that are composed of hydrophilic and hydrophobic regions. A typical membranous aggregate (vesicles, water-filled lipid nanospheres) is formed upon the self-organization of lipids in water from a diverse collection of amphiphiles producing a dynamic supramolecular structure that shows phase behavior and ordering as required for specific biological functions. The determination of various physical properties of lipid aggregates is the key to determining structure-function relationships. Over the years, we have designed and synthesized a wide variety of lipid molecular systems for the investigation of their membrane-forming properties and have used them for purposes such as gene delivery and enzyme activation. In this feature article, we focus on our work on various types of lipids including ion-paired amphiphiles, cholesterol-based lipids, aromatic lipids, macrocyclic lipids containing disulfide tethers, cationic dimeric lipids, and so forth. The emphasis is on experimental design and bottom-line conclusions.
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Affiliation(s)
- Santanu Bhattacharya
- Department of Organic Chemistry, Indian Institute of Science, Bangalore 560 012, India.
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12
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Coarse-grained molecular dynamics simulation of the aggregation properties of multiheaded cationic surfactants in water. J Phys Chem B 2009; 113:13545-50. [PMID: 19775096 DOI: 10.1021/jp902376y] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The aggregation property of multiheaded surfactants has been investigated by constant pressure molecular dynamics (MD) simulation in aqueous medium. The model multiheaded surfactants contain more than one headgroup (x = 2, 3, and 4) for a single tail group. This increases the hydrophilic charge progressively over the hydrophobic tail which has dramatic consequences in the aggregation behavior. In particular, we have looked at the change in the aggregation property such as critical micellar concentration (cmc), aggregation number, and size of the micelles for the multiheaded surfactants in water. We find with increasing number of headgroups of the multiheaded surfactants that the cmc values increase and the aggregation numbers as well as the size of the micelles decrease. These trends are in agreement with the experimental findings as reported earlier with x = 1, 2, and 3. We also predict the aggregation properties of multiheaded surfactant with four headgroups (x = 4) for which no experimental studies exist yet.
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Bhattacharya S, Bajaj A. Advances in gene delivery through molecular design of cationic lipids. Chem Commun (Camb) 2009:4632-56. [DOI: 10.1039/b900666b] [Citation(s) in RCA: 232] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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14
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Paul B, Bajaj A, Indi S, Bhattacharya S. Synthesis of novel dimeric cationic lipids based on an aromatic backbone between the hydrocarbon chains and headgroup. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2006.09.072] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Visscher I, Stuart MCA, Engberts JBFN. The influence of phenyl and phenoxy modification in the hydrophobic tails of di-n-alkyl phosphate amphiphiles on aggregate morphology. Org Biomol Chem 2006; 4:707-12. [PMID: 16467945 DOI: 10.1039/b514285g] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of di-n-alkyl phosphate amphiphiles containing phenyl and phenoxy groups in the hydrophobic tails were synthesised, and their aggregation behaviour was investigated using fluorescence spectroscopy, differential scanning calorimetry, and cryo-electron microscopy. The aggregates displayed a wide variety of aggregate morphologies. The incorporation of a phenyl group into the end or in the middle of the alkyl chain lowered the main phase transition temperature, resulting in closed vesicles only above the phase transition temperature. Introducing a phenoxy group at the end of the alkyl chain resulted in open bilayer structures and bicelles.
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Affiliation(s)
- Inge Visscher
- Physical Organic Chemistry Unit, Stratingh Institute, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
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