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Stengel D, Thai R, Li Y, Peters NM, Holland GP. Biphasic nature of lipid bilayers assembled on silica nanoparticles and evidence for an interdigitated phase. SOFT MATTER 2023; 19:1882-1889. [PMID: 36799359 DOI: 10.1039/d2sm01517j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Functionalizing silica nanoparticles with a lipid bilayer shell is a common first step in fabricating drug delivery and biosensing devices that are further decorated with other biomolecules for a range of nanoscience applications and therapeutics. Although the molecular structure and dynamics of lipid bilayers have been thoroughly investigated on larger 100 nm-1 μm silica spheres where the lipid bilayer exhibits the typical Lα bilayer phase, the molecular organization of lipids assembled on mesoscale (4-100 nm diameter) nanoparticles is scarce. Here, DSC, TEM and 2H and 31P solid-state NMR are implemented to probe the organization of 1,2-dipalmitoyl-d54-glycero-3-phosphocholine (DMPC-d54) assembled on mesoscale silica nanoparticles illustrating a significant deviation from Lα bilayer structure due to the increasing curvature of mesoscale supports. A biphasic system is observed that exhibits a combination of high-curvature, non-lamellar and lamellar phases for mesoscale (<100 nm) supports with evidence of an interdigitated phase on the smallest diameter support (4 nm).
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Affiliation(s)
- Dillan Stengel
- Department of Chemistry and Biochemistry, San Diego State University, 5500 Campanile Dr, San Diego CA, 92182-1030, USA.
| | - Rich Thai
- Department of Chemistry and Biochemistry, San Diego State University, 5500 Campanile Dr, San Diego CA, 92182-1030, USA.
| | - Yuan Li
- Department of Chemistry and Biochemistry, San Diego State University, 5500 Campanile Dr, San Diego CA, 92182-1030, USA.
| | - Nikki M Peters
- Department of Chemistry and Biochemistry, San Diego State University, 5500 Campanile Dr, San Diego CA, 92182-1030, USA.
| | - Gregory P Holland
- Department of Chemistry and Biochemistry, San Diego State University, 5500 Campanile Dr, San Diego CA, 92182-1030, USA.
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Andrzejewska W, Wilkowska M, Skrzypczak A, Kozak M. Ammonium Gemini Surfactants Form Complexes with Model Oligomers of siRNA and dsDNA. Int J Mol Sci 2019; 20:ijms20225546. [PMID: 31703275 PMCID: PMC6887939 DOI: 10.3390/ijms20225546] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Revised: 10/30/2019] [Accepted: 11/04/2019] [Indexed: 02/07/2023] Open
Abstract
Dimeric cationic surfactants (gemini-type) are a group of amphiphilic compounds with potential use in gene therapy as effective carriers for nucleic acid transfection (i.e., siRNA, DNA, and plasmid DNA). Our studies have shown the formation of lipoplexes composed of alkanediyl-α,ω-bis[(oxymethyl)dimethyldodecylammonium] chlorides and selected 21-base-pair nucleic acid (dsDNA and siRNA) oligomers. To examine the structure and physicochemical properties of these systems, optical microscopy, circular dichroism spectroscopy (CD), small-angle X-ray scattering of synchrotron radiation (SR-SAXS), and agarose gel electrophoresis (AGE) were used. The lengths of spacer groups of the studied surfactants had a significant influence on the surfactants’ complexing properties. The lowest charge ratio (p/n) at which stable lipoplexes were observed was 1.5 and the most frequently occurring microstructure of these lipoplexes were cubic and micellar phases for dsDNA and siRNA, respectively. The cytotoxicity tests on HeLa cells indicated the non-toxic concentration of surfactants to be at approximately 10 µM. The dicationic gemini surfactants studied form complexes with siRNA and dsDNA oligomers; however, the complexation process is more effective towards siRNA. Therefore these systems could be applied as transfection systems for therapeutic nucleic acids.
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Affiliation(s)
- Weronika Andrzejewska
- Department of Macromolecular Physics, Faculty of Physics, Adam Mickiewicz University, Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland; (W.A.); (M.W.)
- NanoBioMedical Centre, Adam Mickiewicz University, Wszechnicy Piastowskiej 3, 61-614 Poznań, Poland
| | - Michalina Wilkowska
- Department of Macromolecular Physics, Faculty of Physics, Adam Mickiewicz University, Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland; (W.A.); (M.W.)
| | - Andrzej Skrzypczak
- Faculty of Chemical Technology, Poznan University of Technology, Berdychowo 4, 60-965 Poznań, Poland;
| | - Maciej Kozak
- Department of Macromolecular Physics, Faculty of Physics, Adam Mickiewicz University, Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland; (W.A.); (M.W.)
- Joint SAXS Laboratory, Adam Mickiewicz University, Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland
- Correspondence: ; Tel.: +48-61-829-5266
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Diouf SIY, Williams DJ, Seifert S, Londoño-Calderon A, Pettes MT, Sheehan CJ, Firestone MA. Multi-stimuli responsive tetra-PPO60-PEO20 ethylene diamine block copolymer enables pH, temperature, and solvent regulation of Au nanoparticle composite plasmonic response. Polym Chem 2019. [DOI: 10.1039/c9py01098j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Dynamic plasmonic tuning of Au NP organization through pH and temperature mediated polymer architecture transformation from lamellar to bicontinuous cubic.
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Tapia MJ, Monteserín M, Burrows HD, Almeida JAS, Pais AACC, Pina J, Seixas de Melo JS, Jarmelo S, Estelrich J. From molecular modelling to photophysics of neutral oligo- and polyfluorenes incorporated into phospholipid bilayers. SOFT MATTER 2015; 11:303-317. [PMID: 25411076 DOI: 10.1039/c4sm02145b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The combination of various experimental techniques with theoretical simulations has allowed elucidation of the mode of incorporation of fluorene based derivatives into phospholipid bilayers. Molecular dynamics (MD) simulations on a fully hydrated 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine (DMPC) bilayer, with benzene (B), biphenyl (BP), fluorene (F) and tri-(9,9-di-n-octylfluorenyl-2,7-diyl), TF, have provided insights into the topography of these molecules when they are present in the phospholipid bilayer, and suggest marked differences between the behavior of the small molecules and the oligomer. Further information on the interaction of neutral fluorenes within the phospholipid bilayer was obtained by an infrared (IR) spectroscopic study of films of DMPC and of the phospholipid with PFO deuterated specifically on its alkyl chains (DMPC-PFO-d34). This was complemented by measurements of the effect of F, TF and two neutral polymers: polyfluorene poly(9,9-di-n-octylfluorenyl-2,7-diyl), PFO, and poly(9,9-di-n-dodecylfluorenyl-2,7-diyl), PFD, on the phospholipid phase transition temperature using differential scanning calorimetry (DSC). Changes in liposome size upon addition of F and PFO were followed by dynamic light scattering. In addition, the spectroscopic properties of F, TF, PFO and PFD solubilised in DMPC liposomes (absorption, steady-state and time-resolved fluorescence) were compared with those of the same probes in typical organic solvents (chloroform, cyclohexane and ethanol). Combining the insight from MD simulations with the results at the molecular level from the various experimental techniques suggests that while the small molecules have a tendency to be located in the phospholipid head group region, the polymers are incorporated within the lipid bilayers, with the backbone predominantly orthogonal to the phospholipid alkyl chains and with interdigitation of them and the PFO alkyl chains.
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Affiliation(s)
- M J Tapia
- Departamento de Química, Universidad de Burgos, Plaza Misael Bañuelos s/n, 09001 Burgos, Spain.
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Hädicke A, Blume A. Interactions of Pluronic block copolymers with lipid vesicles depend on lipid phase and Pluronic aggregation state. Colloid Polym Sci 2014. [DOI: 10.1007/s00396-014-3414-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Kozak M, Szpotkowski K, Kozak A, Zieliński R, Wieczorek D, Gajda MJ, Domka L. The FTIR and SAXS studies of influence of a morpholine derivatives on the DMPC-based biological membrane systems. Radiat Phys Chem Oxf Engl 1993 2009. [DOI: 10.1016/j.radphyschem.2009.03.090] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Angelov B, Angelova A, Vainio U, Garamus VM, Lesieur S, Willumeit R, Couvreur P. Long-living intermediates during a lamellar to a diamond-cubic lipid phase transition: a small-angle X-ray scattering investigation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:3734-3742. [PMID: 19708151 DOI: 10.1021/la804225j] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
To generate nanostructured vehicles with tunable internal organization, the structural phase behavior of a self-assembled amphiphilic mixture involving poly(ethylene glycol) monooleate (MO-PEG) and glycerol monooleate (MO) is studied in excess aqueous medium by time-resolved small-angle X-ray scattering (SAXS) in the temperature range from 1 to 68 degrees C. The SAXS data indicate miscibility of the two components in lamellar and nonlamellar soft-matter nanostructures. The functionalization of the MO assemblies by a MO-PEG amphiphile, which has a flexible large hydrophilic moiety, appears to hinder the epitaxial growth of a double diamond (D) cubic lattice from the lamellar (L) bilayer structure during the thermal phase transition. The incorporated MO-PEG additive is found to facilitate the formation of structural intermediates. They exhibit greater characteristic spacings and large diffusive scattering in broad temperature and time intervals. Their features are compared with those of swollen long-living intermediates in MO/octylglucoside assemblies. A conclusion can be drawn that long-living intermediate states can be equilibrium stabilized in two- or multicomponent amphiphilic systems. Their role as cubic phase precursors is to smooth the structural distortions arising from curvature mismatch between flat and curved regions. The considered MO-PEG functionalized assemblies may be useful for preparation of sterically stabilized liquid-crystalline nanovehicles for confinement of therapeutic biomolecules.
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Affiliation(s)
- Borislav Angelov
- Institute of Biophysics, Bulgarian Academy of Sciences, BG-1113 Sofia, Bulgaria
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Frey SL, Lee KYC. Temperature dependence of poloxamer insertion into and squeeze-out from lipid monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:2631-7. [PMID: 17309214 DOI: 10.1021/la0626398] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
F68, a triblock copolymer of the form poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide), is found to effectively seal damaged cell membranes. To better understand the molecular interaction between F68 and cells, we have modeled the outer leaflet of a cell membrane with a dipalmitoylphosphatidylcholine (DPPC) monolayer spread at the air-water interface and introduced poloxamer into the subphase. Subsequent interactions of the polymer with the monolayer either upon expansion or compression were monitored using concurrent Langmuir isotherm and fluorescence microscopy measurements. To alter the activity of the poloxamer, a range of subphase temperatures from 5 to 37 degrees C was used. Lower temperatures increase the solubility of the poloxamer in the subphase and therefore lessen the amount of material at the interface, resulting in a lower equilibrium spreading pressure. Additionally, changes in temperature affect the phase behavior of DPPC. Below the triple point, the monolayer is condensed at pertinent polymer insertion pressures; for temperatures immediately above the triple point, the monolayer is a heterogeneous mix of liquid expanded and condensed phase; for the highest temperature measured, the DPPC monolayer remains completely fluid. At all temperatures, F68 inserts into DPPC monolayers at its equilibrium spreading pressure. Upon compression of the monolayer, polymers are squeezed-out at surface pressures notably higher than those for insertion, with higher temperatures leading to a higher squeeze-out pressure. An increase in temperature decreases the solvent quality of water for the poloxamer, lowering solubility of the polymer in the subphase and thus increasing its propensity to be maintained within the monolayer to higher pressures.
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Affiliation(s)
- Shelli L Frey
- Department of Chemistry, Institute for Biophysical Dynamics and James Franck Institute, The University of Chicago, Chicago, IL 60637, USA
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Cao X, Xu G, Li Y, Zhang Z. Aggregation of Poly(ethylene oxide)−Poly(propylene oxide) Block Copolymers in Aqueous Solution: DPD Simulation Study. J Phys Chem A 2005; 109:10418-23. [PMID: 16833339 DOI: 10.1021/jp053636r] [Citation(s) in RCA: 68] [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 dissipative particle dynamics (DPD) simulation method was applied to simulate the aggregation behavior of three block copolymers, (EO)16(PO)18, (EO)8(PO)18(EO)8, and (PO)9(EO)16(PO)9, in aqueous solutions. The results showed that the size of the micelle increased with increasing concentration. The diblock copolymer (EO)16(PO)18 would form an intercluster micelle at a certain concentration range, besides the traditional aggregates (spherical micelle, cylindrical micelle, and lamellar phase); while the triblock copolymer (EO)8(PO)18(EO)8 would form a spherical micelle, cylindrical micelle, and lamellar phase with increasing concentration, and (PO)9(EO)16(PO)9 would form intercluster aggregates, as well as a spherical micelle and gel. New mechanisms were given to explain the two kinds of intercluster micelle formed by the different copolymers. It is deduced from the end-to-end distance that the morphologies of the diblock copolymer and triblock copolymer with hydrophilic ends were more extendible than the triblock copolymer with hydrophobic ends.
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Affiliation(s)
- Xiaorong Cao
- Key Laboratory of Colloid and Interface Chemistry (Shandong University), Ministry of Education, Jinan 250100, P. R. China
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