Kulkarni, CV, Yaghmur, A, Steinhart, M et al. (2 more authors) (2016) Effects of High Pressure on Internally Self-Assembled Lipid Nanoparticles: A Synchrotron Small-Angle X-ray Scattering (SAXS) Study. Langmuir, 32 (45). pp. 11907-11917. ISSN 0743-7463
Abstract
We present the first report on the effects of hydrostatic pressure on colloidally stabilized lipid nanoparticles enveloping inverse nonlamellar self-assemblies in their interiors. These internal self-assemblies were systematically tuned into bicontinuous cubic (Pn3m and Im3m), micellar cubic (Fd3m), hexagonal (H2), and inverse micellar (L2) phases by regulating the lipid/oil ratio as the hydrostatic pressure was varied from atmospheric pressure to 1200 bar and back to atmospheric pressure. The effects of pressure on these lipid nanoparticles were compared with those on their equilibrium bulk, nondispersed counterparts, namely, inverse nonlamellar liquid-crystalline phases and micellar solutions under excess-water conditions, using the synchrotron small-angle X-ray scattering (SAXS) technique. In the applied pressure range, induced phase transitions were observed solely in fully hydrated bulk samples, whereas the internal self-assemblies of the corresponding lipid nanoparticles displayed only pressure-modulated single phases. Interestingly, both the lattice parameters and the linear pressure expansion coefficients were larger for the self-assemblies enveloped inside the lipid nanoparticles as compared to the bulk states. This behavior can, in part, be attributed to enhanced lipid layer undulations in the lipid particles in addition to induced swelling effects in the presence of the triblock copolymer F127. The bicontinuous cubic phases both in the bulk state and inside lipid cubosome nanoparticles swell on compression, even as both keep swelling further upon decompression at relatively high pressures before shrinking again at ambient pressures. The pressure dependence of the phases is also modulated by the concentration of the solubilized oil (tetradecane). These studies demonstrate the tolerance of lipid nanoparticles [cubosomes, hexosomes, micellar cubosomes, and emulsified microemulsions (EMEs)] for high pressures, confirming their robustness for various technological applications.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016 American Chemical Society. This document is the Accepted Manuscript version of a Published Work that appeared in final form in Langmuir, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.langmuir.6b03300. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Food Science and Nutrition (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 23 Nov 2016 11:47 |
Last Modified: | 26 Oct 2017 21:55 |
Published Version: | https://doi.org/10.1021/acs.langmuir.6b03300 |
Status: | Published |
Publisher: | American Chemical Society |
Identification Number: | 10.1021/acs.langmuir.6b03300 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:108216 |