Vertical order of DPPC multilayer enhanced by cholesterol-induced ripple-to-liquid ordered (LO) phase transition: Synchrotron X-ray reflectivity study

Lee, Suho; Jeong, Dae-Woong; Choi, Myung Chul

doi:10.1016/j.cap.2016.12.022

Cited by 6 publications

(10 citation statements)

References 40 publications

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“…We postulate that the increase in DPPC and BCP lamellar spacings arise due to straightening of hydrophobic chains. We argue that this is a similar effect to the tilt-to-untilt transformation in DPPC, known as a gel-to-liquid ordered (L o ) phase transition, by the addition of cholesterol. − We conjecture that the BCP component (mPEG- b -PCL) acts as cholesterol in particular when PCL is in a crystalline state. This suggestion is consistent to our DSC results shown in Figure S7, and the state of DPPC hydrocarbon chains in hybrid films will be further discussed in the GIWAXS section of the manuscript.…”

Section: Resultssupporting

confidence: 87%

“…This is confirmed by the azimuthal angle plot (Figure S13a of the SI, pink line) that yields two peaks at approximately 10° and 30° which correspond to the (20) and (11) lattice planes of DPPC tilted chain packing . The tilt angle of the DPPC stack can be estimated to be approximately 30°. ,,,, Higher tilt angles of DPPC reduce the average lamellar d -spacing as both chain length and effective size of lipid headgroup, including the hydration volume, contribute to it . For example, Katsaras et al showed that DPPC lamellar stacks with a 21.5° chain tilt and d -spacing of 55.2 Å at 0% RH nonmonotonically increased to tilts of 29.0° and d -spacing of 58.9 Å at 100% RH.…”

Section: Resultsmentioning

confidence: 73%

“…This difference can be justified by slower solvent evaporation kinetics in bulk and capillary samples compared to spin-coated films. This leads to larger lamellar spacings and PEG crystallinity in bulk ( d = 157 Å, neat BCP) than in a film ( d = 144.2 Å, neat BCP). ,, GIWAXS is a versatile tool to investigate molecular packing and orientation of lipids and BCPs. ,,,,− Neat DPPC films display lateral in-plane diffraction arising from lipid tail packing along the q r axis as shown in the right inset of Figure a (100 wt % DPPC). , Figure b (inset) shows partially integrated I ( q ) plots over angles φ = 10° to 50° (at intervals of 10°), where φ refers to the angle from the q r axis. The relative intensity of the broad peak at q = 1.51 Å –1 and the shoulder at q = 1.55 Å –1 vary as a function of φ.…”

Section: Resultsmentioning

confidence: 99%

“…89 The tilt angle of the DPPC stack can be estimated to be approximately 30°. 88,89,100,105,106 Higher tilt angles of DPPC reduce the average lamellar d-spacing as both chain length and effective size of lipid headgroup, including the hydration volume, contribute to it. 89 For example, Katsaras et al showed that DPPC lamellar stacks with a 21.5°chain tilt and d-spacing of 55.2 Å at 0% RH nonmonotonically increased to tilts of 29.0°and d-spacing of 58.9 Å at 100% RH.…”

Section: Mpeg-b-pcl (Bcps) and Dppc (Lipids) Assemble Into Multilamel...mentioning

confidence: 99%

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Reorientation of Crystalline Block Copolymer Membranes by Phospholipid Hybridization

Shin

Chen

et al. 2022

Chem. Mater.

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Block copolymer (BCP) self-assembly and crystallization determine their fundamental mechanical, optical, and transport properties. Multiple physical and chemical routes to control BCP self-assembly have been developed over the years. In contrast, modulating the crystallization behavior, particularly crystallite size and orientation, has received considerably less attention. This paper underpins that 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) phospholipid additives enable precise control of BCP crystallization via a combination of interfacial and confinement effects. The assembly and crystallization behavior of methoxy-poly(ethylene glycol)-b-poly(ε-caprolactone) (mPEG-b-PCL) hybridized with DPPC was elucidated in solid-supported dry-film forms. mPEG-b-PCL/DPPC hybrid films coassemble into multilamellar structures with BCP and lipid domains stacked in registry across the film thickness. With small amounts of DPPC (3 wt %), mPEG-b-PCL/DPPC hybrid films unexpectedly exhibit nonadditive thermal conductivity, reaching ∼0.1 W m–1 K–1, a value considerably lower than pure BCP or DPPC films. Hybridization alters DPPC chain packing and induces specific PCL crystallite orientation at the nanoscale. PCL chains on the folding plane of an orthorhombic lattice optimize molecular interactions with vertically aligned DPPC alkyl chains by orienting PCL crystallites at a 20° tilt. These results enable new applications of polymeric systems in which switchable crystallization routes are used to tune heat transport.

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Section: Resultssupporting

confidence: 87%

Section: Resultsmentioning

confidence: 73%

Section: Resultsmentioning

confidence: 99%

Section: Mpeg-b-pcl (Bcps) and Dppc (Lipids) Assemble Into Multilamel...mentioning

confidence: 99%

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Reorientation of Crystalline Block Copolymer Membranes by Phospholipid Hybridization

Shin

Chen

et al. 2022

Chem. Mater.

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“…6 ). The cross-sectional beam size of incident X-ray was 500 × 400 μm 2 , which is large enough to ensure the averaging effect 35 . The SLB (DOPC:B-PE = 95:5) in the DIW was formed via the vesicle fusion method on the 300 nm-thick SiO 2 -coated Si wafer and annealed at 40 °C for 30 min.…”

Section: Methodsmentioning

confidence: 99%

Ionic contrast across a lipid membrane for Debye length extension: towards an ultimate bioelectronic transducer

et al. 2021

Self Cite

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Despite technological advances in biomolecule detections, evaluation of molecular interactions via potentiometric devices under ion-enriched solutions has remained a long-standing problem. To avoid severe performance degradation of bioelectronics by ionic screening effects, we cover probe surfaces of field effect transistors with a single film of the supported lipid bilayer, and realize respectable potentiometric signals from receptor–ligand bindings irrespective of ionic strength of bulky solutions by placing an ion-free water layer underneath the supported lipid bilayer. High-energy X-ray reflectometry together with the circuit analysis and molecular dynamics simulation discovered biochemical findings that effective electrical signals dominantly originated from the sub-nanoscale conformational change of lipids in the course of receptor–ligand bindings. Beyond thorough analysis on the underlying mechanism at the molecular level, the proposed supported lipid bilayer-field effect transistor platform ensures the world-record level of sensitivity in molecular detection with excellent reproducibility regardless of molecular charges and environmental ionic conditions.

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Dissimilar action of tamoxifen and 4-hydroxytamoxifen on phosphatidylcholine model membranes

Ortiz

Aranda

Teruel

et al. 2021

Biophysical Chemistry

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Vertical order of DPPC multilayer enhanced by cholesterol-induced ripple-to-liquid ordered (LO) phase transition: Synchrotron X-ray reflectivity study

Cited by 6 publications

References 40 publications

Reorientation of Crystalline Block Copolymer Membranes by Phospholipid Hybridization

Reorientation of Crystalline Block Copolymer Membranes by Phospholipid Hybridization

Ionic contrast across a lipid membrane for Debye length extension: towards an ultimate bioelectronic transducer

Dissimilar action of tamoxifen and 4-hydroxytamoxifen on phosphatidylcholine model membranes

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