Limited Slowdown of Endocrine-Disruptor Diffusion in Confined Fluid Lipid Membranes

Abstract

Self-diffusion rates of lipids and trapped bisphenol A (BPA) are determined in various sizes of confined but fluid membranes by high-field-gradient NMR at 600 MHz. Micelles and vesicles of 3- to 400-nm diameters are used as model membranes to get an insight into the molecular diffusion in such soft environments. The slowdown of BPA and lipid motions is leveled off in 100- and 400-nm vesicles, although the hydrodynamic continuum model gives the aggregate motion slowed inversely to the aggregate size. Instead, the limited motion is related to the intra-membrane fluidity.

Uptake of Sevoflurane Limited by the Presence of Cholesterol in the Lipid Bilayer Membrane: A Multinuclear Nuclear Magnetic Resonance Study

“…1, conditioned by the experimental time scale. If the time scale is not long enough, the D value of the drug is not necessarily equal to the value of the membrane molecule 25 , while it is a certain measure of the molecular mobility in the lipid vesicular membrane 26 . The measurements were repeated 2-4 times at 30 where the lipid was in the fluid liquid-crystalline L α phase.…”

Kinetics of Membrane Binding and Mobility of Drugs by Multinuclear Dynamic NMR <i>in Situ</i>

“…/s for FBPA [8,13,17], the mobility significantly slowed down as compared to that of the free component. Interestingly, D B of both drugs is almost comparable to that of the lipid molecules 0.1 10 10 m 2 /s in LUV [8,13], indicating that the molecular motion in the soft membrane environment is closely related to the intramembrane fluidity [8,9].…”

“…It is an extension of the high-field-gradient NMR study on the mobility of lipids and trapped drugs in fluid lipid membranes [9]. Okamura and Yoshii have succeeded in distinguishing both bound and free states of the drug in situ, to quantify how much of the drug is bound to the membrane without any separation procedures of the bound and the free species.…”

Effect of phosphatidylcholine vesicle size on chirality induction and chiral discrimination

“…Thus, the conversion between P and M enantiomers of 5HM is suppressed, resulting in the fixation of the M enantiomer. This explanation may be supported by a 1 H-NMR study 15 which demonstrated that a guest molecule in small-sized vesicles rotates more rapidly than that in large-sized vesicles.…”