Modulation of Membrane Fluidity Performed on Model Phospholipid Membrane and Live Cell Membrane: Revealing through Spatiotemporal Approaches of FLIM, FAIM, and TRFS

Abstract

We have elucidated the role of unsaturated fatty acid in the in vitro model phospholipid membrane and in vivo live cell membrane. Fluorescence microscopy and time-resolved fluorescence spectroscopy have been employed to uncover how modulation of vesicle bilayer fluidity persuades structural transformation. This unsaturation induced structural transformation due to packing disorder in bilayer has been delineated through spatially resolved fluorescence lifetime imaging microscopy (FLIM) and fluorescence polarization or anisotropy imaging microscopy (FPIM/FAIM). Structure–function relationship of phospholipid vesicle is also investigated by monitoring intervesicular water dynamics behavior, which has been demonstrated by temporally resolved fluorescence spectroscopy (TRFS) techniques. Nevertheless, it has also been manifested from this study that loss of rigidity in bilayer breaks down the strong hydrogen bond (H-bond) network around the charged lipid head groups. The disruption of this H-bond network increases the bilayer elasticity, which helps to evolve various kinds of vesicular structure. Furthermore, the significant influence of unsaturated fatty acid on membrane bilayer has been ratified through in vivo live cell imaging.

A Comparative Study on DMSO-Induced Modulation of the Structural and Dynamical Properties of Model Bilayer Membranes

“…This means that, due to the unsymmetrical packing of the lipid molecules, the lipid bilayers transform into the pear/rod-shaped structure. As a result, the rigid water structure ruptures and the probe molecules have more freedom to diffuse easily with lower diffusion time scales; thus, the diffusion constants of DCM increase in the presence of DMSO …”

“…As a result, the rigid water structure ruptures and the probe molecules have more freedom to diffuse easily with lower diffusion time scales; thus, the diffusion constants of DCM increase in the presence of DMSO. 81 Effect of DMSO on the Fatty Acid Vesicle Having Different Headgroups. Now, we are interested in investigating the effect of DMSO on a fatty acid vesicle, which is a nonphospholipid vesicle.…”

Photochemically Induced Cyclic Morphological Dynamics via Degradation of Autonomously Produced Self-Assembled Polymer Vesicles

“…2a and supplementary movie 1, upon irradiation, a phase rich in the dye, R6G, with bright uorescence emission gradually separated from the water phase and ultimately occupied the entire image eld. Given the a nity between the dye and the PHPMA-blocks 31,32 , the observed phase separation can be argued to result from gelation which eventually lled the image eld with the hydrophobic phase containing PHPMA blocks and HPMA.…”

Modulation of Membrane Fluidity to Control Interfacial Water Structure and Dynamics in Saturated and Unsaturated Phospholipid Vesicles

“…This fast rotational decay time indicates that the unsaturation in the long tail forms less rigid H-bond interiors of vesicles because a double bond can produce a kink in the alkane chain, resulting in a disruption in the lipid packing. 57 This disruption creates extra free space within the vesicle bilayer that allows additional flexibility in the adjacent alkane chains. Therefore, unsaturation in phospholipid chain results in increased fluidity in the bilayer.…”