Membrane processes and biophysical characterization of living cells decorated with chromatic polydiacetylene vesicles

Abstract

The structural complexity of the cell membrane makes analysis of membrane processes in living cells, as compared to model membrane systems, highly challenging. Living cells decorated with surface-attached colorimetric/fluorescent polydiacetylene patches might constitute an effective platform for analysis and visualization of membrane processes in situ. This work examines the biological and chemical consequences of plasma membrane labeling of promyelocytic leukemia cells with polydiacetylene. We show that the extent of fusion between incubated lipid/diacetylene vesicles and the plasma membrane is closely dependent upon the lipid composition of both vesicles and cell membrane. In particular, we find that cholesterol presence increased bilayer fusion between the chromatic vesicles and the plasma membrane, suggesting that membrane organization plays a significant role in the fusion process. Spectroscopic data and physiological assays show that decorating the cell membrane with the lipid/diacetylene patches reduces the overall lateral diffusion within the membrane bilayer, however polydiacetylene labeling does not adversely affect important cellular metabolic pathways. Overall, the experimental data indicate that the viability and physiological integrity of the surface-engineered cells are retained, making possible utilization of the platform for studying membrane processes in living cells. We demonstrate the use of the polydiacetylene-labeled cells for visualizing and discriminating among different membrane interaction mechanisms of pharmaceutical compounds.

Screening Membrane Interactions of Pesticides by Cells Decorated with Chromatic Polymer Nanopatches

“…Previous reports pointed to fluidity changes in lipid bilayers as a major consequence of binding by membrane-active pharmaceutical molecules, short peptides, and insecticides as well (3,48,49). Moreover, modification of bilayer ordering and fluidity induced by membrane-active molecules was shown to constitute a primary factor contributing to the chromatic transitions in PDA-labeled cells (12). Accordingly, the fluorescence anisotropy data in Figure 4 support the direct relationship between the bilayer perturbation induced by the putative membrane-active pesticides and the fluorescence transformations in the PDA-labeled cells.…”

“…Here, we demonstrate a new approach for evaluation and rapid screening of pesticide interactions with the plasma membrane through application of a recently developed living-cell membrane sensor − . The experimental platform comprises live mammalian cells in which the plasma membrane has been decorated with polydiacetylene (PDA) nanopatches .…”

The application of polymerized lipid vesicles as colorimetric biosensors for real-time detection of pathogens in drinking water

“…The use of chromatic vesicles in liquid samples for the detection of bacteria is very difficult because the vesicles are not specific and react with many chemicals, including detergents (Kolusheva et al 2000a;Kolusheva et al 2000b;Jelinek and Kolusheva 2001;Kolusheva et al 2001;Orynbayeva et al 2007;Groysman et al 2008;Sokolovski et al 2008).…”

Cell‐surface sensors: lighting the cellular environment

“…One excellent example is chromatic polydiacetylene (PDA) 66. Jelinek and coworkers have used PDA nanopatches to monitor the biophysical processes of cell membrane 12,67. The conjugated PDA nanopatches they fused on the cell membrane exhibited an intense blue color.…”

“…During this blue‐to‐red color transition, the initial non‐fluorescent PDA also emitted fluorescence at 560 and 640 nm. The PDA nanopatches can therefore be used to detect cell bilayer perturbing agents including lidocaine, polymyxin‐B, cholesterol, and oleic acid, and to screen toxic pesticides and other environmentally sensitive small molecules 12,67,68…”