Beneficial effect of the physical properties of cholesteric liquid crystals on the membrane of biological cells

Abstract

The physical properties of cholesterol (cholesteric liquid crystal) ensure the correct packaging of the
phospholipid part of the membrane, which is necessary for its normal operation, affecting on the
mobility of the fatty acid tails of membrane lipids: if the membrane is too rigid and there is a danger
of "freezing" fatty acid chains, cholesterol causes them to liquefy, since chains in his presence become
more mobile; if the membrane is too “liquid”, then cholesterol thickens it.
A number of authors explain this sealing effect of cholesteric liquid crystal (cholesterol) by the fact
that the cholesteric liquid crystal (cholesterol), containing in the biological membrane, due to its
physical properties, reduces the slope of hydrocarbon phospholipid tails, located not perpendicular to
the membrane plane, but at a certain angle.
The physical properties of cholesterol thus increase the elasticity and mechanical strength of the
bilayer of bipolar phospholipids of membrane cell, due to which the membrane can change its shape
in response to the force applied to it.
The physical properties of cholesterol control the permeability of the bipolar phospholipids bilayer of
the biological cell membrane. At temperatures above the phase transition of phospholipids,
cholesterol has a condensing effect (a decrease of the area, occupied by a phospholipid molecule),
reduces the rate of diffusion of phospholipids in the bilayer, and reduces the permeability of the
bipolar phospholipid bilayer of membrane cell by water molecules and ions.
At temperatures below the phase transition of phospholipids, cholesterol increases the area, occupied
by the phospholipid molecule, increases the rate of diffusion of phospholipids in the bilayer, and
increases the permeability of the bipolar phospholipid bilayer of membrane cell by water molecules
and ions.
The article presents a theoretical description of the beneficial influence of the physical properties of a
cholesteric liquid crystal (cholesterol) on the membrane of biological cells, which plays a vital role in
biological cells.
It will be shown how the physical properties of cholesterol or cholesteric liquid crystal, located in the
membrane of a biological cell, placed in a solution of a negatively charged catholyte, sharply increase
the permeability of the bipolar phospholipid bilayer of the biological membrane cell by water
molecules and ions through the cholesteric liquid crystal or cholesterol into the inside of the biological
cell due to in this case, an increase of the positive electrostatic potential of the outer layer of the
bipolar phospholipid bilayer, which contributes to the adoption by a cholesteric liquid crystal or
cholesterol of a configuration with open gaps in relation to the environment (catholyte solution of
nutrient media) between its monolayers, and thereby accelerating the exchange processes between the
cell and its environment, contributing to its rapid reproduction.
It will also be shown that the physical properties of cholesterol or cholesteric liquid crystal, located in
the membrane of a cancer cell, placed in an aqueous solution of a positively charged anolyte, prevent
the penetration of water molecules and ions through cholesterol or cholesteric liquid crystal into the

inside of the cancer cell by reducing the positive electrostatic potential of the external layer of the
bipolar phospholipid bilayer to zero, which contributes to o the adoption by a cholesteric liquid crystal
or cholesterol of a configuration with close gaps in relation to the environment (anolyte solution)
between the monolayers of cholesteric liquid crystal or cholesterol in the bipolar phospholipid bilayer
of the cancer cell membrane, which stops the exchange of the cancer cell with the environment,
leading to its death.