[The relationship between the mechanical and electrical properties of a synthetic hydrogel chosen as an experimental model of cytoskeleton].
A correlation between the electrochemical (Donnan) potential and volume swelling has been studied for synthetic polyelectrolyte hydrogels considered as models of cytoskeleton gel-forming biopolymers. Hydrogels based on polyacrylic and polymethacrylic acids with varying network density have been synthesized by radical polymerization in water solution. Electric charge was introduced into the gel network by partial neutralization of acidic monomers by alkali and alkali-earth (hydr)oxides. The electrochemical (Donnan) potential of synthetic gels was measured by a conventional microelectrode technique used in studies of cell potential. It was shown that the negative electric potential became lower as the equilibrium swelling degree decreased for a large number of anionic gels with varying electric charge and network density, i.e., the content of water in the gel decreased. It was shown that the abrupt phase transition of hydrogel structure from a swollen to a contracted state under the influence of K+/Ca2+ ionic exchange is accompanied by a similar decrease in absolute values of the Donnan potential of the gel. A kinetic study showed that volume changes went prior to the decrease in electric potential. This suggests that the volume phase transition in gel structure is the major cause for the electric response. A similarity was shown between the swelling/collapse phase transition in the gel and volume changes in cytoskeleton beneath the cell membrane. Based on the universal properties of synthetic and biopolymer hydrogels, a possible swelling-induced mechanism of cell electrical potential regulation is proposed.
Shkliar
T F
TF
Safronov
A P
AP
Kliuzhin
I S
IS
Pollack
G H
GH
Bliakhman
F A
FA
D002118:Calcium / Q000737:chemistry; D002413:Cations, Divalent; D003599:Cytoskeleton; D004563:Electrochemistry; D020100:Hydrogels; D055595:Mechanical Phenomena; D008954:Models, Biological; D011109:Polymethacrylic Acids / Q000737:chemistry*
D002413:Cations, Divalent; D020100:Hydrogels; D011109:Polymethacrylic Acids; C030613:polymethacrylic acid; D002118:Calcium