Effects of hyaluronan viscous materials on cell membrane electrical properties

Abstract

Hyaluronan [hyaluronic acid (HA)] has been implicated in various cellular processes such as proliferation, adhesion, migration, and differentiation. The secondary and tertiary structures of HA give it very important and unique viscoelastic properties. HA-composed materials are currently used intraocularly during ophthalmological surgery to facilitate surgical procedures and prevent tissue damage. To examine the effects of three viscous biomaterials composed of hyaluronan (Healon, IAL, and Biolon) used in ophthalmological surgery, the membrane electrical properties of the erythroleukemic K562 cell line exposed to these materials were investigated. Membrane conductivity, membrane permittivity, and the conductivity of the cytosol were evaluated using dielectric relaxation measurements in the radiofrequency range and fitting the experimental results to the general equations of the Maxwell-Wagner effect. The results demonstrate that while membrane permittivity and the conductivity of the cytosol are not significantly altered, the membrane conductivity of K562 cells exposed to all three biomaterials increases substantially and in a time-dependent manner with respect to untreated cells. These observations seem to indicate that hyaluronan perturbs ionic transport while it does not vary the type, quantity, or distribution of membrane components. In addition, the variations induced by these substances on the cell membrane are not dependent upon the molecular weight or on the biological origin of hyaluronan. These results may aid in elucidating the mechanisms involved in hyaluronan/cell membrane interaction and thus may provide a deeper understanding of the complications related to their use in ophthalmological surgery.

Adsorption of Glycosaminoglycans to the Cell Surface Is Responsible for Cellular Donnan Effects

“…Glycosaminoglycans behave like ion exchangers and impede free diffusion of counterions [Wu, 1926;Maroudas, 1968]. Hyaluronan as a fixed ion exchanger may explain its influence on the electrical impedance of the cerebellum [Wang and Adey, 1969] and other electrical properties of cell membranes [Santini et al, 1998]. It could also serve as the hitherto unknown matrix on the surface of neurons for long-term memory [Kochlamazashvili et al, 2010] which involves storage of charges upon electrical stimulation and local hyperpolarisation, that is, potassium efflux, and subsequent delayed influx of calcium ions [Baudry et al, 2011].…”

“…Annihilation of the membrane potential reduced glycosaminoglycan binding, but a basal level of concentration‐dependent adsorption remained even in HEK cells. The residual adsorption could be hydrophobic interactions or hydrogen bridges with cell surface components [Scott et al, ] and ionic interactions with cell surface proteins [Angello and Hauschka, ; Santini et al, ; Annabi et al, ; Lord et al, ]. Adsorption of glycosaminoglycans occurred in two cell types suggesting that it is a general phenomenon independent of cell‐specific parameters such as surface area and receptor specificities.…”