EFFECTS OF HYALURONAN VISCOUS MATERIALS ON CELL-MEMBRANE ELECTRICAL-PROPERTIES

Hyaluronan [hyaluronic acid (HA)] has been implicated in various cellu lar processes such as proliferation, adhesion, migration, and differen tiation. The secondary and tertiary structures of KA give it very impo rtant and unique viscoelastic properties. HA-composed materials are cu rrently used intraocularly during ophthalmological surgery to facilita te surgical procedures and prevent tissue damage. To examine the effec ts of three viscous biomaterials composed of hyaluronan (Healon(TM), I AL(TM), and Biolon(TM)) used in ophthalmological surgery, the membrane electrical properties of the erythroleukemic K562 cell line exposed t o these materials were investigated. Membrane conductivity, membrane p ermittivity, and the conductivity of the cytosol were evaluated using dielectric relaxation measurements in the radiofrequency range and fit ting the experimental results to the general equations of the Maxwell- Wagner effect. The results demonstrate that while membrane permittivit y and the conductivity of the cytosol are not significantly altered, t he membrane conductivity of K562 cells exposed to all three biomateria ls increases substantially and in a time-dependent manner with respect to untreated cells. These observations seem to indicate that hyaluron an perturbs ionic transport while it does not vary the type, quantity, or distribution of membrane components. In addition, the variations i nduced 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. (C) 1998 John Wiley & Sons, Inc.