(314h) Adhesive Dynamics of Lubricated Membranes

Membrane waves have been observed near the leading edge of a motile cell. Such phenomenon is the result of the interplay between hydrodynamics and adhesive dynamics. In this study, we model membrane behavior on a thin fluid gap supported by adhesive bonds, using lubrication theory and adhesive dynamics. The model yields traveling wave solutions to four adhesion scenarios, namely no adhesion, uniform adhesion, clustered adhesion and focal adhesion. The resulting traveling waves are observed to depend strongly on adhesion and they could be classified as either tension or adhesion waves. In contrast to tension waves, adhesion waves show characteristically amplified peaks and are highly persistent. The transition of tension to adhesion waves is found to depend on a necessary but insufficient criterion. Further analysis shows that strong adhesion leads to dispersion in tension waves but amplification in adhesion waves, resulting in sharp tension to adhesion wave transition points. The present work could explain the strong persistence of the waves observed in adhered cells using differential inference contrast (DIC) microscopy and the observation that the wavelengths decrease shortly after leading edge retraction.