DYNAMICS OF PORE GROWTH IN MEMBRANES AND MEMBRANE STABILITY

Pores can form and grow in biomembranes because of factors such as the rmal fluctuation, transmembrane electrical potential, and cellular env ironment. We propose a new statistical physics model of the pore growt h treated as a non-Markovian stochastic process, with a free energy ba rrier and memory friction from the membrane matrix treated as a quasi- two-dimensional viscoelastic and dielectric fluid continuum. On the ba sis of the modern theory of activated barrier crossing, an analytical expression for membrane lifetime and the phase diagram for membrane st ability are obtained. The memory effect due to membrane viscoelasticit y and the elasticity due to cytoskeletal network are found to induce s harp transitions to membrane stability against pore growth and compete with other factors to manifest rich dynamic transitions over the memb rane lifetime.