Biophysical Society Thematic Meeting | Bucharest 2026

Biophysics of Membrane Reactions in Brian

Poster Abstracts

5-POS

Board 5

ELECTROKINETIC EFFECTS ON AMYLOID BETA TRANSPORT WITHIN POROUS PERIVASCULAR SPACES Jaemin Kim; Soonmoon Jung; Youngho Lee; Hyeyeong Song; Kyunghun Noh; Youngjae Park; Junghwa Hong ; Korea University, Dept. of Control and Instrumentation Engineering, Sejong, South Korea Perivascular spaces (PVS) that encircle cortical blood vessels provide a route for cerebrospinal fluid (CSF) exchange with the brain, supporting the clearance of solutes such as amyloid beta (A β ). Many previous studies have treated PVS as either an open channel or an extracellular matrix (ECM)-based porous medium while neglecting electrical effects, largely justified since CSF, as an electrolyte at physiological ionic strength, has a very short Debye length ( λ D). However, transmission electron microscopy observations reveal that the PVS is partitioned by pia- and arachnoid-derived cellular processes and basket-like trabecular networks (Lam et al., 2017; Mestre et al., 2022). Since this dense porous architecture satisfies the length scale condition (H) significantly affecting anionic polyelectrolytes like A β , this study defines H as the effective pore scale determined by trabecular structures rather than the macroscopic channel width. Consequently, we derived and incorporated a permeability–streaming potential correlation dependent on κ H. This relationship indicates that decreasing porosity increases hydraulic resistance while simultaneously strengthening the streaming potential-induced electric field, nonlinearly amplifying A β electrophoretic transport. The model was configured as a concentric double-cylinder domain with a porous PVS channel of 8 µm in width between the brain parenchymal boundary (outer wall) and the arteriolar vessel wall (inner wall). To focus on fluid– electric interactions without accounting for vascular wall deformation, radial wall displacements were specified as boundary conditions, fully coupling Brinkman flow with Poisson–Nernst– Planck ion transport. In the high-permeability (open) model, weak streaming potentials limited electrophoretic acceleration, yielding a mean speed of approximately 20 µm/s. Conversely, the dense porous model generated stronger streaming-potential fields under increased hydraulic resistance, resulting in a 3.8% higher mean transport speed. These results quantitatively suggest that, even under flow-constraining porous conditions, the electrophoretic component driven by streaming-potential-induced electric fields can electrokinetically enhance A β transport.

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