Biophysical Society Thematic Meeting | Riga 2026

Active and Responsive Soft Matter: From Biological to Engineered Systems

Wednesday Speaker Abstracts

STRUCTURE, REORGANIZATION, AND ROBUSTNESS OF LARGE MULTINUCLEATED CELLS Mason Miguel 1 ; Caroline Barotta 1 ; Brian Freedman 1 ; David Merges 1 ; Hannah Yevick ; 1 Brandeis University, Physics, Waltham, MA, USA The outer layer of the placenta is a single cell that reaches the striking size of around 13m 2 at term. A healthy pregnancy relies on the mechanical integrity of this huge cell, the syncytiotrophoblast. Preeclampsia, for example, which impacts 1 in 25 pregnancies correlates with defects in syncytial structure and function. Multicellular tissues are rigidified through cell cell junctions that anchor cytoskeletal filaments around the perimeter of the cell and across the cell’s surface. Syncytial cells possess an undivided cytoplasm and lack these anchoring points. I will describe our efforts to understand how syncytial mechanics changes with syncytial size. We express a viral fusogenic protein in our cells to control syncytial formation from micron 2 to the centimeter 2 sizes. We have identified that large syncytia internally organize “supracellular sized” structures that influence their mechanics. Syncytial size also impacts how robust a cell is to damage. Identifying how the syncytiotrophoblast maintains its physical integrity is relevant for preventing and treating placental defects. More broadly, understanding the link between multinucleation and a cell’s mechanical properties is relevant in diverse tissues, as multinucleation is triggered during disease and aging.

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