The Koslover Group Department of Physics, UCSD

Emergent Physics of Soft Matter within Living Cells

A cell is an immensely complex system that transforms myriads of interacting molecules into a living entity. While it is often helpful to imagine the cell as an amorphous bag of macromolecules or as a wiring diagram of molecular interactions, each cell is a fundamentally physical object, and it is the physical properties of cells that form the focus of our group. Cells are made up primarily of active soft matter -- materials that are flexible enough to respond to thermal fluctuations, while being constantly bombarded by actively generated out-of-equilibrium forces. The behavior of such materials is often non-intuitive and the governing physical principles are only now beginning to be understood. Research in the Koslover group is centered on the multi-scale physics of intracellular soft matter, from biopolymers, to membranes, to fluids. We develop and implement analytical and computational techniques grounded in statistical physics, continuum mechanics, and fluid dynamics, to understand how collective physical phenomena arise from biomolecular constituents and how they are harnessed for cellular function.

Trajectories of small acidified particles in the cytoplasm of a motile, deforming neutrophil-like cell.

Coarse-grained models of the statistical mechanics of semiflexible DNA in complex with bound proteins.

Example trajectory of a multimodal search process including 3D hops and 1D sliding events.