SFB1551 Group Leader Andreas Walther, Postdoctoral Researcher Weixiang Chen from the Life-Like Materials and Systems from the Chemistry department at JGU Mainz, and collaborators from the Max Planck Institute for Polymer Research have just discovered a brand-new diffusion mechanism in biomolecular condensates. Their study, now published in Nature Nanotechnology, reveals ballistic wave diffusion — a unique transport mode where ultrasharp molecular fronts move forward in a straight, linear fashion.

Why does it matter?
This discovery is exciting because it connects the physics of polymers with the biology of cells, showing how the structure and dynamics of biomolecular condensates shape the way molecules move. It offers a possible explanation for the sharp diffusion fronts observed in living systems and points toward new ways of controlling molecular gating in both synthetic and biological contexts.

Biomolecular condensates in cells compartmentalize vital processes by enriching molecules through molecular recognition. However, it remains elusive how transport occurs in biomolecular condensates and how it relates to their dynamic and/or viscoelastic state. We show that the transport of molecules in DNA model condensates does not follow classical Fickian diffusion, which has a blurry front with a square root of time dependence. By contrast, we identify a new type of transport with an ultrasharp front that propagates linearly with time. Our data reveal that this ultrasharp ballistic diffusion front originates from molecular recognition and an arrested-to-dynamic transition in the condensate properties. This diffusion mechanism is the result of intertwining chemical kinetics and condensate dynamics on transport in biomolecular condensates. We believe that our understanding will help to better explain and tune the dynamics and properties in synthetic condensate systems and for biological functions.