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Researchers Sebastian Busch, Christoph Smuda, Luis Carlos Pardo and Tobias Unruh have discovered using neutron spectroscopy techniques that the molecules of a cell membrane do not move at random as previously believed, but rather in a flowing motion as suggested by various computer simulations. The discovery has a major impact on the regeneration of cell membranes and the biological mechanisms that involve membrane proteins.

The human body is formed by cells whose ‘skin’ consists of a phospholipid membrane with amphipathic molecules that can repel and absorb water. This property enables them to self-organize into cell walls, in a manner similar to bricks being thrown in water and then moving to form the walls of a house. The membrane also has a surprising ability to regenerate itself. According to Luis Carlos Pardo, a researcher at the Department of Physics and Nuclear Engineering of the UPC-Barcelona Tech, “although the molecules that form the membrane are huge in relative terms, they have the uncanny ability to move and this is precisely what is responsible for the self-healing process. Imagine the bricks of a house being able to rebuild a broken wall”.

The research team of the UPC-Barcelona Tech’s Materials Characterization Group has devised a Bayesian analysis method (fitting algorithm for Bayesian analysis of data, FABADA) that has refuted the idea that membrane molecules move chaotically by diffusion. Instead, the team has discovered that they form currents that run through the cell membranes like a river. “This means that their small-scale mobility is greater than previously thought”, says Professor Pardo, a member of the team at the UPC-Barcelona Tech’s Nanoengineering Research Center.

Phospholipid cell membranes are a very interesting area of research due to their natural abundance (every human body contains several square kilometers) and their pharmaceutical applications.

Cell membranes were largely unknown until just over a decade ago, when the development of nanotechniques yielded detailed information on their structure. Nevertheless, their movement dynamics remained a mystery that did not begin to be solved until the discovery of neutron spectroscopy, a technique that uses a beam of neutrons to reveal the properties of certain materials and for which Bertram Brockhouse was awarded the Nobel Prize in Physics in 2004.