Repelling disorder: What makes cholesterol-containing surfaces so repulsive?

Living organisms use powerful physical principles to control interactions at their surfaces. Researchers at the Leibniz Institute of Polymer Research Dresden, Leipzig University and TU Dresden have now discovered why cholesterol-containing surfaces can exhibit greatly reduced attachment of proteins and bacteria.

A close up of a blue beetle on a green and brown natural surface — The Collembola Tetrodontophora bielanensis in its natural habitat © Leibniz Institute of Polymer Research Dresden/Stephan Floss

The interdisciplinary team led by Carsten Werner had previously identified cholesterol as a component of the skin of widespread invertebrates (collembolae), which breathe through their skin and therefore need to protect it from contamination. In their paper published in Nature on June 22, 2023, the scientists have now elucidated a repulsive mechanism of cholesterol-containing surfaces. Using experiments, simulations and thermodynamic analyses, they were able to show how the spontaneous change in the orientation of interfacial cholesterol molecules creates an "entropic barrier" that makes cholesterol-containing surfaces repellent.

The development of synthetic materials using the discovered principle is promising, as it is important for many products and technologies to effectively minimize the attachment of biomolecules and bacteria. However, such “translation” of the effect to scalable, robust surface functionalization requires further research.

At the Leibniz Institute of Polymer Research Dresden (IPF), basic principles for new materials and their application in future technologies are being developed, with biology-inspired material concepts becoming increasingly important. The Chair of Biophysical Chemistry at Leipzig University works closely with the IPF on biomimetic materials. At the Cluster of Excellence Physics of Life of the TU Dresden, basic principles of the functionality of living matter are being explored.

Jens Friedrichs¹, Ralf Helbig¹, Julia Hilsenbeck¹, Prithvi Raj Pandey², Jens-Uwe Sommer^2,4, Lars David Renner¹, Tilo Pompe^1,3 und Carsten Werner^1,4,5
Entropic repulsion of cholesterol-containing layers counteracts bioadhesion. Nature doi.org/10.1038/s41586-023-06033-4 (2023)

¹ Institute of Biofunctional Polymer Materials, Leibniz Institute of Polymer Research Dresden, Germany
² Institute of Theory of Polymers, Leibniz Institute of Polymer Research Dresden, Germany
³ Institute for Biochemistry, Leipzig University, Germany
⁴ Cluster of Excellence Physics of Life, Technische Universität Dresden, Germany
⁵ Center for Regenerative Therapies Dresden, Technische Universität Dresden, Germany

Contact: Prof. Dr. Carsten Werner, werner@ipfdd.de

Source: IPF