Thanks to research undertaken by the University of Leeds, a super-lubricant made entirely of potato proteins may open the door to sustainable industrial and biomedical applications.

The innovative aqueous substance, according to the team, can produce extreme lubricity or almost zero friction by imitating biological processes like the synovial fluids that articulate cartilage in human joints.

“Engineering an eco-friendly, efficient, and functional aqueous lubricant has eluded researchers until now. Many, if not most, aqueous lubricants use materials that are nearly exclusively derived from synthetic chemistry,” according to ‘Self-assembly of sustainable plant protein protofilaments into a hydrogel for ultra-low friction across length scales’ paper published by the Nature website.

The interdisciplinary team used alternative proteins, like potato protein, as eco-friendly building blocks that can be naturally sourced as a by-product and have a lower carbon footprint. The team included researchers from the University of Leeds School of Food Science and Nutrition, the Weizmann Institute of Science in Israel, King’s College London, and INRAE, France. Their study’s findings are now available in the journal Communications Materials.

“This is a revolutionary material engineering paradigm for biomedical applications and is a key milestone towards achieving highly sustainable, plant-based aqueous lubricant materials. What we have done is create a self-assembly of plant protein-based protofilaments with biopolymeric hydrogels in a patchy architecture. Combining multi-scale experimental measurements with molecular dynamics simulations, our unprecedented results reveal how a self-assembly can be fabricated using plant proteins to deliver super lubricity via hydration lubrication,” Lead author, Anwesha Sarkar, who is a Professor of Colloids and Surfaces in Leeds’ School of Food Science and Nutrition, said.

First author Olivia Pabois, Postdoctoral Fellow in Leeds’ School of Food Science and Nutrition, added that what she and her colleagues have created could well be the ‘next generation of engineered biomedical materials’ for uses such as artificial synovial fluid, tears, and saliva.

“It could also be used for low-calorie foods where you can achieve low-fat items without compromising the fatty feel of higher fat content counterparts,” Pabois mentioned.

The researchers studied the surface morphology and nanotribology of the lubricants using facilities at the Weizmann Institute of Science in Israel, where they had access to cutting-edge methods for detecting surface forces.

“The publication of this exciting work is the culmination of contacts with Professor Sarkar which started in 2019 and is an excellent example of international collaboration where the overall achievement is significantly greater than the sum of its parts,” Professor Jacob Klein added.

“As part of this interdisciplinary team led by Professor Sarkar, we were able to combine our expertise in molecular dynamics simulations with the experimental expertise of the other groups to link the molecular scale details of this exciting plant protein-based lubricant to its amazing lubrication properties. As a result, by being able to quantify the interactions that govern the assembly of the plant proteins and the hydrogel, as well as the absorption of this lubricant onto surfaces, we open the doors to potentially unlocking the ability to rationally design self-assembled structures of natural materials that optimize their lubrication properties,” Professor Chris Lorenz from King’s College London commented.

“I was very happy to contribute to this promising study that aligns perfectly to INRAE’s objectives of laying the basis for a sustainable bio-based economy, replacing fossil-fuel-based materials and energies with their biomass-based counterparts,” Dr. Marco Ramaioli from INRAE France concluded.