Dr. Richard Campbell
Photo Credit: Courtesy of University of Manchester
Scientific Frontline: Extended "At a Glance" Summary: Fibrinogen Self-Assembly
The Core Concept: Fibrinogen, a key blood-clotting protein, forms multiple flat layers when it contacts air, rather than a single tilting layer as previously thought.
Key Distinction/Mechanism: Instead of molecules laying flat initially and then standing upright as more arrive (the "single tilting layer" model), fibrinogen molecules remain flat and stack upon one another like sheets of paper, growing thicker and more complete as concentration increases.
Major Frameworks/Components:
- Fibrinogen: The protein responsible for forming fibrin fibers, which constitute the basis of a scab during blood surface fluid evaporation.
- Neutron Reflectometry: An advanced technique utilized at the Institut Laue-Langevin (ILL) to observe the precise structure of protein surfaces at a microscopic level.
- Fibrin: Fibers formed from fibrinogen that act as the foundation for scabs, sealing wounds.
Branch of Science: Biochemistry, Biophysics, and Hematology.
Future Application:
- Development of advanced treatments for clotting disorders like hemophilia.
- Improved clinical management for patients taking blood thinners such as warfarin.
- Enhanced design of biosensors for monitoring blood performance.
- Better understanding and potential treatments for acute respiratory distress syndrome (ARDS), where fibrinogen disrupts airway-maintaining oily layers.
Why It Matters: Accurate knowledge of how scabs form at the air-water interface is essential for understanding wound healing, managing clotting-related conditions, and developing novel medical interventions and diagnostic tools.
Scientists have redefined how the key blood-clotting protein fibrinogen behaves when it contacts air, overturning two decades of scientific consensus on wound healing.
It is the culmination of over a decade of international collaboration by Dr. Richard Campbell of The University of Manchester, Professor Juan Ruso of the University of Santiago de Compostela in Spain, and Dr. Natalia Hassan of the Metropolitan Technological University in Chile.
The discovery could have far-reaching implications for the treatment of clotting disorders like hemophilia or the healthcare of patients on blood thinners like warfarin, as scabs forming on the surface of blood are vital to sealing a wound and keeping the site free of infection.
It could also explain aspects of how a lung can collapse in acute respiratory distress syndrome (ARDS), as fibrinogen disrupts the oily layer that keeps the airways open during breathing.
It may also transform the design of biosensors that allow people to monitor how their blood is performing, as the sensors rely on understanding how proteins disrupt those surfaces.
For more than twenty years, the field has relied on a "single tilting layer" model for fibrinogen, where the long protein molecules lie flat on the surface at first and then lean upright as more of them arrive.
But the new study, published in the Journal of the American Chemical Society on August 20, 2025, shows that the benchmark model missed that fibrinogen remains flat and builds multiple layers that stack like sheets of paper. These layers grow thicker and more complete as more molecules arrive.
This new information helps to explain how the long protein molecules line up on the surface of blood, where fibers called fibrin form the basis of the scab—a solid film formed during the evaporation of fluid at the blood surface that seals a wound.
The scientists used an advanced technique called neutron reflectometry at the part-UK-funded Institut Laue-Langevin (ILL) in France, where Dr. Campbell was formerly based.
The team demonstrated that this behavior holds true across multiple ranges of concentration and in very different solution conditions, showing that the mechanism is not a rare quirk but a universal feature of fibrinogen when it contacts air.
Principal investigator Dr. Campbell explained, "It's never easy challenging an established model of how molecules behave in nature.
"But through using the advanced technique of neutron reflectometry on the FIGARO instrument at the ILL research facility, we could see the structure of these protein surfaces in more detail than scientists had seen before.
"Although lab data recorded in the past were compatible with the concept of a 'single tilting layer' model, our new data show multiple layering as a fundamentally different way of working."
Dr. Glenn Coope, a former PhD student at The University of Manchester but now based at Lund University in Sweden, said, "When the COVID-19 pandemic struck, I spent time working from home analyzing structural data on how fibrinogen gathered at liquid surfaces.
"Then, after returning to work at the university, I applied additional experimental methods.
"It’s almost like we now have a full-circle moment, as our findings may help scientists to better understand the behavior of fibrinogen in the lungs of patients suffering from ARDS, a condition that tragically claimed so many lives during the pandemic."
Dr. Campbell added, "Our discovery sheds new light on how scabs form on the surface of an open wound, where fibrinogen works in a protein-rich zone to stop bleeding.
"Having a better understanding of the structure of fibrinogen at liquid surfaces can only help in the search for new and better treatments for patients whose wounds refuse to heal."
Published in journal: Journal of the American Chemical Society
Authors: Glenn J. Coope, M. Jayne Lawrence, Philipp Gutfreund, Natalia Hassan, Juan M. Ruso, and Richard A. Campbell
Source/Credit: University of Manchester | Michael Addelman
Edited by: Scientific Frontline
Reference Number: bchm082026_01