Seeing inside wound dressings with neutrons

Mölnlycke Healthcare is a world-leading MedTech company that specializes in innovative solutions for wound care and surgical procedures. The company offers a wide range of products, including absorbent foam dressings designed to aid and improve the healing process for various types of wounds. By collaborating with researchers from RISE and Lund University, Mölnlycke Healthcare aims to improve wound care methods, especially as society faces a major challenge with hard-to-heal wounds in an aging population.

Followed the movement of the fluid in real time

To gain a deeper understanding, the research team chose to use neutron-based imaging, specifically Neutron Radiography (NR) and Neutron Computed Tomography (NCT). These techniques are ideal for studying how fluids move in materials without destroying or changing the fluids. Unlike regular X-rays, which use X-ray beams and contrast fluids, neutrons can provide better images of fluids in materials, such as horse serum, which is similar to the fluids found in real wounds. Neutrons also interact strongly with hydrogen, making it easier to see fluids that are hard to detect with other methods. Another advantage of neutron-based imaging is that it allows real-time tracking of the fluid’s movement. This means researchers can see how the fluid spreads inside the material over time. This information is important for understanding how well a wound dressing works in real-world situations, which is key to developing better and more effective products.

In the study, two different types of wound dressings were evaluated: 

•  Polyurethane (PUR) foam.
• Fiber material with superabsorbent particles (SAP).

To create realistic test conditions, two different fluids were used: 

• A saline solution.
• Horse serum, which mimics wound fluid.

A form of water where hydrogen atoms are replaced with deuterium, a variant of hydrogen, was used in the fluid to reduce neutron absorption. A liquid pump adjusted the flow rate to simulate the flow rate in chronic wounds was used. The experiments were carried out at the NeXT neutron imaging beamline at ILL (Institut Laue-Langevin) in Grenoble, France, over a period of 48 hours. Both 2D real-time images and 3D tomographic images were taken to study the fluid distribution through the dressings.

What did the study show?

The study showed that using horse serum mixed with deuterium oxide gave the best results in Neutron Radiography. This method allows for a realistic assessment of how wound dressings handle fluids under clinical conditions, meaning in real-world environments, which contributes to the development of better wound care products. RISE’s contribution, by developing and implementing image processing and analysis protocols, was crucial in the fluid transport analysis and ensuring that the method provides reliable and useful results. The results also highlight how important it is to use relevant test fluids when developing wound products, as traditional tests with saline solutions don’t always provide the correct information on how well the dressings perform with biological fluids. This study lays the foundation for future research and innovations in wound care and improved testing methods for wound dressings.