Triple publication success for bachelor’s theses

Seeing a bachelor’s thesis published in a scientific journal is relatively uncommon. For three theses linked to the same research group to result in scientific publications within just three months is downright rare. Yet that is exactly what has happened in Elsebeth Schröder’s research group at the Division of Quantum Device Physics.
To celebrate the milestone, Elsebeth invited all three student teams to a cake party at the Department of Microtechnology and Nanoscience.

"It feels fantastic, of course. I certainly wasn’t expecting this," says Alva Limbäck, whose article A density functional theory study of amino acids on pristine Mg(0001) and with sparse alloying elements was published in Applied Surface Science in August, together with fellow students Olof Hildeberg, John Bolin and Amanda Goold.

Aiming to improve biodegradable implants

All three theses explore how magnesium implants interact with the biological environment of the human body. Unlike implants made from titanium or steel, magnesium is biodegradable, meaning it can gradually dissolve and be absorbed by the body once it has fulfilled its purpose. Such implants are already being used clinically, although still on a limited scale, primarily as screws for stabilising fractured bones.

"This means patients do not need a second operation to remove the implant once the bone has healed, which is often necessary with more conventional materials," explains Olof Hildeberg.

The material has also attracted interest for stents used to keep blood vessels open after procedures such as the treatment of arterial narrowing.

"Unlike traditional stents, which are typically made from metals that remain permanently in the body, magnesium gradually corrodes in bodily fluids and is converted into substances that the body can process naturally," says Elsebeth Schröder, Professor of Quantum Device Physics, who supervised all three bachelor’s projects.

A key challenge in developing magnesium-based implants is getting the timing right. The material must degrade slowly enough to support the healing process, but not remain in the body longer than necessary. One well-known problem is that magnesium implants can degrade too quickly, before healing is complete. Improving such implants therefore requires a deeper understanding of how magnesium behaves in the human body.

How do you stop magnesium from degrading too quickly?

Together with students John Bolin and Amanda Goold, Alva Limbäck and Olof Hildeberg investigated what happens when magnesium begins to corrode inside the body. More specifically, they examined how the amino acids glycine, proline and hydroxyproline, all naturally present in collagen, might help form a protective layer on the surface of magnesium implants. Their results show that these amino acids can indeed contribute to creating a protective surface coating, particularly when the magnesium contains small amounts of other metals. The findings could help researchers develop implants that degrade at a slower and more controlled rate. 

In the article Toward an understanding of magnesium in a biological environment: A density functional theory study, published by AIP Publishing, students Miranda Naurin, Sally Aldhaim, Moltas Elliver, Ludwig Hagby and Didrik Nilsson approached the problem from a slightly different perspective. 

Their work focused on how biological molecules interact with the implant surface and how these interactions may influence the degradation process. In particular, they investigated how magnesium and magnesium hydroxide interact in a biological environment. Magnesium hydroxide is one of the first compounds to form on the implant surface as degradation begins, making it particularly important to understand its behaviour in contact with water and bodily fluids. The team explored how the naturally occurring amino acids glycine, proline and glutamine affect a layer of magnesium hydroxide on a magnesium surface.

"We found that magnesium hydroxide does not bind very strongly to the magnesium surface and can move relatively freely across it. We also observed that adding an amino acid affected the interaction to some extent, although the specific amino acid made very little difference. One of the most interesting findings was that the bond between different magnesium hydroxide layers is much stronger than the bond between the hydroxide and the magnesium surface itself. This suggests that magnesium hydroxide tends to detach in clusters rather than dissolving layer by layer," says Miranda Naurin, lead author of the paper.

The insights could contribute to the development of improved surface treatments and alloy compositions that enable more controlled degradation of temporary implants such as stents and bone screws. 

Earlier this summer, students Anthony Veit Berg, Ablai Forster, Tim Hansson, Alex J. Jernstedt and Emmy Salminen also saw their article, First-principle study of the influence of hydroxyapatite on magnesium surfaces, published in Physical Chemistry Chemical Physics.

Their study examined how hydroxyapatite, a mineral naturally found in bones and teeth, binds to the surface of magnesium-based implants. They studied both pure magnesium and magnesium containing small amounts of calcium or zinc.

"We found that both calcium and zinc generally strengthened the interaction between hydroxyapatite and magnesium, although the effect depended on where the surface was doped. We also observed structural changes in both the surface and the hydroxyapatite as they interacted. One particularly interesting result was that, in some cases, the calcium dopant moved from the magnesium surface into the hydroxyapatite layer, affecting both the structure and energy of the system," says Anthony Veit Berg.

All three groups used density functional theory (DFT) simulations in their studies. 

Inspiring future research careers

The students attribute the success of the publications to a combination of strong scientific results, effective teamwork and dedicated supervision.

"I think the main reason was the collaboration, both within the group and with our supervisor. Everyone worked extremely well together, and we were all highly motivated to move the project forward. We also had an ambitious supervisor who recognised the potential of both the project and the people involved," says Miranda Naurin.

Anthony agrees:

"I think our work became publishable because we produced results that advanced our understanding of how hydroxyapatite interacts with both pure and doped magnesium surfaces. Those findings are directly relevant to the development of biodegradable magnesium implants."

Although the bachelor’s projects were completed in 2024 and 2025, several of the students are now pursuing master's studies. Through student assistant positions, funded by Nano Area of Advance and Materials Science Area of Advance at Chalmers, the lead authors have been able to devote time to refining the manuscripts and guiding them through the publication process.
Many are planning careers in industry after graduation. At the same time, the experience of publishing scientific research appears to have sparked a growing interest in academia.

"You definitely become more interested in staying in academia once you've experienced it firsthand," says Miranda.

Many around the table nod in agreement.

"Yes, it certainly helps," says Olof.