Nanoparticles coated with graphene flakes and antibiotics. This antibacterial nano-weapon is the goal of a new Nordic research project co-ordinated by Professor Ivan Mijakovic at Chalmers. The project aims to deliver the next generation of treatments against antibiotic-resistant bacteria.
Bacterial infections that cannot be treated due to antibiotic resistance is a rising and acute global problem. More than 700,000 people worldwide die each year due to infections caused by antibiotic-resistant bacteria.
In a worst-case scenario presented in a UN report in 2018, we can, if no measures are taken, reach a situation by 2050 where the death toll due to these infections rises to 10 million per year. As it is a time-consuming process to develop new antibiotics, and today's antibiotics are rapidly becoming ineffective, innovations are needed quickly.
Treatment of antibiotic resistant Staphylococcus aureus
"This is the right time for scientists to mobilise and try to solve this problem, which will be a real threat to mankind in a decade or two. Traditionally we all tend to think that the solution is to find new antibiotics, but we could also try to find a disruptive new technology that is not based on antibiotic discovery," says Ivan Mijakovic, Professor of Systems and Synthetic Biology at the Department of Biology and Biological Engineering at Chalmers, who is the co-ordinator of the new Nordic project.
The research project will run for three years, and in January 2021 it was awarded 15 MSEK by Nordforsk. The researchers will specifically be focusing on treatment of methicillin-resistant Staphylococcus aureus (MRSA), which, among other things, causes chronic skin infections and sepsis.
MRSA can also infect tissues and organs inside the body, such as heart and lungs, and they can also grow on different kinds of implants used in health care. MRSA-infections are easily spread in hospitals and cause great suffering in affected patients.
Combine three techniques in a new way
The idea of the project is to combine three already established techniques in a completely new way to create a new system for drug delivery.
Metal nanoparticles, graphene flakes and antibiotics all have antibacterial properties. Combined they would be even more powerful, as these particles most likely can penetrate the bacterial biofilm formed at the area of infection and release the antibiotic there.
Biofilm is the thick layer of bacteria and the mucus they produce when they attach to a surface and start to multiply, and it creates a protective barrier for the bacteria.
Graphene flakes cut and kill bacteria
Chalmers is one of the world leading universities in the research field of graphene. The idea of using graphene for medical treatments is relatively young but has great potential. August Yurgens is Professor at the Department of Microtechnology and Nanoscience at Chalmers. His research group is developing the process where the nanoparticles are coated axially with graphene flakes.
"Sharp edges of graphene flakes placed vertically on a surface cut through the membrane of cells of a certain size, which research from Ivan and other scientists at Chalmers already has shown. Small bacterial cells are killed when they are cut by the sharp graphene edges, but human cells, which are bigger, are not harmed. The graphene flakes will be coated with the drug for transporting it deeper into the infected tissue. The antibiotics will then be released in the infected tissue gradually, "says August Yurgens and continues:
"Since some chemicals used as drugs are non-soluble in water, the main constituent of our bodies, we must find other ways of transporting the drugs within the body. The graphene coated nanoparticles could be a solution to this problem."
His research group has made trials where they tried to grow graphene on silicon nanoparticles − with promising results.
"Of course, we are facing some challenges since the nanoparticles are spherical and for most efficient result, they need to be covered evenly with graphene flakes. We have several ideas on how we can solve that," he says.
Green nanoparticles and novel drugs
The other Nordic partners are DTU in Denmark, and the research institute SINTEF in Norway. DTU will deliver the so-called green nanoparticles, which produced from plant or bacterial extracts, for an environmentally friendly production.
Researchers at SINTEF are developing new drugs with antibacterial properties, which will be loaded on the graphene coated nanoparticles.
"Mechanism that effectively can be used against MRSA"
Ivan Mijakovic's research group will test the new nano-weapons for killing of bacterial biofilms. Ivan Mijakovic says that even if their study is successful, further obstacles must be overcome before this system can be used in patients.
Graphene-based nanotechnology is not yet allowed in medical treatments within the EU. But, since this area has such potential, there are ongoing clinical trials to ensure safe treatments.
"It usually takes decades to develop treatments like this. But we are at the forefront of developing a mechanism that we think can be effectively used against MRSA and other dangerous pathogens, and it is important that we test it and act now," says Ivan Mijakovic.
Text: Susanne Nilsson Lindh
