Axe Santé: ALPICAT, a project to combat bacterial resistance.

The Axe Santé is an interdisciplinary center for the development of sustainable health technologies that brings together all the research institutes of the HES-SO Valais Wallis. We met Marc Mathieu, Professor at the Life Technologies Institute, to talk about a project supported by the Axe Santé on which he worked with two colleagues from the Enerypolis Campus for several months: ALPICAT, i.e., the development of prototype catheter ferrules whose surface is coated with antimicrobial molecules.

The challenge of sterilizing medical tools

It's not uncommon to hear in the press that certain bacteria are resistant to antibiotics. Bacteria are necessary for life, but they pose numerous resistance problems, particularly in medical and hospital environments. These pathogens can be transmitted to human beings via medical equipment, for example. It is therefore essential to ensure sterilization of surgical tools and medical equipment in all situations. This is easier to do in a laboratory equipped with an autoclave (a hermetically sealed container used for sterilization) but can prove complicated in a doctor's surgery in an Alpine valley without access to this type of machine, or more particularly when operating in the field. What's more, this method of sterilization is costly, time-, energy- and space-intensive, and poses durability problems when medical equipment is single-use. Finally, the pharmaceutical industry offers many antimicrobials in different formulations, or surface disinfectants that have their limits when it comes to resistant bacterial strains. Professors Marc Mathieu, Bruno Schnyder and Samuel Rey-Mermet therefore want to offer healthcare professionals portable and reusable technologies based on antibacterial peptides with unique properties.

Antibacterial peptides at the service of medicine

Peptides are sequences of amino acids, and this family of molecules belongs to a class of compounds known as polymers. These amino acid sequences exist in natural form but can also be synthesized in the laboratory. For many years, chemical research has been investigating the properties of these molecules, and we know that some peptides are antimicrobial, others antioxidant, and that they can also support the immune system. Their highly active molecules, with properties that enable them to sterilize surfaces with complex geometries, offer high added value thanks to their innovative properties, and are therefore designed to disinfect restricted surfaces. Thus, the ALPICAT project proposes to provide a technology for sterilizing surgical tools or components whose surfaces are first brought into contact with a solution of peptides with antibacterial properties. However, the challenge in this area of research is to make the peptides stable, as natural molecules are vulnerable and have a rather short survival time. We therefore need to develop the right combination of peptides to ensure their prolonged efficacy, as well as how to combine them and graft them to the chosen surface.

An inter-institute project to test hypotheses

This is how Marc Mathieu, head of the Synthetic Peptides and Peptide Mimetics platform, directed his research project, supported by the Health Axis, towards the sterilization of 3D-printed medical catheters using a bath of antibacterial peptides. It turns out that Samuel Rey-Mermet, a researcher in industrial systems, and Bruno Schnyder, a researcher in microbiology at the Life Technologies Institute, are also part of this multi-disciplinary team. Parts designed and printed by the industrial systems teams were treated with peptides developed by Marc Mathieu, and their antimicrobial properties tested by Bruno Schnyder's team. Experiments have shown that these compounds can be used to sterilize connectors, ferrules, and catheters, or to create complex, reusable ferrules that disinfect liquids without the need for specialized, costly laboratory equipment. Marc Mathieu points out that it is difficult to sterilize certain surgical tools because their shape is sometimes very complex or their porosity leaves niches for bacteria that are complicated to sterilize. Treatment with grafted antibacterial peptides could be an effective, accessible, and sustainable solution to this problem, as it enables complete antibacterial coating of porous and complex surfaces.

Marc Mathieu, chemistry at the service of human health

Professor Marc Mathieu has been working as a teacher and researcher at HES-SO Valais-Wallis for 12 years. For 30 years now, he has been interested in biomolecules and peptides, and has devoted his thesis and post-doctorate, as well as part of his career in industry and his research projects at HES-SO Valais-Wallis, to this subject. In particular, he has worked in the field of anti-cancer drugs with industrial partners, start-ups, and SMEs. He has always wanted to put his skills in the exciting field of bio-organic chemistry at the service of healthcare, because he is aware of the immense potential of these peptides, which could be used to treat numerous public health problems.

Photo: credits © HES-SO Valais-Wallis, Laurent Darbellay, from left to right: Prof. Dr. Marc Mathieu, Peptide Laboratory (TEVI), Prof. Dr. Samuel Rey-Mermet, Powder Laboratory (ISI), Prof. Dr. Bruno Schynder, Microbiology Laboratory (TEVI).