New hydrogel that works against resistant bacteria as well

The beneficial properties of antimicrobial peptides have been known for some decades, and thousands of different varieties occurring in the natural immune systems of humans, animals and plants have been discovered.

After testing our new hydrogel on different types of bacteria, we observed a high level of effectiveness, including against those which have become resistant to antibiotics," says Martin Andersson, research leader for the study and Professor at the Department of Chemistry and Chemical Engineering at Chalmers University of Technology.

The scientific article Antimicrobial Peptide-Functionalized Mesoporous Hydrogels has been published in ACS Biomaterials Science & Engineering.

The main purpose of the studies so far has been to explore new medical technology solutions to help reduce the use of systemic antibiotics. Resistant bacteria cause what is referred to as hospital-acquired infection - a life-threatening condition and is increasing in incidence worldwide.

Mimicking the natural immune system

The active substance in the new bactericidal material consists of antimicrobial peptides, small proteins which are found naturally in our immune system.

"With these types of peptides, there is a very low risk for bacteria to develop resistance against them, since they only affect the outermost membrane of the bacteria. That is perhaps the foremost reason why they are so interesting to work with," says Martin Andersson.

Researchers have long tried to find ways to use these peptides in medical devices, but so far without much success. The problem is that they break down quickly when they come into contact with bodily fluids such as blood. The current study describes how the researchers managed to overcome the problem through the development of a nanostructured hydrogel, into which the peptides are permanently bound, creating a protective environment.

"The material is very promising. It is harmless to the body's own cells and gentle on the skin. In our measurements, the protective effect of the hydrogel on the antimicrobial peptides is clear - the peptides degrade much slower when they are bound to it," says Edvin Blomstrand, doctoral student at the Department of Chemistry and Chemical Engineering at Chalmers, and one of the main authors of the article.

"We expected good results, but we were really positively surprised at quite how effective the material has proven," adds Martin Andersson.

According to the researchers, this new material is the first medical device to make successful use of antimicrobial peptides in a clinically and commercially viable manner. There are many varied and promising opportunities for clinical application.