Researchers claim to have developed cellulose membranes that eliminate wound infections early on, as they look to tackle the issues of increased antibiotic resistance.
If germs invade a wound, they can trigger a long-lasting infection that may fail to heal or even spread throughout the body, leading to life-threatening blood poisoning (sepsis). However, the problem of antibiotic resistance is becoming more and more widespread, particularly in complex wounds, as bacteria such as staphylococci have become resistant to this treatment.
The Empa (Swiss Federal Laboratories for Materials Science and Technology) researchers, led by researcher Katharina Maniura from the Biointerfaces lab (St. Gallen, Switzerland) produced fine membranes from cellulose using electrospinning technology. The cellulose fibres, with a diameter of less than one micrometre, were spun into a delicate multilayered, three-dimensional fabric. The membranes became particularly flexible and at the same time stable after the researchers had added the polymer polyurethane to the spinning process.
In order to achieve an antibacterial effect, the researchers designed multifunctional peptides —which can bind to cellulose fibres and exhibit antimicrobial activity. Peptides have several advantages compared to larger proteins. For example, they are easier to produce and more stable than proteins, which react more sensitively to the chemical conditions in a wound.
If the cellulose membranes are treated with such a peptide solution, the fibre scaffold will become saturated with peptides. In cell culture experiments, the researchers then showed that the peptide-containing membranes are well tolerated by human skin cells. However, the cellulose membranes were a death sentence for bacteria such as staphylococci, which are often found in poorly healing wounds.
Maniura says: “In bacterial cultures, over 99.99% of the germs were killed by the peptide-containing membranes.”
In future, the antimicrobial membranes will be equipped with additional functions. “The peptides might, for instance, be functionalised with binding sites that enable the controlled release of further therapeutic substances,” adds Maniura.