Light-activated wound dressing fights antibiotic-resistant bacteria
Some wounds just won’t heal. They keep getting infected because bacteria colonize them. This is particularly problematic after surgery. However, antibiotics are becoming less effective in an increasing number of cases, as many germs have now developed resistance. Researchers at the Leibniz Institute for Surface Modification (IOM) in Leipzig have now developed a novel wound dressing that fights bacteria using light.
A wound dressing that acts like skin
The team developed a transparent hydrogel – a water-based, gel-like material. It consists of a medically well-tolerated plastic and gelatin and has properties similar to those of human skin. At the same time, the material can store moisture and release active ingredients in a controlled manner. The researchers integrated tiny silver particles – so-called silver nanoparticles – into the hydrogel. In addition, the wound dressing contains special dyes.
This technique is known as photodynamic therapy. When light strikes the dyes, oxygen compounds are formed that can specifically target and destroy bacteria. The team tested the wound dressing on the bacteria Escherichia coli and Staphylococcus aureus. Both species frequently cause wound infections.
Stronger Together Than Alone
On their own, the silver particles had little effect against the bacteria. Only when combined with the dyes did the effect increase significantly. The combination of silver nanoparticles and the dye eosin Y was particularly successful. The dye alone was already effective against the bacteria. However, when combined with the silver nanoparticles, it was significantly more effective. For the tested bacterial species, the antibacterial effect increased by 97 and 98 percent, respectively.
The researchers attribute this effect to the fact that Eosin Y distributes particularly well within the material and interacts effectively with the silver nanoparticles and the damaged bacterial membranes.
The study from Leipzig shows that light-activated wound dressings containing silver nanoparticles could serve as an alternative or supplement to antibiotics in the future. This approach opens up new possibilities for the treatment of chronic wounds, particularly in cases of infections caused by resistant pathogens. However, further testing is needed before such wound dressings can be used in clinical practice.
Original publication:
T. Şener Raman, M. Kühnert, R. Konieczny, N. Lippmann, A. Kaiser, R. Werdehausen, B. Abel, A. Schulze
Synergistic effects of ionic photosensitizers and silver nanoparticles in PEGDA/gelatin hybrid hydrogels for advanced antibacterial photodynamic therapy, Biomaterials Advances 187 (2026) 214946
