It takes two for chronic wounds to heal: Dispersing bacterial biofilm and modulating inflammation with dual action plasma coatings

Thomas Danny Michl, Dung Thuy Thi Tran, Hannah Frederike Kuckling, Aigerim Zhalgasbaikyzy, Barbora Ivanovská, Laura Elena González García, Rahul Madathiparambil Visalakshan, Krasimir Vasilev

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)
2 Downloads (Pure)


Chronic wounds are affecting increasingly larger portions of the general population and their treatment has essentially remained unchanged for the past century. This lack of progress is due to the complex problem that chronic wounds are simultaneously infected and inflamed. Both aspects need to be addressed together to achieve a better healing outcome. Hence, we hereby demonstrate that the stable nitroxide radical (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) can be plasma polymerized into smooth coatings (TEMPOpp), as seen via atomic force microscopy, X-ray photoelectron spectroscopy and ellipsometry. Upon contact with water, these coatings leach nitroxides into aqueous supernatant, as measured via EPR. We then exploited the known cell-signalling qualities of TEMPO to change the cellular behaviour of bacteria and human cells that come into contact with the surfaces. Specifically, the TEMPOpp coatings not only suppressed biofilm formation of the opportunistic bacterium Staphylococcus epidermidis but also dispersed already formed biofilm in a dose-dependent manner; a crucial aspect in treating chronic wounds that contain bacterial biofilm. Thus the coatings' microbiological efficacy correlated with their thickness and the thickest coating was the most efficient. Furthermore, this dose-dependent effect was mirrored in significant cytokine reduction of activated THP-1 macrophages for the four cytokines TNF-α, IL-1β, IL-6 and IP-10. At the same time, the THP-1 cells retained their ability to adhere and colonize the surfaces, as verified via SEM imaging. Thus, summarily, we have exploited the unique qualities of plasma polymerized TEMPO coatings in targeting both infection and inflammation simultaneously; demonstrating a novel alternative to how chronic wounds could be treated in the future.

Original languageEnglish
Pages (from-to)7368-7376
Number of pages9
JournalRSC Advances
Issue number13
Publication statusPublished - 18 Feb 2020
Externally publishedYes


  • bacterial biofilms
  • dual action plasma coatings
  • chronic wounds
  • Atomic force microscopy
  • nitroxides
  • EPR


Dive into the research topics of 'It takes two for chronic wounds to heal: Dispersing bacterial biofilm and modulating inflammation with dual action plasma coatings'. Together they form a unique fingerprint.

Cite this