Bacteria in wounds often grow within biofilms, which are structured communities of bacteria encased by polymeric matrices. In these films, bacteria are highly tolerant to antimicrobial agents. Ga3+ has been shown to provide an effective treatment: Ga3+, which is chemically similar to Fe3+, blocks Fe3+ binding sites on redox proteins. These proteins are indispensable for bacterial growth and also for the biofilm formation.
However, Ga3+ has two drawbacks: a concentration above 36 μM is highly toxic for mammalian cells and Ga3+ forms insoluble precipitates (Ga(OH)3) under physiological conditions, reducing its bioavailability.
Nicholas L. Abbott, University of Wisconsin, Madison, USA, and colleagues designed a microfilm comprising a polyelectrolyte layer of poly(allylaminehydrochloride) and poly(acrylic acid) containing Ga(NO3)3 and a mechanically robust poly(vinylalcohol) film. This film is then used to functionalize the surface of wound dressings. The polymeric film steadily releases Ga3+ in noncytotoxic concentrations over 20 days and effectively disperses existing biofilms, as well as prevents the formation of new bacterial biofilms.
- Gallium-Loaded Dissolvable Microfilm Constructs that Provide Sustained Release of Ga3+ for Management of Biofilms,
Maggie Herron, Michael J. Schurr, Christopher J. Murphy, Jonathan F. McAnulty, Charles J. Czuprynski, Nicholas L. Abbott,
Adv. Healthcare Mater. 2015.