Bioactive doped metals: high synergism in the bactericidal activity of chlorhexidine@silver towards wound pathogenic bacteria

Abstract

The entrapment of chlorhexidine (CH) within metallic silver (CH@Ag) results in a composite material bearing powerful synergetic bactericidal action towards two opportunistic wound pathogenic bacteria, the Gram-negative Pseudomonas aeruginosa and the Gram-positive Staphylococcus epidermidis. TEM and STEM imaging revealed morphological abnormalities in bacteria exposed to the composite. Release profiles of the active ingredients, CH and ionic silver, from the composite were evaluated by UV spectroscopy and by ICP-MS elemental analysis, and indicated that the strong bactericidal effects were associated with their co-release and presence in the solution. The use of both powder form and pressed form of CH@Ag provides means to control the release kinetics of entrapped CH from the composite and demonstrates the potential application of such composites in wound treatments.