Antimicrobial activity of menthol modified nanodiamond particles

Advances in nanotechnology have seen the development of several microbiocidal nanoparticles displaying activity against biofilms. These applications benefit from one or more combinations of the nanoparticles properties. Nanoparticles may indeed concentrate drugs on their surface resulting in polyvalent effects and improved efficacy to fight against bacteria. Nanodiamonds (NDs) are among the most promising new materials for biomedical applications. We elucidate in this paper the effect of menthol modified nanodiamond particles (ND-menthol) on bacterial viability against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. We show that while ND-menthol particles are non-toxic to both pathogens, they show significant antibiofilm activity. The presence of ND-menthol particles reduce biofilm formation more efficiently than free menthol, unmodified oxidized NDs and ampicillin, a commonly used antibiotic. Our findings might be thus a step forward towards the development of alternative non antibiotic based strategies targeting bacterial infections.