Bactericidal Activity of Partially Oxidized Nanodiamonds

• Published in: ACS nano Vol. 8; no. 6; pp. 6475 - 6483
• Main Authors: Wehling, Julia, Dringen, Ralf, Zare, Richard N, Maas, Michael, Rezwan, Kurosch
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 24.06.2014
• Subjects: Anhydrides; Anti-Bacterial Agents - chemistry; Antiinfectives and antibacterials; Bacillus subtilis - drug effects; Bacillus subtilis - metabolism; Bacteria; Biocompatibility; Dispersions; Drug Carriers; Escherichia coli; Escherichia coli - drug effects; Escherichia coli - metabolism; Gram-Positive Bacteria - drug effects; Metal Nanoparticles - chemistry; Microscopy, Electron, Transmission; Nanodiamonds - chemistry; Nanostructure; Nanotechnology - methods; Oxygen - chemistry; Particle Size; Powders - chemistry; Proteins - chemistry; Reactive Oxygen Species - chemistry; Silver - chemistry; Spectroscopy, Fourier Transform Infrared; Surface chemistry; Surgical implants; B. subtilis; nanodiamond; antibacterial; anhydride; E. coli
• ISSN: 1936-0851; 1936-086X
• DOI: 10.1021/nn502230m

Nanodiamonds are a class of carbon-based nanoparticles that are rapidly gaining attention, particularly for biomedical applications, i.e., as drug carriers, for bioimaging, or as implant coatings. Nanodiamonds have generally been considered biocompatible with a broad variety of eukaryotic cells. We show that, depending on their surface composition, nanodiamonds kill Gram-positive and -negative bacteria rapidly and efficiently. We investigated six different types of nanodiamonds exhibiting diverse oxygen-containing surface groups that were created using standard pretreatment methods for forming nanodiamond dispersions. Our experiments suggest that the antibacterial activity of nanodiamond is linked to the presence of partially oxidized and negatively charged surfaces, specifically those containing acid anhydride groups. Furthermore, proteins were found to control the bactericidal properties of nanodiamonds by covering these surface groups, which explains the previously reported biocompatibility of nanodiamonds. Our findings describe the discovery of an exciting property of partially oxidized nanodiamonds as a potent antibacterial agent.