title: Bactericidal activity of partially oxidized nanodiamonds.
abstract: 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.
authors.affiliation: Advanced Ceramics, University of Bremen , Am Biologischen Garten 2, 28359 Bremen, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Wehling
authors.forename: Ralf
authors.initials: R
authors.lastname: Dringen
authors.forename: Richard N
authors.initials: RN
authors.lastname: Zare
authors.forename: Michael
authors.initials: M
authors.lastname: Maas
authors.forename: Kurosch
authors.initials: K
authors.lastname: Rezwan
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry*; D001412:Bacillus subtilis / Q000187:drug effects / Q000378:metabolism; D004337:Drug Carriers; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism; D006094:Gram-Positive Bacteria / Q000187:drug effects; D053768:Metal Nanoparticles / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D058612:Nanodiamonds / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D010100:Oxygen / Q000737:chemistry*; D010316:Particle Size; D011208:Powders / Q000737:chemistry; D011506:Proteins / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000737:chemistry; D012834:Silver / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000900:Anti-Bacterial Agents; D004337:Drug Carriers; D058612:Nanodiamonds; D011208:Powders; D011506:Proteins; D017382:Reactive Oxygen Species; D012834:Silver; D010100:Oxygen