title: New life for an old antibiotic.
abstract: Restoring the antibacterial properties of existing antibiotics is of great concern. Herein, we present, for the first time, the formation and deposition of stable antibiotic nanoparticles (NPs) on graphene oxide (GO) sheets by a facile one-step sonochemical technique. Sonochemically synthesized graphene oxide/tetracycline (GO/TET) composite shows enhanced activity against both sensitive and resistant Staphylococcus aureus (S. aureus). The size and deposition of tetracycline (TET) nanoparticles on GO can be controlled by varying the sonication time. The synthesized NPs ranged from 21 to 180 nm. Moreover, ultrasonic irradiation does not cause any structural and chemical changes to the TET molecule as confirmed by Fourier transform infrared spectroscopy (FTIR). The virtue of π-π stacking between GO and TET additionally facilitate the coating of TET NPs upon GO. A time dependent release kinetics of TET NPs from the GO surface is also monitored providing important insights regarding the mechanism of antibacterial activity of GO/TET composites. Our results show that the GO/TET composite is bactericidal in nature, resulting in similar values of minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). This composite is found to be active against TET resistant S. aureus at a concentration four times lower than the pristine TET. The sensitive S. aureus follows the same trend showing six times lower MIC values compared to pristine TET. GO shows no activity against both sensitive and resistant S. aureus even at a concentration as high as 1 mg/mL but influences the biocidal activity of the GO/TET composite. We propose that the unique structure and composition manifested by GO/TET composites may be further utilized for different formulations of antibiotics with GO. The sonochemical method used in this work can be precisely tailored for the stable deposition of a variety of antibiotics on the GO surface to reduce health risks and increase the spectrum of applications.
authors.affiliation: †Department of Chemistry, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel.
authors.forename: Rahul Kumar
authors.initials: RK
authors.lastname: Mishra
authors.affiliation: †Department of Chemistry, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel.
authors.forename: Elad
authors.initials: E
authors.lastname: Segal
authors.affiliation: †Department of Chemistry, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel.
authors.forename: Anat
authors.initials: A
authors.lastname: Lipovsky
authors.affiliation: ∥The Mina and Everard Goodman Faculty of Life Sciences, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel.
authors.forename: Michal
authors.initials: M
authors.lastname: Natan
authors.affiliation: ∥The Mina and Everard Goodman Faculty of Life Sciences, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel.
authors.forename: Ehud
authors.initials: E
authors.lastname: Banin
authors.affiliation: †Department of Chemistry, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel.|§Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan.
authors.forename: Aharon
authors.initials: A
authors.lastname: Gedanken
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000737:chemistry; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D004058:Diffusion; D004355:Drug Stability; D004357:Drug Synergism; D006108:Graphite / Q000737:chemistry*; D008422:Materials Testing; D053769:Nanocapsules / Q000737:chemistry* / Q000648:ultrastructure*; D010087:Oxides / Q000737:chemistry; D013010:Sonication / Q000379:methods; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000502:physiology; D013752:Tetracycline / Q000008:administration & dosage* / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D053769:Nanocapsules; D010087:Oxides; D006108:Graphite; D013752:Tetracycline
keywords: S. aureus; antibacterial; bactericidal; graphene oxide; sonochemistry; tetracycline nanoparticles