title: Synergistic antibacterial effects of localized heat and oxidative stress caused by hydroxyl radicals mediated by graphene/iron oxide-based nanocomposites.
abstract: This work develops a composite system of reduced graphene oxide (rGO)-iron oxide nanoparticles (rGO-IONP) that can synergistically induce physical and chemical damage to methicillin-resistant Staphylococcus aureus (MRSA) that are present in subcutaneous abscesses. rGO-IONP was synthesized by the chemical deposition of Fe(2+)/Fe(3+) ions on nanosheets of rGO in aqueous ammonia. The antibacterial efficacy of the as-prepared rGO-IONP was evaluated in a mouse model with MRSA-infected subcutaneous abscesses. Upon exposure to a near-infrared laser in vitro, rGO-IONP synergistically generated localized heat and large amounts of hydroxyl radicals, which inactivated MRSA. The in vivo results reveal that combined treatment with localized heat and oxidative stress that is caused by hydroxyl radicals accelerated the healing of wounds associated with MRSA-infected abscesses. The above results demonstrate that an rGO-IONP nanocomposite system that can effectively inactivate multiple-drug-resistant bacteria in subcutaneous infections was successfully developed.
  
  
  BACKGROUND
  The emergence of methicillin-resistant S. aureus (MRSA) has posed a significant problem in the clinical setting. Thus, it is imperative to develop new treatment strategies against this. In this study, the authors described the use of reduced graphene oxide (rGO)-iron oxide nanoparticles (rGO-IONP) to induce heat and chemical damage to MRSA. This approach may provide a platform the design of other treatment modalities against multiple-drug-resistant bacteria.
authors.affiliation: Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan (ROC).
authors.forename: Wen-Yu
authors.initials: WY
authors.lastname: Pan
authors.affiliation: Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan (ROC).
authors.forename: Chieh-Cheng
authors.initials: CC
authors.lastname: Huang
authors.affiliation: Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan (ROC).
authors.forename: Tzu-Tsen
authors.initials: TT
authors.lastname: Lin
authors.affiliation: Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan (ROC).
authors.forename: Hsin-Yi
authors.initials: HY
authors.lastname: Hu
authors.affiliation: Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan (ROC).
authors.forename: Wei-Chih
authors.initials: WC
authors.lastname: Lin
authors.affiliation: Department of Pediatrics, National Taiwan University Hospital Hsinchu Branch, Hsinchu, Taiwan (ROC). Electronic address: deary0308@gmail.com.
authors.forename: Meng-Ju
authors.initials: MJ
authors.lastname: Li
authors.affiliation: Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan (ROC); Institute of Biomedical Engineering, National Tsing Hua University, Hsinchu, Taiwan (ROC). Electronic address: hwsung@mx.nthu.edu.tw.
authors.forename: Hsing-Wen
authors.initials: HW
authors.lastname: Sung
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000627:therapeutic use*; D005260:Female; D005290:Ferric Compounds / Q000737:chemistry / Q000627:therapeutic use*; D006108:Graphite / Q000737:chemistry / Q000627:therapeutic use*; D006358:Hot Temperature; D017665:Hydroxyl Radical / Q000378:metabolism*; D006979:Hyperthermia, Induced / Q000379:methods; D007259:Infrared Rays; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects*; D008807:Mice, Inbred BALB C; D053761:Nanocomposites / Q000737:chemistry / Q000627:therapeutic use* / Q000648:ultrastructure; D018384:Oxidative Stress / Q000187:drug effects; D010789:Phototherapy / Q000379:methods; D013203:Staphylococcal Infections / Q000378:metabolism / Q000628:therapy*
chemical_list: D000900:Anti-Bacterial Agents; D005290:Ferric Compounds; C000499:ferric oxide; D017665:Hydroxyl Radical; D006108:Graphite
keywords: Fenton reaction; Hyperthermia; Multiple-drug-resistant bacteria; Oxidative stress; Photothermal therapy