title: Sustainable antimicrobial effect of silver sulfadiazine-loaded nanosheets on infection in a mouse model of partial-thickness burn injury.
abstract: Partial-thickness burn injury has the potential for reepithelialization and heals within 3weeks. If the wound is infected by bacteria before reepithelization, however, the depth of disruption increases and the lesion easily progresses to the full-thickness dermal layers. In the treatment of partial-thickness burn injury, it is important to prevent the wound area from bacterial infection with an antimicrobial dressing. Here, we have tested the antimicrobial properties of polymeric ultra-thin films composed of poly(lactic acid) (termed "PLA nanosheets"), which have high flexibility, adhesive strength and transparency, and silver sulfadiazine (AgSD), which exhibits antimicrobial efficacy. The AgSD-loaded nanosheet released Ag(+) for more than 3days, and exerted antimicrobial efficacy against methicillin-resistant Staphylococcus aureus (MRSA) in an in vitro Kirby-Bauer test. By contrast, a cell viability assay indicated that the dose of AgSD used in the PLA nanosheets did not show significant cytotoxicity toward fibroblasts. In vivo evaluation using a mouse model of infection in a partial-thickness burn wound demonstrated that the nanosheet significantly reduced the number of MRSA bacteria on the lesion (more than 10(5)-fold) and suppressed the inflammatory reaction, thereby preventing a protracted wound healing process.
authors.affiliation: Department of Life Science and Medical Bio-Science, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Ito
authors.affiliation: Department of Life Science and Medical Bio-Science, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Saito
authors.affiliation: Department of Life Science and Medical Bio-Science, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan.
authors.forename: Toshinori
authors.initials: T
authors.lastname: Fujie
authors.affiliation: Department of Life Science and Medical Bio-Science, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Nishiwaki
authors.affiliation: Division of Traumatology, Research Institute, National Defense Medical College, Saitama, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Miyazaki
authors.affiliation: Department of Immunology and Microbiology, National Defense Medical College, Saitama, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Kinoshita
authors.affiliation: Department of Immunology and Microbiology, National Defense Medical College, Saitama, Japan.
authors.forename: Daizoh
authors.initials: D
authors.lastname: Saitoh
authors.affiliation: Project Research Institutes, Comprehensive Research Organization, Waseda University, Tokyo, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Ohtsubo
authors.affiliation: Department of Life Science and Medical Bio-Science, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan. Electronic address: takeoka@waseda.jp.
authors.forename: Shinji
authors.initials: S
authors.lastname: Takeoka
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology; D002056:Burns / Q000188:drug therapy / Q000382:microbiology; D055624:Methicillin-Resistant Staphylococcus aureus; D051379:Mice; D053758:Nanoparticles / Q000737:chemistry*; D012837:Silver Sulfadiazine / Q000737:chemistry / Q000494:pharmacology; D013203:Staphylococcal Infections / Q000188:drug therapy*; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D000890:Anti-Infective Agents; D012837:Silver Sulfadiazine
keywords: Antimicrobial; Poly(lactic acid); Polymer nanosheet; Silver sulfadiazine; Wound dressing