title: In vivo antibacterial and silver-releasing properties of novel thermal sprayed silver-containing hydroxyapatite coating.
abstract: One of the serious postoperative complications associated with joint replacement is bacterial infection. In addressing this problem, we have previously described the development of a novel thermal spraying technology combining silver (Ag) showing antibacterial activity with hydroxyapatite (HA) displaying good biocompatibility and osteoconductivity, and reported the in vitro properties. This study evaluated serum Ag ion concentrations and antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) using a subcutaneous rat model. HA loaded with 3 wt % of silver oxide (Ag-HA) and plain HA were sprayed on the surface of titanium disks. Ag-HA- or HA-coated samples were implanted into the back subcutaneous pockets of male Sprague-Dawley rats. Mean serum Ag ion concentration in the Ag-HA group increased to more than 50 ppb by 48 h after implantation, then decreased gradually to baseline levels. Mean (+/- standard error of the mean) number of viable MRSA on HA coating was (1.5 +/- 0.5) x 10(5), which is significantly more than the (1.1 +/- 0.4) x 10(4) on Ag-HA coating (p < 0.001). Ag-HA coating offers good abilities to release Ag ions and kill MRSA in vivo.
authors.affiliation: Department of Orthopedic Surgery, Faculty of Medicine, Saga University, Saga 849-8501, Japan. shimazak@cc.saga-u.ac.jp
authors.forename: Takafumi
authors.initials: T
authors.lastname: Shimazaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miyamoto
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Ando
authors.forename: Iwao
authors.initials: I
authors.lastname: Noda
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Yonekura
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Kawano
authors.forename: Masaki
authors.initials: M
authors.lastname: Miyazaki
authors.forename: Masaaki
authors.initials: M
authors.lastname: Mawatari
authors.forename: Takao
authors.initials: T
authors.lastname: Hotokebuchi
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D015169:Colony Count, Microbial; D017886:Durapatite / Q000737:chemistry*; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D016459:Prosthesis-Related Infections / Q000517:prevention & control; D051381:Rats; D017207:Rats, Sprague-Dawley; D012834:Silver / Q000097:blood / Q000737:chemistry / Q000494:pharmacology*; D013242:Sterilization; D014025:Titanium
chemical_list: D000900:Anti-Bacterial Agents; D020099:Coated Materials, Biocompatible; D012834:Silver; D017886:Durapatite; D014025:Titanium