title: Silver oxide-containing hydroxyapatite coating has in vivo antibacterial activity in the rat tibia.
abstract: Bacterial infection is a serious postoperative complication of joint replacement. To prevent infections related to implantation, we have developed a novel antibacterial coating with Ag-containing hydroxyapatite (Ag-HA). In the present study, we examined the antibacterial activity of Ag-HA implant coatings in the medullary cavity of rat tibiae. Forty 10-week-old rats received implantation of Ag-HA- or HA-coated titanium rods, then were inoculated with ∼1.0 × 10(2) colony-forming units of methicillin-resistant Staphylococcus aureus. Bacterial counts were calculated for rats euthanized at 24, 48, and 72 h postoperatively. Serum levels of Ag (in the Ag-HA group only) were calculated for rats euthanized at 24, 48, 72 h and 4 weeks. Radiographic evaluations of bone infection were also performed at 4 weeks. Tibiae from both groups showing infection were evaluated histologically. Significant differences in bacterial counts were seen at 24, 48, and 72 h. Mean concentrations of Ag in serum peaked about 48 h after implantation, then gradually decreased. Mean radiographic scores for infection were significantly lower with Ag-HA implants than with HA implants. Histological examination showed better results for abscesses, bone resorption, and destruction of cortical bone around Ag-HA-coated implants. These results indicate that Ag-HA coatings may help prevent surgical-site infections associated with joint replacement.
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501, Japan. 10624002@edu.cc.saga-u.ac.jp
authors.forename: Takayuki
authors.initials: T
authors.lastname: Akiyama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miyamoto
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Yonekura
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Tsukamoto
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Ando
authors.forename: Iwao
authors.initials: I
authors.lastname: Noda
authors.forename: Motoki
authors.initials: M
authors.lastname: Sonohata
authors.forename: Masaaki
authors.initials: M
authors.lastname: Mawatari
mesh_terms: D000038:Abscess / Q000188:drug therapy / Q000473:pathology; D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D001858:Bone Nails; D020099:Coated Materials, Biocompatible / Q000494:pharmacology*; D004195:Disease Models, Animal; D006882:Hydroxyapatites / Q000494:pharmacology*; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D010019:Osteomyelitis / Q000188:drug therapy / Q000473:pathology; D010087:Oxides / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018030:Silver Compounds / Q000494:pharmacology*; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000473:pathology; D013530:Surgical Wound Infection / Q000473:pathology / Q000517:prevention & control; D013977:Tibia / Q000601:surgery* / Q000648:ultrastructure; D014025:Titanium
chemical_list: D000890:Anti-Infective Agents; D020099:Coated Materials, Biocompatible; D006882:Hydroxyapatites; D010087:Oxides; D018030:Silver Compounds; C475044:hydroxyapatite cement; C040225:disilver oxide; D014025:Titanium