title: Co-precipitation of tobramycin into biomimetically coated orthopedic fixation pins employing submicron-thin seed layers of hydroxyapatite.
abstract: The migration, loosening and cut-out of implants and nosocomial infections are current problems associated with implant surgery. New innovative strategies to overcome these issues are emphasized in today's research. The current work presents a novel strategy involving co-precipitation of tobramycin with biomimetic hydroxyapatite (HA) formation to produce implant coatings that control local drug delivery to prevent early bacterial colonization of the implant. A submicron- thin HA layer served as seed layer for the co-precipitation process and allowed for incorporation of tobramycin in the coating from a stock solution of antibiotic concentrations as high as 20 mg/ml. Concentrations from 0.5 to 20 mg/ml tobramycin and process temperatures of 37 °C and 60 °C were tested to assess the optimal parameters for a thin tobramycin- delivering HA coating on discs and orthopedic fixation pins. The morphology and thickness of the coating and the drug-release profile were evaluated via scanning electron microscopy and high performance liquid chromatography. The coatings delivered pharmaceutically relevant amounts of tobramycin over a period of 12 days. To the best of our knowledge, this is the longest release period ever observed for a fast-loaded biomimetic implant coating. The presented approach could form the foundation for development of combination device/antibiotic delivery vehicles tailored to meet well-defined clinical needs while combating infections and ensuring fast implant in-growth.
authors.forename: Jan H
authors.initials: JH
authors.lastname: Sörensen
authors.forename: Mirjam
authors.initials: M
authors.lastname: Lilja
authors.forename: Maria
authors.initials: M
authors.lastname: Åstrand
authors.forename: Torben C
authors.initials: TC
authors.lastname: Sörensen
authors.forename: Philip
authors.initials: P
authors.lastname: Procter
authors.forename: Maria
authors.initials: M
authors.lastname: Strømme
authors.affiliation: Division for Nanotechnology and Functional Materials, The Angstrom Laboratory, Uppsala University, Box 534, 751 21 Uppsala, Sweden. maria.stromme@angstrom.uu.se.
authors.forename: Hartwig
authors.initials: H
authors.lastname: Steckel
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000032:analysis / Q000737:chemistry* / Q000627:therapeutic use; D001424:Bacterial Infections / Q000517:prevention & control; D040761:Biomimetic Materials / Q000737:chemistry* / Q000378:metabolism; D001858:Bone Nails; D011232:Chemical Precipitation; D003428:Cross Infection / Q000517:prevention & control; D003692:Delayed-Action Preparations / Q000008:administration & dosage / Q000737:chemistry / Q000627:therapeutic use; D016503:Drug Delivery Systems; D017886:Durapatite / Q000737:chemistry* / Q000378:metabolism; D006358:Hot Temperature; D006801:Humans; D016268:Internal Fixators; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D009994:Osmolar Concentration; D012995:Solubility; D013499:Surface Properties; D013530:Surgical Wound Infection / Q000517:prevention & control; D014025:Titanium / Q000737:chemistry; D014031:Tobramycin / Q000008:administration & dosage / Q000032:analysis / Q000737:chemistry* / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D003692:Delayed-Action Preparations; C009495:titanium dioxide; D017886:Durapatite; D014025:Titanium; D014031:Tobramycin