title: Hydroxyapatite composites designed for antibiotic drug delivery and bone reconstruction: a caprine model.
abstract: The purpose of this study was to investigate the feasibility of fabricating a drug delivery system that serves a dual function, to eradicate infection as well as to provide a scaffold for osseous integration. Two porous composite systems were fabricated using hydroxyapatite (HA) as the carrier for gentamicin sulfate (GS), an aminoglycoside antibiotic. Structural and mechanical properties of porous HA-GS composites were characterized and the in vitro release behavior of GS from fabricated composites was monitored and compared with the well-known polymethylmethacrylate (PMMA)-GS delivery system. Scanning electron microscopy revealed a macropore range of 150 to 200 microm and 100 to 190 microm for the sintered and unsintered HA-GS composites, respectively. The effect of GS inclusion on bone apposition and ingrowth was assessed using a caprine model. Plugs 10 mm x 6 mm of cylindrical tricalcium phosphate, sintered HA, and sintered HA-GS were implanted in the femoral diaphysis for a period of 6 weeks. Data collected during the in vitro study showed that GS can successfully be incorporated into HA and used as a drug delivery system to eradicate Staphylococcus aureus. In vivo data confirmed that the inclusion of GS within a ceramic matrix did not stimulate or inhibit osteointegration or bone apposition. In conclusion, the fabricated sintered HA-GS composite may be beneficial in the treatment of infected osseous sites as a drug delivery system.
authors.affiliation: Department of Bioengineering, Clemson University, South Carolina 29634-0905, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Rogers-Foy
authors.forename: D L
authors.initials: DL
authors.lastname: Powers
authors.forename: D A
authors.initials: DA
authors.lastname: Brosnan
authors.forename: S F
authors.initials: SF
authors.lastname: Barefoot
authors.forename: R J
authors.initials: RJ
authors.lastname: Friedman
authors.forename: M
authors.initials: M
authors.lastname: LaBerge
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics*; D001672:Biocompatible Materials / Q000494:pharmacology*; D002130:Calcium Phosphates / Q000494:pharmacology; D004195:Disease Models, Animal; D016503:Drug Delivery Systems; D017886:Durapatite / Q000494:pharmacology*; D005269:Femur / Q000502:physiology / Q000601:surgery / Q000648:ultrastructure; D050723:Fractures, Bone / Q000601:surgery*; D005839:Gentamicins / Q000493:pharmacokinetics*; D006041:Goats; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D016348:Osseointegration / Q000187:drug effects; D014945:Wound Healing / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D001672:Biocompatible Materials; D002130:Calcium Phosphates; D005839:Gentamicins; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; C485838:calcium phosphate, monobasic, anhydrous; D017886:Durapatite; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous