title: Characterization of daptomycin-loaded antibiotic cement.
abstract: Antibiotics are commonly mixed with polymethylmethacrylate (PMMA) cement to suppress severe periprosthetic infections associated with total joint arthroplasty. The relationship between antibiotic concentration and the resulting elution kinetics remains unclear. The purpose of this study was to characterize the release of daptomycin from PMMA cement and the subsequent effects on mechanical properties.Varying concentrations of daptomycin and tobramycin were vacuum mixed in commercially available PMMA and subjected to an in vitro elution period. High-performance liquid chromatography was used to quantify the concentration of the amount of daptomycin eluted at predetermined time points. Samples were subjected to compressive loading to analyze the effect of antibiotic concentration on cement mechanical properties. Daptomycin elution increased when initial tobramycin concentration was increased. Furthermore, the addition of antibiotics increased the compressive strength of the cement in the postelution period. The binary addition of tobramycin with daptomycin antibiotics modifies the elution and mechanical properties of PMMA bone cement. Based on the findings of our study, 2 g of daptomycin and 3.6 g of tobramycin per 40-g packet of cement should be used to promote daptomycin elution without sacrificing PMMA mechanical properties.
authors.affiliation: Department of Orthopaedic Surgery, Beaumont Health System, Royal Oak, Michigan 48073, USA.
authors.forename: Lige
authors.initials: L
authors.lastname: Kaplan
authors.forename: Michael
authors.initials: M
authors.lastname: Kurdziel
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Baker
authors.forename: James
authors.initials: J
authors.lastname: Verner
mesh_terms: D000900:Anti-Bacterial Agents; D001843:Bone Cements / Q000737:chemistry*; D019245:Compressive Strength; D017576:Daptomycin / Q000737:chemistry*; D004058:Diffusion; D004337:Drug Carriers / Q000737:chemistry*; D055119:Elastic Modulus; D006244:Hardness; D008422:Materials Testing; D019904:Polymethyl Methacrylate / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D001843:Bone Cements; D004337:Drug Carriers; D019904:Polymethyl Methacrylate; D017576:Daptomycin