title: Mechanical properties and drug release behavior of bioactivated PMMA cements.
abstract: Septic loosening of cemented implants represents an unresolved long-term problem of total hip endoprostheses. Common treatments of infected prostheses involve the use of temporary antibiotic-loaded PMMA spacer-implants or antibiotic-loaded cements. The latter are either provided by a manufacturer or are obtained by simply mixing specific antibiotic powders according to a microbial sensitivity test with PMMA cement. This study is aimed to investigate the antibiotic release behavior and mechanical properties of novel modified PMMA cements, which were bioactivated by chemical modification of commercial cements with either 0.5% hydroxyethylmethacrylate-phosphate (HEMA-P) or 0.5% hydroxyethylmethacrylate-phosphate + calcium chloride and sodium carbonate as buffer. Tobramycin release experiments from the cements were performed statically by immersion of the drug-loaded samples in PBS buffer following liquid change after different periods of time or during cyclic mechanical loading of the cement samples. Cement modification did not significantly alter the mechanical properties of the cements, but affected the release rate from the matrix. While the unmodified cement released approximately 0.33 mg/cm(2) tobramycin after 48 h independent of the testing regime, modification with both HEMA-P and salt buffer increased the antibiotic release to 37-50 mg/cm(2) when tested under cyclical mechanical loading.
authors.affiliation: Department for Functional Materials in Medicine and Dentistry University of Würzburg, Würzburg Germany. elke.vorndran@fmz.uni-wuerzburg.de
authors.forename: Elke
authors.initials: E
authors.lastname: Vorndran
authors.forename: Nikola
authors.initials: N
authors.lastname: Spohn
authors.forename: Berthold
authors.initials: B
authors.lastname: Nies
authors.forename: Sophie
authors.initials: S
authors.lastname: Rössler
authors.forename: Sandra
authors.initials: S
authors.lastname: Storch
authors.forename: Uwe
authors.initials: U
authors.lastname: Gbureck
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D001843:Bone Cements / Q000737:chemistry*; D002122:Calcium Chloride / Q000737:chemistry; D002254:Carbonates / Q000737:chemistry; D019245:Compressive Strength; D003692:Delayed-Action Preparations / Q000737:chemistry*; D055119:Elastic Modulus; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D014031:Tobramycin / Q000008:administration & dosage*
chemical_list: D000900:Anti-Bacterial Agents; D001843:Bone Cements; D002254:Carbonates; D003692:Delayed-Action Preparations; D008689:Methacrylates; C005686:sodium carbonate; C005044:hydroxyethyl methacrylate; D019904:Polymethyl Methacrylate; D002122:Calcium Chloride; D014031:Tobramycin