title: Antibacterial poly(D,L-lactic acid) coating of medical implants using a biodegradable drug delivery technology.
abstract: OBJECTIVE
  Biomaterial-associated bacterial infections present common and challenging complications with medical implants. The purpose of this study was to determine the antibacterial properties of a low molecular weight biodegradable poly(D,L-lactic acid) coating with integrated antibiotics gentamicin and teicoplanin.
  
  
  METHODS
  Coating of Kirschner-wires was carried out by a solvent casting technique under aseptic conditions with and without incorporated antibiotics. Release kinetics of gentamicin and teicoplanin were studied in phosphate-buffered saline. Initial bacterial adhesion of Staphylococcus epidermidis on coated and bare implants was determined by radiolabelling and counts of detached viable organisms.
  
  
  RESULTS
  The incorporated antibiotics showed a continuous release over a period of at least 96 h with an initial peak of release in the first 6 h. Attachment of non-viable microorganisms, detected by radiolabelled bacteria, was increased significantly by the polymer coatings (P < 0.05). In contrast, the number of viable bacteria was reduced by the pure polymer (P < 0.01) and further by the polymer-antibiotic combinations (P < 0.05).
  
  
  CONCLUSIONS
  Poly(D,L-lactic acid) coating of implants could offer new perspectives in preventing biomaterial-associated infections. Combinations with other drugs to formulate custom-tailored implant surfaces are feasible.
authors.affiliation: Institut für Experimentelle Onkologie und Therapieforschung, Technischen Universität München, Ismaninger Strasse 22, 81675 Munich, Germany. h.gollwitzer@ltz.tu-muenchen.de
authors.forename: Hans
authors.initials: H
authors.lastname: Gollwitzer
authors.forename: Karim
authors.initials: K
authors.lastname: Ibrahim
authors.forename: Henriette
authors.initials: H
authors.lastname: Meyer
authors.forename: Wolfram
authors.initials: W
authors.lastname: Mittelmeier
authors.forename: Raymonde
authors.initials: R
authors.lastname: Busch
authors.forename: Axel
authors.initials: A
authors.lastname: Stemberger
mesh_terms: D020341:Absorbable Implants; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics; D001673:Biodegradation, Environmental / Q000187:drug effects; D001864:Bone Wires; D016503:Drug Delivery Systems / Q000379:methods*; D006801:Humans; D011091:Polyesters / Q000008:administration & dosage* / Q000493:pharmacokinetics; D013212:Staphylococcus epidermidis / Q000187:drug effects* / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D011091:Polyesters; C033616:poly(lactide)