Antibacterial poly(D,L-lactic acid) coating of medical implants using a biodegradable drug delivery technology.
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.
Gollwitzer
Hans
H
Institut für Experimentelle Onkologie und Therapieforschung, Technischen Universität München, Ismaninger Strasse 22, 81675 Munich, Germany. h.gollwitzer@ltz.tu-muenchen.de
Ibrahim
Karim
K
Meyer
Henriette
H
Mittelmeier
Wolfram
W
Busch
Raymonde
R
Stemberger
Axel
A
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
D000900:Anti-Bacterial Agents; D011091:Polyesters; C033616:poly(lactide)