Antibiotic-loaded phosphatidylcholine inhibits staphylococcal bone infection.
OBJECTIVE
To test antibiotic-loaded coating for efficacy in reducing bacterial biofilm and development of osteomyelitis in an orthopaedic model of implant infection.


METHODS
Phosphatidylcholine coatings loaded with 25% vancomycin were applied to washed and sterilized titanium wires 20 mm in length. A 10 mm segment was removed from rabbit radius (total = 9; 5 coated, 4 uncoated), and the segment was injected with 1 × 10(6) colony forming units (CFUs) of Staphylococcus aureus (UAMS-1 strain). Titanium wires were inserted through the intramedullary canal of the removed segment and into the proximal radial segment and the segment was placed back into the defect. After 7 d, limbs were removed, X-rayed, swabbed for tissue contamination. Wires were removed and processed to determine attached CFUs. Tissue was swabbed and streaked on agar plates to determine bacteriological score.


RESULTS
Antibiotic-loaded coatings resulted in significantly reduced biofilm formation (4.7 fold reduction in CFUs; P < 0.001) on titanium wires and reduced bacteriological score in surrounding tissue (4.0 ± 0 for uncoated, 1.25 ± 0.5 for coated; P = 0.01). Swelling and pus formation was evident in uncoated controls at the 7 d time point both visually and radiographically, but not in antibiotic-loaded coatings.


CONCLUSIONS
Active antibiotic was released from coated implants and significantly reduced signs of osteomyelitic symptoms. Implant coatings were well tolerated in bone. Further studies with additional control groups and longer time periods are warranted. Antibiotic-loaded phosphatidylcholine coatings applied at the point of care could prevent implant-associated infection in orthopaedic defects.
Jessica Amber Jennings, Warren O Haggard, Department of Biomedical Engineering, University of Memphis, Memphis, TN 38152, United States.
Jessica Amber
JA
Jennings
Jessica Amber Jennings, Warren O Haggard, Department of Biomedical Engineering, University of Memphis, Memphis, TN 38152, United States.
Karen E
KE
Beenken
Jessica Amber Jennings, Warren O Haggard, Department of Biomedical Engineering, University of Memphis, Memphis, TN 38152, United States.
Robert A
RA
Skinner
Jessica Amber Jennings, Warren O Haggard, Department of Biomedical Engineering, University of Memphis, Memphis, TN 38152, United States.
Daniel G
DG
Meeker
Jessica Amber Jennings, Warren O Haggard, Department of Biomedical Engineering, University of Memphis, Memphis, TN 38152, United States.
Mark S
MS
Smeltzer
Jessica Amber Jennings, Warren O Haggard, Department of Biomedical Engineering, University of Memphis, Memphis, TN 38152, United States.
Warren O
WO
Haggard
Jessica Amber Jennings, Warren O Haggard, Department of Biomedical Engineering, University of Memphis, Memphis, TN 38152, United States.
Karen S
KS
Troxel
Antibiotic; Biofilm; Drug delivery coating; Implant; Orthopaedic infection