In vitro assessment of antimicrobial activity of modified bone xenomaterials

Objective To assess antimicrobial characteristics of original bone xenomaterial implants with vancomycin impregnated with different technologies. Material and methods Bone xenomatrix was modified with two technologies of vancomycin adsorbed on the surface of the material and vancomycin adsorbed in the volume of the material through intermediate carrier. Antibiotic was impregnated using supercritical fluid extraction with carbon dioxide. Antibiotic release from modified xenomaterial was evaluated and antimicrobial activity against S. aureus assessed in vitro. Results Elution of vancomycin over 24 hours from the material produced with absorption technology was 98 % of baseline content in the matrix. Residual content of antibiotic was 1.75 % on average. The use of intermediate carrier (L/D polylactide isomer) allows for obtaining material with gradual prolong vancomycin release. Major release (68.16 % from baseline content) of vancomycin occurred smoothly over the first 14 days. Bone block eluted 22 % of the residual antibiotic load by 30 days of incubation. The products impregnated with antibiotic using two different technologies exhibited evident antimicrobial activity against S. aureus. Conclusion Technologies developed to impregnate vancomycin in xenogenic bone matrix are practical to obtain new modified bone grafting material with evident antimicrobial activity.