Flexible, silver containing nanocomposites for the repair of bone defects: antimicrobial effect against E. coli infection and comparison to tetracycline containing scaffolds

Bone regeneration in infected tissue or areas with high bacteria concentrations such as the oral cavity requires combining disinfection with biomaterial properties. Classical antibiotics typically provide excellent short term protection against re-infection of a defect but are typically washed out of an operation site within days. The present work investigates the use of silver on amorphous tricalcium phosphate (TCP) nanoparticles for electrospun, highly porous poly(lactide-co-glyclolide) (PLGA) fibrous composites. In vitro bioactivity tests of the wool-like composite PLGA/Ag-TCP (80 : 20) containing 0.5 wt% silver showed rapid hydroxyapatite deposition on the nanocomposite within 2 days. Antibacterial tests using E. coli demonstrated a strongly prolonged antibacterial effect of the scaffolds containing finely dispersed silver on TCP if compared to current clinically used methods based on soaking the scaffolds with a tetracycline solution prior to implantation.