Ceramic scaffolds enriched with gentamicin loaded poly(lactide-co-glycolide) microparticles for prevention and treatment of bone tissue infections

• Immobilization of gentamicin loaded microparticles with cross-linked sodium alginate within titanium dioxide scaffolds
• Evaluation of drug release profile, antibacterial properties and potential cytotoxicity
• The system assures desired drug release profile within 50 days
• The system is active against Staphylococcus spp. and cytocompatible with osteoblast-like cells

Bone scaffolds are susceptible for bacterial infection when implanted, particularly in compromised bone. Therefore anti-bacterial bone scaffolds are desirable. Here a novel approach to provide bactericidal properties for titanium dioxide scaffolds is proposed. Gentamicin loaded poly(L-lactide-co-glycolide) microparticles were immobilized on the scaffold pore walls by sodium alginate hydrogel. The results show that the microparticles were effectively immobilized on the scaffolds. Desired burst release was observed within the first 8 h and gentamicin dose reached 125 μg from single scaffold that corresponded to ~ 25% of total drug introduced in the system. Following the initial burst, the dose was gradually decreasing up to day 10 and afterwards a sustained release of 3 μg/day was measured. Cumulatively ~ 90% of the drug was delivered up to day 50. Above pattern, i.e. burst release with following sustained release, is desired for prevention of perioperative bone infections: burst release stops local infections during post-implantation “decisive period” while further sustained drug release prevents bacterial recolonization. In vitro studies confirmed antimicrobial activity of released gentamicin against Staphylococcus spp. and cytocompatibility of the system with osteoblast-like cells (MG-63). Thus the system is a viable option for the treatment of bone tissue defects.