Antibacterial and Bioactive Composite Bone Cements

Background: Peri-prosthetic infections are characterized by high resistance to systemic antibiotic therapy. In this work, commercial PMMA-based bone cement has been loaded with a bioactive glass doped with silver ions, with the purpose to prepare composite bone cement containing a single inorganic phase with both bioactive and antibacterial properties, able to prevent bacterial contamination. Methods: The glass distribution in the polymeric matrix, the composites radio-opacity, the bending strength and modulus, the morphology of the fracture surfaces, the bioactivity in Simulated Body Fluid (SBF) and the antibacterial effect were evaluated. The glass particles dispersion in the polymeric matrix and their exposition on the polymer surface have been assessed by morphological and compositional characterizations via Scanning Electron Microscopy (SEM) and Energy Dispersion Spectroscopy (EDS). Results: The introduction of the silver-doped bioactive glass allowed imparting an intrinsic radio-opacity to the cement. The bending strength and modulus were influenced by the glass preparation, amount and grain-size. The polymeric matrix did not affect the composite ability to induce hydroxyapatite precipitation on its surface (bioactivity). Moreover, antibacterial test (inhibition halo evaluation) revealed a significant antibacterial effect toward S. aureus, Bacillus, E. coli and C. albicans strains. Conclusion: The obtained results motivate further investigations and future in vivo tests.