Antibiotic-free composite bone cements with antibacterial and bioactive properties. A preliminary study

Two bone cements (Palacos R® and Palacos LV®) based on polymethylmethacrylate (PMMA), clinically used in several cemented prosthetic devices, have been enriched with silver containing bioactive glass powders and compared with the plain commercial ones. The obtained composite cements have been subjected to a preliminary characterization by means of morphological and compositional analyses, compression mechanical tests, bioactivity test (by soaking into simulated body fluids), leaching tests and in vitro antibacterial test (count of colonies forming units, McFarland index evaluation, inhibition zone evaluation). The glass powders appeared uniformly dispersed inside the PMMA matrix and good mechanical properties (in compression) have been reached. The composite cements showed a bioactive behavior (since they developed hydroxyapatite on their surface after soaking in simulated body fluid) and a good antibacterial performance. The release of silver ions, which is the principal reason of antibacterial properties, is mainly reached after the first hours of contact with the leaching solution, as it is expected for a reasonable prevention of bacterial colonization during in vivo applications.