Antibacterial Ag-doped glass-ceramic scaffolds

A bioactive and fluoroapatite-containing glass-ceramic was used to realize scaffolds (Fa-GC) with the polymeric sponge method. In order to confer antibacterial properties, silver was introduced in the material (Ag-Fa-GC) through a patented ion-exchange process. Scaffolds structure, morphology and composition were characterized through XRD, SEM and EDS analyses; the total porosity, the pore size and the degree of pore interconnection were respectively investigated by means of density measurement, image analysis and capillarity test. The mechanical strength was estimated through compressive test. Released Ag ions were evaluated using the GFAAS analysis and in vitro tests were performed soaking Ag- and Fa-GC in SBF solution. Antibacterial properties were verified through the dilution broth test and the measurement of inhibition zone, using a S. Aureus standard stock. Osteoblasts cultures were realized to investigate material biocompatibility and Ag effect. Fa-GC with an open and interconnected porosity and a compression strength of 2.0 ± 0.6 MPa were successfully obtained. Ag-Fa-GC maintain their bioactivity after the ion-exchange treatment and the introduced Ag was gradually released in SBF. The Ag-Fa-GC showed a good antibacterial behaviour, since they are able to create a significant inhibition halo and limit the bacterial proliferation. Nevertheless the preliminary cytotoxicity test showed that Ag presence affects cells proliferation and viability.