Evaluation of the physical and antimicrobial properties of silver doped hydroxyapatite depending on the preparation method.

In the present study, the effect of the preparation method on the physical and antibacterial properties of silver doped hydroxyapatite (HAp/Ag) samples was investigated. HAp/Ag with 0.1-5 % of silver was prepared using two different modified wet chemical precipitation methods. A comparison of thermal stability and thermodynamical properties indicated that the thermal stability and sintering temperature of HAp/Ag were higher than those of pure hydroxyapatite if Ca(NO3)2·4H2O, AgNO3, NH4OH and (NH4)2HPO4 were used as raw materials. Phase composition and silver release were determined by XRD and ICP-MS. The study showed that, after 50 h in simulated body fluid 0.8-1.8 % of silver of the total silver amount was released from compact HAp/Ag scaffolds, and release kinetics strongly depended on the HAp/Ag preparation method. In vitro antibacterial activity of samples from each method against the bacterial strains Staphylococcus epidermidis and Pseudomonas aeruginosa was approved. Results showed that, in the case of using Ca(OH)2, H3PO4 and AgNO3 as raw materials for HAp/Ag synthesis, higher antibacterial activity towards both bacterial strains could be obtained.