Antimicrobial activity and biocompatibility of Ag--(+) and Cu2+ -doped biphasic hydroxyapatite/alpha-tricalcium phosphate obtained from hydrothermally synthesized Ag+- and Cu2+ -doped hydroxyapatite

Abstract

Hydroxyapatite (HAp) powders doped with Ag+ or Cu2+ were synthesized by a hydrothermal method in order to obtain biomaterial with an antimicrobial effect. The synthesis was performed with two contents of dopant (Ag+ or Cu2+) by considering both the antimicrobial activities and biocompatibility of the powders. The doped HAp was annealed at 1200 C for 2 h with the intention of investigating the influence of doping with Ag+ and Cu2+ on the creation of the biphasic HAp/alpha-tricalcium phosphate (HAp/a-TCP) and determining the antimicrobial activity and biocompatibility of the obtained biphasic powders. Analyses of all powders, undoped and doped HAp and HAp/a-TCP, were performed by Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), atomic absorption spectroscopy (AAS) and energydispersive X-ray spectroscopy (EDS). The in vitro antibacterial activities of the powders were evaluated against: Staphylococcus aureus, Escherichia co li, Pseudomonas aeruginosa and Candida albi cans. All powders showed good antimicrobial activity but generally the powders of doped HAp/a-TCP had more uniform results against all pathogenic microorganisms than the powders of doped HAp. In vitro biocompatibility tests, MU and DET, were used to evaluate the biocompatibility of Ag+- and Cu2+-doped HAp/a-TCP with MRC-5 human fibroblast cells. These tests confirmed that powders do not have a cytotoxic effect. The HAp/a-TCP powders doped with the lower content of Ag+ and Cu2+ showed especially good biocompatibility. Antimicrobial and biocompatibility tests recommend the Ag+- and Cu2+-doped HAp/a-TCP as promising material for use in reconstructive surgery of bone.