Sm:HAp nanopowders present antibacterial activity against Enterococcus faecalis

Abstract

The synthesis of nanoparticles with inhibitory and bactericidal effects represents a great interest in development of new materials for biological applications. In this paper we present for the first time the synthesis of Ca10-xSmx(PO4)6(OH)2 nanoparticles at low temperature and primary tests concerning the adherence of Enterococcus faecalis ATCC 29212 (gram-positive bacteria). All the XRD peaks were indexed in accordance with the hexagonal HAp in P63m space group. The EDAX spectrum and elemental mapping of O, P, Ca, and Sm demonstrate that all the elements were homogeneously distributed in Ca10-xSm x(PO4)6(OH)2 with x Sm=0.03. The peaks at 347.3 eV, 532.1 eV, and 133.8 eV in the XPS spectra can be attributed to the binding energy of Ca 2p, O 1s, and P 2p. The peak at 1084.4 eV observed in Ca10-xSmx(PO 4)6(OH)2 was attributed to the Sm 3d 5/2. Bacterial adhesion was reduced on Ca10-xSm x(PO4)6(OH)2 sample when compared to pure HAp (xSm=0) and significant differences in bacterial adhesion on pure HAp (x=0) and Sm:HAp (xSm=0.01, xSm=0.03, and xSm=0.1) were observed. The bacterial adhesion decreased when the samarium concentrations increased. Finally, we demonstrate that the Sm:HAp nanopowder with xSm>0 showed high antibacterial activity against Enterococcus faecalis ATCC 29212. © 2014 Carmen Steluta Ciobanu et al.