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Since bacterial infection is a rising complication following the wide use of implant, there is considerable attention on the effect of implant surface properties on bacterial adhesion. In this study, the effect of silver (Ag) doped hydroxyapatite (HA) coatings on initial antibacterial adhesion and osteoblast cell proliferation and differentiation was investigated. Using a sol-gel process, HA coatings doped with 1 wt % AgNO(3) (AgHA1.0) and 1.5 wt % Ag (AgHA1.5) were prepared. Coated surfaces were characterized using X-ray diffraction (XRD) and contact angles measurements. The initial bacteria adhesion was evaluated using a RP12 strain of Staphylococcus epidermidis (ATCC 35984) and the Cowan I strain of Staphylococcus aureus, whereas osteoblast proliferation and differentiation were evaluated using human embryonic palatal mesenchyme cells (HEPM), an osteoblast precursor cell line. In this study, XRD analysis of all surfaces indicated peaks corresponding to HA. Contact angles for AgHA surfaces were observed to be significantly lower when compared to HA surfaces. In vitro initial bacterial adhesion study indicated a significantly reduced number of S. epidermidis and S. aureus on AgHA surfaces when compared to HA surface. The use of HEPM cells indicated no significant difference in double-stranded DNA (dsDNA) production between all surfaces. Additionally, no differences in alkaline phosphatase specific activity were observed between HA and AgHA1.0 surfaces. Overall, it was concluded that AgHA1.0 has the similar biological activity as HA, with respect to bone cell proliferation and differentiation. In addition, the AgHA1.0 was also concluded to have the ability to minimize the initial bacteria adhesion. (c) 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007.

No abstract

The aim of this study was to prepare a novel titanium-10tantalum-10niobium (Ti-Ta-Nb) alloy nanoscale coatings using sputter deposition and to evaluate their effect on osteoblast response. The three groups of Ti alloy used in this study were: (1) as-sputtered Ti-Ta-Nb coatings; (2) Ti-Ta-Nb disks; and (3) Ti6Al4V alloy disks as controls. The three surfaces were characterized using a x-ray diffractometer, a scanning electron microscope, a surface profilometer, and a contact angle measuring instrument. ATCC CRL 1486 human embryonic palatal mesenchymal cells were used to evaluate the cell responses. Cell attachment was measured using a coulter counter. After 4 days incubation, dsDNA, total protein, and alkaline phosphatase of the attached cells were assayed. The as-sputtered Ti-Ta-Nb coatings consisted of dense nanoscale grains. The Ti-Ta-Nb coatings exhibited significantly greater cell attachments compared to the two polished microgroove groups at 30minutes and 1hour. No significant differences were observed in dsDNA amount, total protein production and alkaline phosphatase specific activity among the three groups. These results demonstrated an equivalent performance for the Ti-Ta-Nb alloy and its nanoscale Ti-Ta-Nb coatings, suggesting an alternative biocompatible metal for use in dentistry and orthopedics.