Antibacterial and osteogenic properties of silver-containing hydroxyapatite coatings produced using a sol gel process

摘要

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 hy-droxyapatite (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 percent AgNO_3 (AgHAl.0) and 1.5 wt percent 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 phospha-tase specific activity were observed between HA and AgHAl.0 surfaces. Overall, it was concluded that AgHAl.0 has the similar biological activity as HA, with respect to bone cell proliferation and differentiation. In addition, the AgHAl.0 was also concluded to have the ability to minimize the initial bacteria adhesion.