Biological response of human bone marrow mesenchymal stem cells to fluoride-modified titanium surfaces

Objectives The aim of the present study was to examine the behaviour of human bone marrow-derived mesenchymal stem cells (BM-MSC) to fluoride-modified grit-blasted (F-TiO) titanium surfaces compared with grit-blasted ones (TiO). Material and methods Implant surfaces were analysed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). BM-MSC were isolated from healthy donors and grown on the implant surfaces. Cell adhesion and proliferation, type I collagen (Col I) synthesis, osteoblastic differentiation (in terms of alkaline phosphatase activity, osteocalcin synthesis and extracellular matrix mineralization) were assessed. Furthermore, the ability to affect the osteoblastic/osteoclastic balance in terms of osteoprotegerin (OPG) and activator of nuclear factor kappa B ligand (RANKL) ratio was investigated. Results F-TiO surface showed higher S(a) values (P < 0.05) and the presence of nano-scale structures at the AFM and SEM analysis. Comparable cell morphology and similar adhesion values on both surfaces were detected at early time, whereas higher proliferation values on F-TiO samples were observed at 7 and 10 days. Increased Col I and OPG levels for cells grown on F-TiO were found, whereas RANKL was not detectable in any of the conditioned media. BM-MSC showed a similar expression of early and late osteogenic markers on both TiO and F-TiO surfaces. Conclusions The results of the present study show that the chemical and micro/nano-scale modifications induced by fluoride treatment of TiO-grit blasted surfaces stimulate the proliferation and the extracellular matrix synthesis by BM-MSC, as well as the increase of OPG synthesis, thus preventing osteoclast activation and differentiation. To cite this article:Guida L, Annunziata M, Rocci A, Contaldo M, Rullo R, Oliva A. Biological response of human bone marrow mesenchymal stem cells to fluoride-modified titanium surfaces.Clin. Oral Impl. Res. 21, 2010; 1234-1241.doi: 10.1111/j.1600-0501.2010.01929.x.