Adhesion Behaviour of Primary Human Osteoblasts and Fibroblasts on Polyether Ether Ketone Compared with Titanium under In Vitro Lipopolysaccharide Incubation.

The aim of this in vitro pilot study was to analyse the adhesion behaviour of human osteoblasts and fibroblasts on polyether ether ketone (PEEK) when compared with titanium surfaces in an inflammatory environment under lipopolysaccharide (LPS) incubation. Scanning electron microscopy (SEM) images of primary human osteoblasts/fibroblasts on titanium/PEEK samples were created. The gene expression of the LPS-binding protein (LBP) and the LPS receptor (toll-like receptor 4; TLR4) was measured by real-time polymerase chain reaction (PCR). Immunocytochemistry was used to obtain evidence for the distribution of LBP/TLR4 at the protein level of the extra-cellular-matrix-binding protein vinculin and the actin cytoskeleton. SEM images revealed that the osteoblasts and fibroblasts on the PEEK surfaces had adhesion characteristics comparable to those of titanium. The osteoblasts contracted under LPS incubation and a significantly increased LBP gene expression were detected. This was discernible at the protein level on all the materials. Whereas no increase of TLR4 was detected with regard to mRNA concentrations, a considerable increase in the antibody reaction was detected on all the materials. As is the case with titanium, the colonisation of human osteoblasts and fibroblasts on PEEK samples is possible under pro-inflammatory environmental conditions and the cellular inflammation behaviour towards PEEK is lower than that of titanium.

Bisphosphonates and connexin 43: a critical review of evidence.

Bisphosphonates (BPs) are drugs commonly used in the treatment of various disease arising or affecting bone tissue. There is a standard use in bone neoplasia and metastasis, hormonal and developmental disorders as well as for compensation of adverse effects in several medical therapies. Many in-vivo and in-vitro studies have assessed the efficacy of this drug and its function in cellular scale. In this concern, BPs are described to inhibit the resorptive function of osteoclasts and to prevent apoptosis of osteoblasts and osteocytes. They can preserve the osteocytic network, reduce fracture rate, and increase the bone mineral content, which is therapeutically used. Connexin 43 (Cx43) is a crucial molecule for basal regulation of bone homeostasis, development, and differentiation. It is described for signal transduction in many physiological and pathological stimuli and recently to be involved in BP action.