Papers by Author: R. Roest

Abstract: Titanium alloy has been used as a material for orthopaedic implants, however drawbacks still exist. Considerable efforts have been taken to modify the surface structure of the implant material and improve the biological performance. Previously we have demonstrated that biomaterials surface modification has a significant effect on the regulation of osteogenesis. We have investigated the behaviour of human osteoclasts on sol-gel coated carbonated hydroxyapatite on anodized titanium alloy. Osteoclasts cultured on the modified surface were able to attach and spread, exhibiting the characteristic peripheral brush border. Successful differentiation of the monocytes into osteoclasts and their attachment to the coated surface and the formation of resorption-like imprints indicated that carbonate hydroxyapatite (CHAP) coated titanium alloy play a significant role in regulating the functional activity of osteoclasts.

Abstract: In the biomedical field, the surface modification of titanium aims to inhibit wear, reduce corrosion and ion release, and promote biocompatibility. Sol-gel-derived ceramic nanoscale coatings show promise due to their relative ease of production, ability to form a physically and chemically uniform coating over complex geometric shapes, and their potential to deliver exceptional mechanical properties due to their nanocrystalline structure. In this study hydroxyapatite coatings on titanium were investigated for their fracture toughness.

Abstract: Poor cell adhesion to orthopaedic and dental implants results in implant failure. Establishing and maintaining mature bone at the bone/device interface is critical to the long-term success of the prostheses. Considerable effort has been devoted to alter the surface characteristics of these biomaterials in order to improve the initial interlocking of device and skeleton in the noncemented joint prosthesis. Previously we demonstrated that surface chemistry modification of bioceramics induced osteogenesis. In the present work, we investigate the effect of surface chemistry modification of titanium alloy (Ti-6Al-4V) with alkoxide-derived carbonate hydroxyapatite (CHAp) using sol-gel coating methods on human bone derived cell (HBDC)behaviour. Western blotting demonstrated that sol gel coating of Ti-6Al-4V with CHAp upregulated the expression of key signalling protein Shc isoforms (p46, p52, p66) and phosphorylated Erk1/2. CHAp-modification of Ti-6Al-4V is associated with signal transduction pathways involving the key signalling protein Shc and ERK1/2 which may lead to enhanced gene expression of extracellular matrix proteins at the skeletal tissue/device interface.