Interleukin (IL)-1β is one of the major pathogenic regulators during the pathological development of intervertebral disc degeneration (IDD). However, effective treatment options for IDD are limited. Suramin is used to treat African sleeping sickness. This study aimed to investigate the pharmacological effects of suramin on mitigating IDD and to characterize the underlying mechanism. Porcine nucleus pulposus (NP) cells were treated with vehicle, 10 ng/ml IL-1β, 10 μM suramin, or 10 μM suramin plus IL-1β. The expression levels of catabolic and anabolic proteins, proinflammatory cytokines, mitogen-activated protein kinase (MAPK), and nuclear factor (NF)-κB-related signalling molecules were assessed by Western blotting, quantitative real-time polymerase chain reaction (qRT-PCR), and immunofluorescence analysis. Flow cytometry was applied to detect apoptotic cells. The ex vivo effects of suramin were examined using IDD organ culture and differentiation was analyzed by Safranin O-Fast green and Alcian blue staining.Aims
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Bioresorbable orthopaedic devices with calcium phosphate (CaP) fillers are commercially available on the assumption that increased calcium (Ca) locally drives new bone formation, but the clinical benefits are unknown. Electron beam (EB) irradiation of polymer devices has been shown to enhance the release of Ca. The aims of this study were to: 1) establish the biological safety of EB surface-modified bioresorbable devices; 2) test the release kinetics of CaP from a polymer device; and 3) establish any subsequent beneficial effects on bone repair ActivaScrew Interference (Bioretec Ltd, Tampere, Finland) and poly(L-lactide-co-glycolide) (PLGA) orthopaedic screws containing 10 wt% β-tricalcium phosphate (β-TCP) underwent EB treatment. Objectives
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Loosening is a well-known complication in the fixation of fractures using devices such as locking plates or unilateral fixators. It is believed that high strains in the bone at the bone-screw interface can initiate loosening, which can result in infection, and further loosening. Here, we present a new theory of loosening of implants. The time-dependent response of bone subjected to loads results in interfacial deformations in the bone which accumulate with cyclical loading and thus accentuates loosening. We used an ‘ideal’ bone-screw system, in which the screw is subjected to cyclical lateral loads and trabecular bone is modelled as non-linear viscoelastic and non-linear viscoelastic-viscoplastic material, based on recent experiments, which we conducted.Aims
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