The term DLC (diamond-like carbon) describes a whole class of different biocompatible materials based on amorphous carbon. One possible application for DLC is the coating of artificial hip joints to increase their life expectancy. The life expectancy of artificial hip joints is limited by osteolysis caused by wear particles, especially by wear particles in a range from 0.3 mu m to 10 mu m. In this study, biocompatible steel substrates are coated with DLC. Coatings with different structure are produced and investigated regarding their wear behavior. The aim is to influence the wear particle size distribution. To improve the adhesion of the coatings on the substrate, metallic interface layers are deposited by cathodic vacuum arc deposition, comparing chromium and titanium as interface layer material. The DLC-coatings are deposited by a vacuum arc that allows a transition from cathodic to anodic operation mode.It is shown, that by varying the deposition process parameters and thus by variation of the film properties, the wear particle size distribution can be adjusted significantly.

Background Transfersome(R) is a drug delivery technology based on highly deformable, ultraflexible lipid vesicles which penetrate the skin when applied non-occlusively.Objectives To assess the advantages of this carrier-based formulation in humans, the efficacy and the atrophogenic potential of triamcinolone acetonide (TAC) in Transfersome(R) was compared with commercially available TAC-containing cream and ointment.Methods Healthy volunteers were enrolled in double-blind, placebo-controlled clinical trials with random study medication assignment to the test areas.Results A 10-fold lower dose of TAC in Transfersome(R) (2.5 mug cm(-2)) was bioequivalent to 25 mug cm(-2) TAC in conventional formulations as measured by erythema suppression ( cream: P = 0.01, ointment: P < 0.001). A skin blanching assay revealed different kinetics of the formulations, with a delayed onset of action of the Transfersome(R) and ointment preparations. Ultrasonic measurements revealed a significantly reduced atrophogenic potential. There was a 12.1% reduction in skin thickness given by TAC in Transfersome(R) compared with a 21.1% reduction given by a bioequivalent dose in TAC cream after a 6-week treatment period (P = 0.007).Conclusions Transfersome(R) may significantly improve the risk - benefit ratio of topically applied glucocorticosteroids.