Dirk Bormann

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The aim of this study was to investigate the differences in the in vivo degradation behaviour of magnesium implants with various grain sizes and damaged surfaces. For this purpose, three different LAE442 magnesium implants were produced: cast, single and double extruded implants, in order to obtain different grain sizes. Furthermore, defects were positioned(More)
In former studies the magnesium alloy LAE442 showed promising in vivo degradation behavior and biocompatibility. However, reproducibility might be enhanced by replacement of the rare earth composition metal "E" by only a single rare earth element. Therefore, it was the aim of this study to examine whether the substitution of "E" by neodymium ("Nd") had an(More)
In magnesium alloys, the components used modify the alloy properties. For magnesium implants in contact with bone, rare earths alloys are commonly examined. These were shown to have a higher corrosion resistance than other alloys and a high mechanical strength, but their exact composition is hard to predict. Therefore a reduction of their content could be(More)
Nondestructive, high-resolution 3-dimensional (3D) imaging of the embryonic heart remains a challenge in cardiovascular development research. In the past, several imaging techniques (eg, magnetic resonance microscopy, optical coherence tomography) were tested for their suitability to visualize the 3D morphology of embryonic hearts. Most of these imaging(More)
The osteoinductivity of human growth-and-differentiation factor-5 (GDF-5) is well established, but a reduced amount of ectopic bone is formed compared to other members of the bone morphogenetic protein (BMP) family like BMP-2. We hypothesized that swap of two BMP-receptor-interacting residues of GDF-5 to amino acids present in BMP-2 (methionine to valine at(More)
MgCa0.8 cylinders (2.5 x 25 mm(2)) were coated with a magnesium-fluoride layer and implanted in the marrow cavities of both tibiae of 10 New Zealand White rabbits. The implantation duration was 3 and 6 months. The implants were clinically well tolerated. Micro-computed tomography revealed a new bone formation at the edges of the implants as well as an(More)
BACKGROUND Most studies on biodegradable magnesium implants published recently use magnesium-calcium-alloys or magnesium-aluminum-rare earth-alloys.However, since rare earths are a mixture of elements and their toxicity is unclear, a reduced content of rare earths is favorable. The present study assesses the in vivo biocompatibility of two new magnesium(More)
The aim of this study was to compare the biomechanical properties of degradable magnesium calcium alloy (MgCa0.8) screws and commonly used stainless steel (S316L) screws and to assess the in vivo degradation behavior of MgCa0.8. MgCa0.8 screws (n=48) and S316L screws (n=32) were implanted into both tibiae of 40 adult rabbits for a follow-up of 2, 4, 6 and 8(More)
Magnesium alloys as degradable implant materials in orthopaedic research received a lot of interest in recent years (Witte et al., 2007a; Xu et al., 2008; Zhang et al., 2010). The application of resorbable implant material avoids an implant removal surgery and therewith helps to diminish the costs and the burden for the patient. In comparison to other(More)