Purpose: This study compared the degradation profile, safety, and efficacy of bioresorbable magnesium alloy and polylactide-co-glycolide (PLGA) polymer osteosynthesis systems for the treatment of fractures in a load-sharing maxillofacial environment using a new mini-swine fracture fixation model.
Materials And Methods: Two types of clinically relevant situations were evaluated in 5 Yucatan miniature pigs. Defined porcine midface osteotomies of the supraorbital rim and zygoma were created and fixed with either a coated magnesium (test animals) or PLGA plate and screw osteosynthesis system (control animals).
Magnesium alloys are candidates for resorbable material in bone fixation. However, the degradation and performance of osteosynthesis plate/screw systems in vivo, under cyclic deformation, is unknown. We evaluated the outcomes of human standard-sized magnesium plate/screw systems with or without plasma-electrolytic surface modifications in a miniature pig rib model.
View Article and Find Full Text PDFMater Sci Eng C Mater Biol Appl
December 2016
Self-tapping of magnesium screws in hard bone may be a challenge due to the limited torsional strength of magnesium alloys in comparison with titanium. To avoid screw failure upon implantation, the new concept of a rivet-screw was applied to a WE43 magnesium alloy. Hollow cylinders with threads on the outside were expanded inside drill holes of minipig mandibles.
View Article and Find Full Text PDFBiodegradable magnesium plate/screw osteosynthesis systems were implanted on the frontal bone of adult miniature pigs. The chosen implant geometries were based on existing titanium systems used for the treatment of facial fractures. The aim of this study was to evaluate the in vivo degradation and tissue response of the magnesium alloy WE43 with and without a plasma electrolytic surface coating.
View Article and Find Full Text PDFObjective: To evaluate metal artifacts induced by biodegradable magnesium--a new class of degradable biomaterial that is beginning to enter the orthopedic routine--on CT and MRI compared to standard titanium and steel controls.
Methods: Different pins made of titanium, stainless steel, and biodegradable magnesium alloys were scanned using a second-generation dual-energy multidetector CT and a 1.5-T MR scanner.
Recent findings in neuroscience have shown differential patterns in brain activity in response to similar stimuli and activities across cultural and social differences. This calls for a framework to understand how such differences may come to be implemented in brains and neurons. Based on strands of research in social anthropology, we argue that human practices are characterized by particular patterns, and that participating in these patterns orders how people perceive and act in particular group- and context-specific ways.
View Article and Find Full Text PDFPrevious research on the feasibility of using biodegradable magnesium alloys for bone implant applications mainly focused on biocompatibility and corrosion resistance. However, successful clinical employment of endosseous implants is largely dependent on biological fixation and anchorage in host bone to withstand functional loading. In the present study, we therefore aimed to investigate whether bone-implant interface strength and osseointegration of a novel biodegradable magnesium alloy (Mg-Y-Nd-HRE, based on WE43) is comparable to that of a titanium control (Ti-6Al-7Nb) currently in clinical use.
View Article and Find Full Text PDFActa Biomater
September 2009
Poly(methyl methacrylate) (PMMA) remains the most common bone substitute material used for vertebroplasty. A possible downside with this material is that the Young's modulus of the cement is significantly higher than that of osteoporotic vertebral cancellous bone. In consequence, an increased fracture risk has been demonstrated for the adjacent vertebral bodies after reinforcement.
View Article and Find Full Text PDFLarge bony defects often show a delayed healing and have an increasing risk of infection. Several materials are used for the coverage of large defects. These materials must be biocompatible, easy to use, and must have an appropriate stability to present a mechanical hindrance.
View Article and Find Full Text PDFTo exploit advances in proteomics for drug discovery, high-throughout methods for target validation that directly address the cellular roles of proteins are required. To do this, we have characterized fluorophore-assisted light inactivation (FALI) which uses coherent or diffuse light targeted by fluorescein-labeled probes to inactivate specific proteins. We have shown that it is spatially restricted and tested its efficacy in living cells.
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