Cure For Fractures and Breaks

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(Free-Press-Release.com) December 19, 2011 -- Cure For Fractures and Breaks

Friday, November 25th, 2011

For orthopedic surgeons large bone defects still pose a major challenge. Porous scaffolds are expected to solve this problem and to speed the healing process. These porous scaffolds mimic the properties of trabecular bone, which is mainly present at the end of long bones, near joints, where implants would be expected. Compared to the other main bone type, compact bone, trabecular bone has a higher surface area but is less dense, softer, weaker, and less stiff. When seeded with human cells and bone growth stimulating molecules, it enhance bone healing.

Over the past 20 years a wide variety of materials including ceramics, glass, metals, polymers and composites have been studied to be applied as a porous scaffold material. A recently released study, conducted by the Flemish Institute for Technological Research (VITO) and the company Janssen Pharmaceutica NV, both based in Belgium, focused on metallic and ceramic materials. In collaboration with the universities of Ghent and Leuven as part of the ‘Guided Bone Engineering’ project, the researchers produced porous titanium (Ti) and calcium phosphate (CaP) scaffolds by different manufacturing routes, all starting from powders.

Three manufacturing routes, the PU replica method, gelcasting and the 3DFD method, were used to process porous scaffolds with properties comparable with trabecular bone. Scaffold design was another important topic in the study. The goal was not only to develop an optimized internal porous architecture but also to obtain an implant design with a custom external shape tailored for each patient. The surface-modification research concentrated on the coating of metallic scaffolds with a CaP layer. The experiments aimed at an increased bioactivity of the metallic scaffolds and the use of this porous CaP layer as a drug delivery system for bone infections.
The results of this study show that the three routes allow the production of porous structures from a wide variety of materials with high pore interconnectivity. For Ti and its alloys, the mechanical properties are tuned towards these of porous bone. The versatility of the CaP coatings deposited onto the metallic surface led to an increased bioactivity and the possibility to act as a drug delivery system.

Thus magnesium is proven to be a biocompatible and bio-absorbable material. As a next step, the researchers began the production porous magnesium scaffolds; however, preliminary results, while promising, suggested that there are still problems to overcome before porous magnesium can be considered the ideal scaffold.

Bones     fractures     orthopedic