Scientists have devised a ‘smart’ material that actively interacts with cells in the body to promote the growth of new bone. By attaching biological molecules to an otherwise inert polymer, Jeffrey Hubbell and colleagues produced an artificial material that mimics the body’s own extracellular matrix. The approach, described in the May issue of Nature Biotechnology, was tested in rats and may eventually be useful for healing injured bone or other tissues in human patients.
In one strategy for repairing damaged bone, tissue engineers are developing implants made of a scaffold material and specific proteins (such as BMPs) that coax cells to form new bone. Researchers have tried using extracellular matrix isolated from animals as the scaffold material, but these substances carry a risk of disease transmission and may provoke an immune reaction. Alternatively, researchers have used artificial scaffold materials, but these perform less well because they are passive carriers that do not interact with cells.
Hubbell and colleagues attached two different short protein sequences to an artificial scaffold. One sequence helps cells in the body adhere to the scaffold. The other sequence, which can be snipped in two by cellular enzymes, allows incoming cells to degrade the scaffold and enter new regions of the implant. The degradation of the scaffold in turn releases BMP proteins, stimulating more bone formation. The new scaffold material represents an advance in tissue engineering because it combines several advantages of both natural and artificial scaffolds.
Swiss Federal Institute of Technology and University of Zurich, Zurich, Switzerland
Tel: +41 1 632 4575
Also available online.
(C) Nature Biotechnology press release.
Message posted by: Trevor M. D'Souza