Nanoparticles aid bone growth( In the first study of its kind bioen...),Health

In the first study of its kind, bioengineers and bioscientists at Rice University and Radboud University in Nijmegen, Netherlands, have shown they can grow denser bone tissue by sprinkling stick-like nanoparticles throughout the porous material used to pattern the bone.

The research is available online and slated to appear in the journal Bone. It's the latest breakthrough from the burgeoning field of tissue engineering. The new discipline combines the latest research in materials science and biomedical engineering to produce tissues that can be transplanted without risk of rejection.

To grow new bone, tissue engineers typically place bone cells on porous, biodegradable materials called scaffolds, which act as patterns. With the right chemical and physical cues, the cells can be coaxed into producing new bone. As the scaffold degrades, it is replaced by new bone.

"Ideally, a scaffold should be highly porous, nontoxic and biodegradable, yet strong enough to bear the structural load of the bone that will eventually replace it," said lead researcher Antonios Mikos, Rice's J.W. Cox Professor in Bioengineering, professor of chemical and biomolecular engineering and the director of Rice's Center for Excellence in Tissue Engineering. "Previous research has shown that carbon nanotubes give added strength to polymer scaffolds, but this is the first study to examine the performance of these materials in an animal model."

In the experiments, the researchers implanted two kinds of scaffolds into rabbits. One type was made of a biodegradable plastic called poly(propylene fumarate), or PPF, which has performed well in previous experiments. The second was made of 99.5 percent PPF and 0.5 percent single-walled carbon nanotubes. Nanotubes are about 80,000th the width of a hair. While they are normally about a thousand times longer than they are wide, the researchers used shorter segments that have fared well in prior cytocompatibility s
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