Tuesday, December 6, 2011

Bone Fabricated By Printing

I have seen plenty of work on using printing technology to build up 3D structures with nothing very convincing to show for it.  Here we see a bone scaffold produced that is then put in a bath of immature bone cells that then populate the scaffold.  When this is finished we have a convincing bone that is also possibly stronger than natural bone.

Taking this all a step further, we can use this to experiment with placing carbon nanotubes into the powder to form an even stronger matrix.  We saw evidence of this in the thin section work done on the starchild skull.

For now we have a way to replace missing bone that appears to do the job rather well.

3D printer used to make bone-like material

Tuesday, Nov. 29, 2011
By Eric Sorensen, WSU science writer

PULLMAN, Wash. - It looks like bone. It feels like bone. For the most part, it acts like bone.

And it came off an inkjet printer.

Washington State University researchers have used a 3D printer to create a bone-like material and structure that can be used in orthopedic procedures, dental work and to deliver medicine for treating osteoporosis. Paired with actual bone, it acts as a scaffold for new bone to grow on and ultimately dissolves with no apparent ill effects.

The authors report on successful in vitro tests in the journal Dental Materials and say they’re already seeing promising results with in vivo tests on rats and rabbits. It’s possible that doctors will be able to custom order replacement bone tissue in a few years, said Susmita Bose, co-author and professor in WSU’s School of Mechanical and Materials Engineering.

"If a doctor has a CT scan of a defect, we can convert it to a CAD file and make the scaffold according to the defect,” Bose said.

The material grows out of a four-year interdisciplinary effort involving chemistry, materials science, biology and manufacturing. A main finding of the paper is that the addition of silicon and zinc more than doubled the strength of the main material, calcium phosphate.

The researchers – who include mechanical and materials engineering Professor Amit Bandyopadhyay, doctoral student Gary Fielding and research assistant Solaiman Tarafder - also spent a year optimizing a commercially available ProMetal 3D printer designed to make metal objects.

The printer works by having an inkjet spray a plastic binder over a bed of powder in layers of 20 microns, about half the width of a human hair. Following a computer’s directions, it creates a channeled cylinder the size of a pencil eraser.

After just a week in a medium with immature human bone cells, the scaffold was supporting a network of new bone cells.

The research was funded with a $1.5 million grant from the National Institutes of Health.

Susmita Bose, WSU School of Mechanical and Materials Engineering, 509-335-7461, sbose@wsu.edu

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