RESEARCH - Research points to ability to grow healthy new bone

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Research points to ability to grow healthy new bone

Rheumawire

Jul 28, 2005

Gandey

Nashville, TN - Biomedical engineers have demonstrated for the first time

that it is possible to grow healthy new bone without harvesting cells or

using growth factors. Using a deliberately created space within the body to

serve as a bioreactor, the group shows that the area reconstitutes with

functional living bone. " This is a radical departure from what others have

done, " senior author Dr Prasad Shastri (Vanderbilt University, Nashville,

TN) told rheumawire. He points out that unlike current practice in tissue

engineering, his group has shown that predictable volumes of bone can be

grown on demand. The study is scheduled to appear in an upcoming issue of

the Proceedings of the National Academy of Sciences [1].

" This will allow the clinician to have lots of control over outcome, "

Shastri said. " Surgeons will also be able to choose when to harvest bone,

depending on whether they need immature or mature bonethat kind of

flexibility is absolutely new. "

Shastri says this new regeneration approach may prove to be particularly

relevant for spinal-fusion applications where the quality of bone has a

tremendous impact on clinical outcomes. Currently, autologous bone is

considered the gold standard because of its ability to integrate with the

host bone and its lack of immune-related complications. But autologous bone

harvested from the iliac crest is associated with pain and long-term

discomfort. Shastri hopes this new procedure will one day offer an

alternative.

Studying New Zealand white rabbits, Shastri and his group created a space in

the tibia and expanded this area by injecting a biocompatible

calcium-alginate gel. They hypothesized that this bioreactor would invoke

the body's natural wound-healing response and would respond by filling the

space with new bone. They found that the bioreactor filled with healthy new

bone in about six weeks. They also found that the new bone could be easily

detached before fusing with the old bone, leaving the old bone scarred but

intact.

" The new bone actually has comparable strength and mechanical properties to

native bone, " lead author Dr Molly s told reporters. s is

currently at Imperial College in the UK, but she did most of this research

as a post-doctoral fellow at the Massachusetts Institute of Technology in

Cambridge. She added, " Since the harvested bone is fresh, it integrates

really well at a recipient site. "

The group plans to study the bioreactor in large animals next, and Shastri

told rheumawire that the group is working with Swiss collaborators looking

at the possibility of launching clinical trials in humans as early as next

year. " We are hoping to have preliminary clinical-trial data in the

not-so-distant future. " Shastri added that there are no regulatory issues

associated with this new procedure since the gel used to fill the bioreactor

is already in use.

Source

1. s MM, Marini RP, Schaefer D, et al. In vivo

engineering of organs: The bone bioreactor. Proc Natl Acad Sci 2005;

scheduled to appear online before print. Will be available at:

http://www.pnas.org/.

Not an MD

I'll tell you where to go!

Mayo Clinic in Rochester

http://www.mayoclinic.org/rochester

s Hopkins Medicine

http://www.hopkinsmedicine.org