By Nicholas Smith, Inside Tucson Business
Published on Friday, September 04, 2009
When Brandi Tellis started school, she had no idea that she’d soon help develop Plasti-Bone, this century’s version of the metal plate used to treat head wounds.
After getting a look at what the medical field was like, she instead opted to study engineering at the University of Arizona’s Materials Science department, not thinking she’d end up in her current field.
“I thought I’d be involved with NASA or something, I never intended to get involved in biomedical materials,” she said.
Brandi Tellis, left, a reseach engineer at BAE Systems, holds a sample of Plasti-Bone, a gauze-like structure that helps the body regrow bone.
That all changed when her grandmother had an accident and needed orthopedic surgery.
“At the same time that happened to her I was taking a class in biomaterials and I was seeing what they were talking about in class and seeing it in my grandmother’s experience in this bionic knee,” she said.
When there was no space left in her professor’s lab, Tellis was directed to an internship at Advanced Ceramics Research, which lead to her current position as a research engineer.
Medical implants may seem like a strange project for a facility that primarily caters to robotic planes.
“This was something that was up ACR’s alley,” she said. “We have used composite materials intended to go inside the body as opposed to on the surface of a drill bit.”
The company’s Silver Fox aerial vehicle project originally grew out of a ceramics and lightweight materials business. Advanced Ceramics Research was bought out earlier this year by BAE Systems. Its Tucson location at 3292 E. Hemisphere Loop is now known as the Unmanned Aircraft Project Office.
Now, three years after getting her masters in biomedical engineering, Tellis’ Plasti-Bone project aims regrow bones in a skull after a serious injury by developing a kind of internal cast.
“That’s why I call it a scaffold, it’s a framework that allows those tissues to come in and do their thing,” Tellis said.
Plasti-Bone feels like a gauzy cast and is made out of the same materials already used in sutures and bone screws which make it more likely to get approval.
The material is able to be absorbed because it’s made from biocompatible polymers, which can be broken down into carbon dioxide and lactic acid, two things the body naturally gets rid of.
Another advantage of Plasti-Bone’s porous nature is it allows medication to fully penetrate it, unlike titanium and plastics.
“With blood vessels, if you give a patient antibiotics either by pills or IV, the antibiotics can travel all through the blood stream and can travel every hidden site, and so you won’t have these sites where bacteria will sort of hide,” Tellis said.
Head injuries with missing skull pieces are currently treated in one of two ways: with a titanium plate or with a type of plastic called PMMA. Titanium is advantageous because more is known about it and it is widely used, but it is stiffer and causes the adjacent bone to regress. PMMA on the other hand, doesn’t degrade or have the mismatch that titanium has, but it is prone to infection.
The ideal solution is to have the body re-grow tissue and bone over the wound, but this is next to impossible without the framework provide by Plasti-Bone, which allows blood to bring stem cells and proteins inside the shape of the implant, which would eventually dissolve away as it is replaced by bone.
The technology is of particular interest to the U.S. military which would use bone re-growth implants for battlefield injuries.
“Our vision is it will be available for soldiers at (Army medical post) Landstuhl, Water Reed, or Brooke Army Medical center,” she said.
The two-year project has already had $3 million behind it from the Navy, National Institute of Health and, most recently, the U.S. Army’s Medical Research and Materiel Command.
The project is managed out of the Tucson office, but also involves the University of Texas at San Antonio and Carnegie Mellon University.
Testing is being done on rabbits by drilling a tiny hole in the top of the femur so a cylindrical piece of Plasti-Bone can be inserted to see if tissue will fill in the gaps. Tellis said this stage is important because the material must be successful in animal trials before proceeding to human trials, something she expects to see in three to five years.
“Going with material that the FDA is already happy with made it much easier,” Tellis said.
If there is a local researcher under the age of 35 you think should be featured in a future column, contact Nicholas Smith at nsmith@azbiz.com or at (520) 295-4238. The Next Generation appears in the first week of each month in Inside Tucson Business.
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