We need technologies that will allow our bodies to be repaired as thoroughly as we repair our cars. Some UCSD researchers find that titanium nanotubes can cause stem cells to become osteoblasts that speed bone repair.
San Diego, CA, January 29, 2009 --Engineers at the University of California at San Diego have come up with a way to help accelerate bone growth through the use of nanotubes and stem cells. This new finding could lead to quicker and better recovery, for example, for patients who undergo orthopedic surgery.
Nanotube implants might some day become a routine part of orthopedic surgery.
“If you break your knee or leg from skiing, for example, an orthopedic surgeon will implant a titanium rod, and you will be on crutches for about three months,” said Sungho Jin, co-author of the PNAS paper and a materials science professor at the Jacobs School of Engineering. “But what we anticipate through our research is that if the surgeon uses titanium oxide nanotubes with stem cells, the bone healing could be accelerated and a patient may be able to walk in one month instead of being on crunches for three months.
“Our in-vitro and in-vivo data indicate that such advantages can occur by using the titanium oxide nanotube treated implants, which can reduce the loosening of bones, one of the major orthopedic problems that necessitate re-surgery operations for hip and other implants for patients,” Jin added. “Such a major re-surgery, especially for older people, is a health risk and significant inconvenience, and is also undesirable from the cost point of view.”
By controlling nanotube diameter the researchers can instruct stem cells to turn into bone-forming osteoblast cells.
This is the first study of its kind using stem cells attached to titanium oxide nanotube implants. Jin and his research team – which include Jacobs School bioengineering professors Shu Chien and Adam Engler, as well as post doctoral researcher Seunghan Oh and other graduate students and researchers –report that the precise change in nanotube diameter can be controlled to induce selective differentiation of stem cells into osteoblast (bone-forming) cells.
The biggest challenge with stem cells is instructing them to become the right kind of cell at the right place in the body. A material implanted where the repair is needed has the advantage of being very local in its effects. That can work for highly targeted repairs where a particular piece of tissue needs fixing.
We also need ways to instruct stem cells to go to particular types of tissue that might be scattered all around the body. For example, bone marrow stem cells age along with the rest of the body. Well, we have about 206 bones per person (I say "about" because there is some variation - for example, some people have an extra rib). That's a lot of places to instruct stem cells to go to and replace aged stem cells. We will need additional techniques for more widespread stem cell delivery.
|Share |||Randall Parker, 2009 February 01 04:52 PM Nanotech for Biotech|