Nanotech Sensors Keep a Close Eye on Orthopedic Implants

When it comes to nanotech sensors for monitoring health, Northeastern University (Boston) professor Thomas J. Webster, PhD wrote the book. Literally.

Webster spoke on advances in this domain at the BIOMEDevice Boston conference. An example of a breakthrough that was covered in his talk is the development of an implantable nanosensor that can measure cellular function. While the applications for this technology are numerous, orthopedics is among the first Webster's research team is targeting. The device can be bundled with, say, a spinal implant or a hip implant to help repair damaged bone. "As soon as the implant is inserted in the body, the sensor can determine if a bone cell attached to the implant, which would be great," Webster explains. "It can also measure if a bacteria attached to it--you don't want that. Or it can tell if an inflammatory cell attached--a cell from our immune system that would create scar tissue to grow rather than healthy tissue. You obviously don't want that either," he adds.

The technology is able to discern which kinds of cells attach to implants by measuring their conductivity. "Each one of those cells, a bone cell, a bacteria, an inflammatory cell has different conductivity--as do all cells in the body," Webster says.

Using radiofrequency communication, the sensor can communicate how well an implant is faring in the body to a handheld device. The program within the handheld device would interpret that signal and provide feedback to the patient. A patient, for instance, might be informed that the bone growth surrounding the implant is healthy. Or, if bacteria is growing on the implant--or inflammation is setting in, the patient could be instructed to make an appointment with their orthopedic surgeon. Alternately, upon detecting bacterial growth or inflammation, the device could trigger the release of either an antibiotic or an antiinflammatory agent. (For more on how that works, see the diagram above). "Then it can continue like that.  It can determine did that antibiotic drug really work? Or are bacteria still growing? Or conversely, has bone started to grow in the place where the bacteria once were?" Webster asks. "You get this basic feedback loop on top of the orthopedic implant."

The technology could be used for a variety of other applications as well, ranging from stents to infection-detecting polymers for other types of implants.

More content on Webster's research:

Brian Buntz is the editor-in-chief of MPMN. Follow him on Twitter at @brian_buntz.