New 'smart' thread may help monitor stitched tissues

For the first time, scientists, including one of Indian-origin, have developed smart threads integrated with nano-scale sensors, electronics and microfluidics that can be stitched through layers of tissue to gather diagnostic data in real time.
The research led by Tufts University in the US suggests that the thread-based diagnostic platform could be an effective substrate for a new generation of implantable diagnostic devices and smart wearable systems.
The researchers used a variety of conductive threads that were dipped in physical and chemical sensing compounds and connected to wireless electronic circuitry to create a flexible platform that they sutured into tissue in rats as well as in vitro.

The threads collected data on tissue health, pH and glucose levels that can be used to determine such things as how a wound is healing, whether infection is emerging, or whether the body's chemistry is out of balance.
The results were transmitted wirelessly to a cell phone and computer.
The 3D platform is able to conform to complex structures such as organs, wounds or orthopedic implants.

While more study is needed in a number of areas, researchers said initial results raise the possibility of optimising patient-specific treatments.
"The ability to suture a thread-based diagnostic device intimately in a tissue or organ environment in three dimensions adds a unique feature that is not available with other flexible diagnostic platforms," said Sameer Sonkusale, from Tufts University's School of Engineering.

"We think thread-based devices could potentially be used as smart sutures for surgical implants, smart bandages to monitor wound healing, or integrated with textile or fabric as personalised health monitors and point-of-care diagnostics," Sonkusale said.
Until now, the structure of substrates for implantable devices has essentially been two-dimensional, limiting their usefulness to flat tissue such as skin.
The materials in those substrates are expensive and require specialised processing, researchers said.
"By contrast, thread is abundant, inexpensive, thin and flexible, and can be easily manipulated into complex shapes," said Pooria Mostafalu, who was a doctoral student at Tufts when he worked on the project.

"Additionally, analytes can be delivered directly to tissue by using thread's natural wicking properties," Mostafalu said.
The study was published in the journal Microsystems and Nanoengineering.