Smart thread collects data from patient tissue

Published in the journal Microsystems & Nanoengineering, the research details how the team experimented with various types of thread, ranging from simple cotton to complex synthetics. Incorporating nano-scale sensors, electronics and microfluidics, the thread can be sutured through multiple layers of tissue. The physical and chemical sensors collect data measuring pressure, stress, strain and temperature, as well as pH and glucose levels. This data can indicate whether a wound is healing correctly or if an infection is setting in.

"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 Dr Sameer Sonkusale from Tuft’s Department of Electrical and Computer Engineering, one of the paper’s authors.

"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."

According to the researchers, the threads were first dipped in physical and chemical sensing compounds, then connected to wireless electronic circuitry. The Tufts engineers believe nature of thread is a step forward from traditional 2D implantable substrates, which have been limited to collecting data from flat surfaces such as skin. But the smart thread can collect data from across a wider, 3D area, and can conform to complex structures such as organs, wounds or orthopaedic implants.

“Thread is abundant, inexpensive, thin and flexible, and can be easily manipulated into complex shapes," said Dr Pooria Mostafalu, a former doctoral student at Tufts now working at Harvard, and the paper’s first author. "Additionally, analytes can be delivered directly to tissue by using thread's natural wicking properties."

While the long-term biocompatibility of the thread still needs to be investigated, the team are hopeful that the technology can be commercialised, and will one day lead to patient-specific treatments.