Engineers have designed a microfluidics and nano-scale diagnostic toolkit suitable for attaching directly to muscle and tissue to monitor biomarkers and stream results wirelessly to care providers and medical laboratories

What would change in medicine if physicians had sutures that could collect and report biomarker data, including the kinds of biomarkers that are used in clinical laboratory tests? Such a product may be feasible, based on newly-published research.

“Smart sutures” are a joint project between Tufts University, Harvard University, and Massachusetts Institute of Technology (MIT) engineers. They announced a thread-based diagnostic device (TDD) system capable of detecting biomarkers and analytes using 3D sutures composed of cotton and synthetic threads.

Processing the cotton and synthetic threads in various ways enhances their natural properties. The toolkit of different sutures developed by the team has exhibited a range of uses—including measuring physical stress at an incision, monitoring pH of tissues and fluids, and measuring glucose.

Published July 2016 in Nature.com Microsystems & Nanoengineering, the team’s latest study into the technology appears promising. Of interest to pathology groups and clinical laboratories is the ability for the toolkit to penetrate and monitor through multiple layers of tissue or muscle. This makes it possible to analyze interstitial fluids for biomarkers or analytes in areas where previous rigid, planar technologies might not work.

Thread-based Diagnostic Devices Enable Implementation of In Vivo Diagnostics

In a Tufts University news release, corresponding author on the study Sameer Sonkusale, PhD, stated, “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.”

He highlighted the importance that thread-based devices might hold in building a new generation of integrated health monitoring and point-of-care testing (POCT) devices, as the materials and techniques are more accessible and cost effective than many synthetic applications and technologies in use today.

A toolkit of thread-based chemical and physical sensors, microfluidic channels, and interconnects for the realization of a thread-based diagnostic device (TDD), shown here for transdermal health monitoring. (Image and caption copyright: Nature.com.)

A toolkit of thread-based chemical and physical sensors, microfluidic channels, and interconnects for the realization of a thread-based diagnostic device (TDD), shown here for transdermal health monitoring. (Image and caption copyright: Nature.com.)

According to the study, thread-based diagnostic devices offer greater flexibility than both nanofibrous polymeric substrates and paper-based platforms, while also improving resilience in vivo. “Although these substrates hold great promise for the creation of wearable and implantable devices, their overall structure and form has essentially remained two-dimensional, limiting their function to tissue surfaces, such as skin,” the study notes. “However, the ability to integrate functional components, such as sensors, actuators, and electronics, in a way that they can penetrate multiple layers of tissues in a 3D topology would be a significant advance.”

Powering the Future of Translational and Precision Medicine Using Thread

The study authors hope that innovative technology such as this will form the foundation for new ways to design and implement diagnostic tests. They note, “We envision being able to extend the approach to more than the strain, pH, or glucose sensors mentioned here by functionalizing them with sensing chemistries to measure proteins, DNA, and other biomarkers directly in the tissues where they are implanted.”

Pathology groups already play a leading role in both managing the data behind precision medicine and helping to discover new biomarkers to power data collection and analysis. Affordable, accessible technologies, such as these proposed TDDs, offer the potential to greatly accelerate the rate at which precision medicine grows.

Thread-based diagnostic devices are designed to connect wirelessly with smartphones and medical laboratory equipment using common electronic components. Future devices might offer direct integration with laboratory information systems (LISs), electronic health records (EHRs), and other data management and analytics systems, further reducing the time required to go from detection and analysis to decision and care.

Challenges in Implementing TDDs

Still in the early stages of design and testing, the study notes two major obstacles standing in the way of TDDs. The first is proof of long-term biocompatibility. Current in vivo testing is limited to rats and short-term exposure. However, the authors feel that prior research related to the design on both the materials used within systems, as well as the treatments used to achieve the desired result within thread components, ensures that biocompatibility potential remains high.

The second challenge facing researchers is integration of additional electronic components to further improve the capabilities of their toolkits. Study authors note, “Although we demonstrated thread-based interconnects, future efforts could be in the area of integrating other electronic components, such as capacitors, diodes, and transistors, on threads, which will result in a truly self-contained integrated platform with unmatched size, flexibility, and maneuverability.”

While the past five years have seen a regular stream of new devices promising to revolutionize testing and monitoring, few have yet to achieve market approval or widespread use. Though the fate of thread-based diagnostic devices is unsure, they are an example of how even basic materials looked at in a new way can offer great value to medical laboratories, offer new methods for collecting data, and further the development of precision medicine.

—Jon Stone

Related Information:

Novel 3D “Smart” Sutures for Wireless Collection of Biological 

A Toolkit of Thread-Based Microfluidics, Sensors, and Electronics for 3D Tissue Embedding for Medical Diagnostics

Smart Stitches Send Data as They Heal Wounds

Smart Sutures May Tell Post-Op Patients How They’re Doing

Researchers Invent “Smart” Thread that Collects Diagnostic Data when Sutured into Tissue