Scientists at the Massachusetts Institute of Technology have developed an intelligent bandage, which can monitor the patient’s condition and deliver medication when it senses that the patient is in pain.
The “smart wound dressing” contains temperature sensors, LED lights, and other electronics, as well as tiny reservoirs of prescribed medication. Right now it’s intended for use on the skin, but someday soon it may be used to repair problems deep within the “bowl of jello” that is the human brain.
The dressing is a new kind of hydrogel. A hydrogel is a rubbery material, mostly composed of water, initially designed to bond strongly to porous surfaces such as gold, titanium, aluminum, silicon, glass, and ceramic. Typically, hydrogels are brittle, barely stretchable, and adhere weakly to other surfaces. They tend to degrade over time too.
The key to the smart wound dressing design is a new hydrogel matrix designed by Xuanhe Zhao, Associate Professor in MIT’s Department of Mechanical Engineering.
By adding selected biopolymers to the water, Xuanhe Zhao and his team developed a hydrogel that was stretchy and could be attached to non-porous materials. Their hydrogel mimics some of the features of human soft tissues, and does not degrade nearly as rapidly as other hydrogels.
When applied to a highly flexible area, such as the elbow or knee, it stretches with the body, keeping the embedded electronics functional and intact. It’s also tenacious, the dressing sticks to surfaces with more than the strength of the natural adhesives used by barnacles to attach themselves to ship hulls.
The MIT research team that designed the initial hydrogel also developed the wound dressing. Along with embedding temperature sensors and drug reservoirs they also created pathways for drugs to flow through the hydrogel, by inserting patterned tubes and drilling tiny holes through the matrix. Medications can be delivered to a specific location in the wound, and although the reservoirs can contain multiple meds the bandage can determine (or be directed) to release a specific medication in response to the patient’s vital signs.
The researchers think that the technology may work especially well to provide on-demand treatment for burns or other skin conditions. They are testing the possibility of embedding glucose sensors into the hydrogel, which would monitor blood sugar levels and deliver diabetic medications.
They also believe that their work may allow electronics to be safely used inside the body and eventually could be used to implant neural devices in the brain due to the similarities between the hydrogel and brain tissue.
“The brain is a bowl of Jell-O,” Zhao says. “Currently, researchers are trying different soft materials to achieve long-term biocompatibility of neural devices. With collaborators, we are proposing to use robust hydrogel as an ideal material for neural devices, because the hydrogel can be designed to possess similar mechanical and physiological properties as the brain.”
This research was funded, in part, by the Office of Naval Research, the MIT Institute for Soldier Nanotechnologies, and the National Science Foundation.