A new study entitled “Syringe-injectable electronics” recently published in the journal Nature Nanotechnology revealed an innovative method to employ tiny electronic devices in the brain, or other parts of the body, as a potential therapy for a wide range of disorders, including neurodegenerative diseases like amyotrophic lateral sclerosis (ALS). The study was performed by researchers at the Harvard University in Cambridge, Massachusetts and the National Center for Nanoscience and Technology in China.
ALS is a progressive neurodegenerative disease characterized by the gradual degeneration and atrophy of motor neurons in the brain and spinal cord that are responsible for controlling essential voluntary muscles, such as the ones related to movement, speaking, eating, and even breathing. It is estimated that more than 300,000 Americans suffer from this disease.
The team had previously shown that cardiac or nerve cells grown with embedded nano-scale electronic scaffolds could generate a so-called “cyborg” tissue. The electronic devices could then record the electrical signals generated by the tissues, and measure signal changes when cardio- or neuro-stimulating drugs were administered to the cells.
Minimally invasive targeted delivery of electronics into artificial or natural structures is however a challenge. “We were able to demonstrate that we could make this scaffold and culture cells within it, but we didn’t really have an idea how to insert that into pre-existing tissue,” explained the study’s senior author Dr. Charles Lieber in a news release. Now, Dr. Lieber and colleagues have developed a pioneering method where sub-micrometer-thick mesh electronics can be delivered to their target through injection via a syringe.
“When releasing the electronics scaffold completely from the fabrication substrate, we noticed that it was almost invisible and very flexible like a polymer and could literally be sucked into a glass needle or pipette. From there, we simply asked, would it be possible to deliver the mesh electronics by syringe needle injection, a process common to delivery of many species in biology and medicine — you could go to the doctor and you inject this and you’re wired up.” said Dr. Lieber.
Current devices based on silicon probes or flexible polymers “cause inflammation in the tissue that requires periodically changing the position or the stimulation. But with our injectable electronics, it’s as if it’s not there at all. They are one million times more flexible than any state-of-the-art flexible electronics and have subcellular feature sizes. They’re what I call “neuro-philic” — they actually like to interact with neurons.” explained Dr. Lieber.
According to the team, the creation of the injectable scaffold is relatively easy. Researchers lay out a mesh of nanowires sandwiched in layers of organic polymer, then the first layer is dissolved creating the flexible mesh, which can be administered through a syringe needle like any other injection. After injection, the mesh can be connected to standard electronic devices to monitor neural activity, stimulate tissues and even promote regeneration of neurons.
“These type of things have never been done before, from both a fundamental neuroscience and medical perspective,” noted Dr. Lieber. “It’s really exciting — there are a lot of potential applications. (…) The idea of being able to precisely position and record from very specific areas, or even from specific neurons over an extended period of time — this could, I think, make a huge impact on neuroscience.” The team hopes to discover new insights into how the brain and other tissues respond to the injectable electronics over longer periods.
“I do feel that this has the potential to be revolutionary,” concluded Dr. Lieber. “This opens up a completely new frontier where we can explore the interface between electronic structures and biology.”
Harvard’s Office of Technology Development has filed for a provisional patent on this technology and is actively pursuing commercialization opportunities.