In new study published in Nature Biotechnology titled, “A non-surgical brain implant enabled through cell-electronics hybrid for focal neuromodulation,” researchers from Massachusetts Institute of Technology (MIT) have developed microscopic, wireless bioelectronics that can autonomously self-implant in a target region of the brain to provide neuromodulation, providing an avenue to treat brain tumors and diseases, such as Alzheimer’s and multiple sclerosis.
“While brain implants usually require hundreds of thousands of dollars in medical costs and risky surgical procedures, circulatronics technology holds the potential to make therapeutic brain implants accessible to all by eliminating the need for surgery,” said Deblina Sarkar, PhD, associate professor at the MIT Center for Neurobiological Engineering, head of the Nano-Cybernetic Biotrek Lab, and corresponding author of the study.
Demonstrated in a study in mice, these miniscule implants identify and travel to a specific brain region without the need for human guidance after injection. They are then wirelessly powered to provide electrical stimulation to the precise area for neuromodulation. As the implants are integrated with living, biological cells before injection, they avoid rejection by the body’s immune system and can cross the blood-brain barrier.
The researchers demonstrated the use of this technology to target brain inflammation, a major factor in the progression of many neurological diseases. The implants can provide high precision localized neuromodulation within several microns around the target area.
The electronic devices, each about one-billionth the length of a grain of rice, are composed of organic semiconducting polymer layers sandwiched between metallic layers to create an electronic heterostructure. Through a series of biocompatibility tests, the researchers found that the small implants can safely integrate among neurons without impacting the brain processes behind cognition or motion.
The authors use a chemical reaction to fuse the electronics with a type of immune cell called monocytes, which target areas of inflammation in the body. A fluorescent dye traced the devices as they crossed the intact blood-brain barrier and self-implanted in the target brain region.
“Our cell-electronics hybrid fuses the versatility of electronics with the biological transport and biochemical sensing prowess of living cells,” Sarkar says. “The living cells camouflage the electronics so that they aren’t attacked by the body’s immune system and they can travel seamlessly through the bloodstream. This also enables them to squeeze through the intact blood-brain barrier without the need to invasively open it.”
The small size and self-implantation capabilities make these implants potentially well-suited to treat brain cancers such as glioblastoma that cause tumors at multiple locations, which may be too small to identify with imaging techniques, and diffuse intrinsic pontine glioma, an aggressive type of tumor found in the brain stem that usually cannot be surgically removed.
“This is a platform technology and may be employed to treat multiple brain diseases and mental illnesses,” Sarkar says. “Also, this technology is not just confined to the brain but could also be extended to other parts of the body in future.”
The researchers hope to move the technology into clinical trials within three years through the recently launched startup Cahira Technologies. They are also exploring integration of additional nanoelectronic circuits into the devices to enable functionalities including sensing, feedback based on-chip data analysis, and capabilities such as creating synthetic electronic neurons.
“Our tiny electronic devices seamlessly integrate with the neurons and co-live and co-exist with the brain cells creating a unique brain-computer symbiosis. We are working dedicatedly to employ this technology for treating neural diseases, where drugs or standard therapies fail, for alleviating human suffering and envision a future where humans could transcend beyond diseases and biological limitations,” says Sarkar.
