Tiny Electronic Devices Travel with Immune Cells to Target Inflammation

A team of researchers at the Massachusetts Institute of Technology (MIT) has developed a groundbreaking method to deliver microscopic electronic devices to sites of inflammation in the brain. Led by electrical engineer Deblina Sarkar, the innovative approach employs living immune cells to transport the devices through the bloodstream, potentially revolutionizing treatment for various neurological conditions.

Traditional brain implants rely on surgical procedures to place electrodes within the brain’s gray matter. This new technology, which Sarkar refers to as “circulatronics,” circumvents the need for invasive surgery by using monocytes—immune cells capable of navigating the bloodstream and targeting areas of inflammation. This strategy addresses several significant challenges that have hindered previous attempts at creating similar technologies.

In 2022, after years of setbacks, Sarkar’s team received the National Institutes of Health Director’s New Innovator Award, marking a pivotal moment in their research journey. “We received the highest impact score ever,” Sarkar noted, emphasizing the project’s potential. The team’s work focused on creating functional electronic devices that are smaller than human cells, allowing them to circulate within the blood.

One of the primary hurdles faced by researchers was the creation of electronic devices that could bypass the blood-brain barrier, a protective mechanism that restricts the entry of harmful substances into the brain. Previous efforts to utilize magnetic particles for this purpose failed because they could not effectively navigate the complex pathways of the human body. Sarkar’s team shifted their focus to fusing electronic devices with monocytes, which are naturally equipped to home in on areas of inflammation.

Sarkar’s team crafted biocompatible electronic devices using a standard complementary metal-oxide-semiconductor (CMOS) process, resulting in devices that are approximately 200 nanometers thick and 10 microns in diameter. The devices are powered and activated by infrared light, a feature that allows them to effectively stimulate neuronal activity once implanted.

To attach the devices to monocytes, the researchers employed a method known as click chemistry, a process that facilitates rapid bonding between the electronic components and the immune cells. “This approach allows us to create cell-electronics hybrids that can be injected into the body,” Sarkar explained. These hybrids could then target specific areas in the brain, marking a significant leap forward in the field of neurotechnology.

In experimental trials, the team tested the hybrids on mice by artificially inducing inflammation in a specific brain region. Following injection, the researchers found that around 14,000 hybrids effectively localized to the target area within 72 hours, demonstrating the technology’s potential to replicate the effects of traditional surgical electrodes.

Sarkar underscored the adaptability of the hybrids, noting that they can be tailored for various medical applications. “We have tested using mesenchymal stem cells for Alzheimer’s and T cells for tumors,” she said. This versatility opens up new possibilities for targeting diseases that currently have limited treatment options.

The research holds promise for conditions such as glioblastoma, an aggressive brain cancer characterized by diffuse tumor sites, and DIPG, a terminal brain cancer in children where surgical intervention is often not feasible. Sarkar envisions that the ability to deliver these implants safely could lead to breakthroughs in treating otherwise inaccessible brain regions.

Looking ahead, the team plans to conduct trials on larger animals before seeking approval from the U.S. Food and Drug Administration for clinical use. Through Cahira Technologies, a company formed to commercialize the circulatronics technology, Sarkar aims to bring this innovative approach to market within the next three years.

The implications of this research extend beyond therapeutic applications. Sarkar believes that the technology may enable researchers to collect brain data from healthy individuals, paving the way for advancements in brain-computer interfaces. As the team continues to refine their methods, the potential for enhancing human cognition through artificial neurons becomes increasingly tangible, representing a significant step forward in the field of neurotechnology.