Wireless drug delivery to the brain achieved in mice using a smartphone

Written by Sharon Salt, Editor

Researchers from South Korea and the USA have created a device that is able to manipulate neural circuits via a small brain implant controlled by a smartphone.  
The research, which has been published in Nature Biomedical Engineeringutilizes a Lego-like replaceable drug cartridge and powerful Bluetooth low-energy to target specific neurons of interest using drug and light for prolonged periods.  

This is an image of a wireless neural device on a mouse brain that uses Lego-like replaceable drug cartridges to target specific neurons using drug and light for prolonged periods.

Image credit: KAIST

According to lead author Raza Qazi (Korea Advanced Institute of Science and Technology [KAIST], Daejeon, South Korea), this new technology significantly overshadows current methods used by researchers. To deliver drugs and light, conventional methods typically involve rigid metal tubes and optical fibers. Not only does this limit movement from the subject due to bulky equipment but also, their relatively rigid structures have been reported to cause lesions in soft brain tissue over time.

Although efforts have been made to overcome the challenges associated with conventional methods (e.g., by incorporating soft probes and wireless platforms), they have been limited by their inability to maintain long-term drug delivery in addition to their complex setup.  

Thus, to achieve a chronic wireless drug-delivery system, researchers in the present study invented a neural device with a replaceable drug cartridge. These cartridges were assembled into a brain implant for mice, which included an ultrathin probe (thickness of a human hair) that consisted of microfluidic channels and tiny LEDs (smaller than a grain of salt), for unlimited drug doses and light delivery.  

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The system could then be controlled via a simple smartphone interface that allowed scientists to easily trigger specific combinations and/or precise light sequencing in an implanted animal without the need to physically be in the laboratory.  

One example whereby the team utilized this wireless system included behavior studies. The investigators reported that the behavior of one animal could either positively or negatively affect the behavior in other animals by the conditional triggering of light and/or drug delivery.  

“This revolutionary device is the fruit of advanced electronics design and powerful micro and nanoscale engineering. We are interested in further developing this technology to make a brain implant for clinical applications,” explained co-author Jae-Woong Jeong (KAIST).  

To conclude, Michael Bruchas (University of Washington School of Medicine) stated: “It allows us to better dissect the neural circuit basis of behavior, and how specific neuromodulators in the brain tune behavior in various ways. We are also eager to use this device for complex pharmacological studies, which could help us develop new therapeutics for pain, addiction and emotional disorders.”   

Sources: Qazi R, Gomez AM, Castro DC et al. Wireless optofluidic brain probes for chronic neuropharmacology and photostimulationNat. Biomed. Engineering doi:10.1038/s41551-019-0432-1 (2019) (Epub ahead of print); https://newsroom.uw.edu/news/scientists-manipulate-brain-cells-using-smartphone