Back to nature: Guo wins DARPA Young Faculty Award for next-gen neural implant technology
Liang Guo finally took a step back and saw a new vision.While working many years on building electronic neural implants for disease treatment at The Ohio State University, Electrical and Computer Engineering (ECE) Assistant Professor
Why are they trying to force the body to accept electronic implants it is not naturally designed to cope with? Research shows it is not a long-term solution. Instead, why not employ living cells performing their natural functions and get better results?
Imagine implanting a cardiac pacemaker, grown from the patient's own cells, back inside the body where it can assist the diseased organ. Moreso, it is powered simply by the natural flow of blood.
This realization made Guo rethink his entire philosophy regarding implantable medical electronics, to the point of veering his research into the new realms of biocircuit engineering to create autologous medical devices.
Guo believes this is the hope of new implantable technology. The question now is, where do they start?
“The best way is to learn from nature,” he said. “In this process, we can learn how the neurobiological circuits are designed from living cells. Once we learn enough, we may be able to expand to artificial designs on those biological principles. That’s my whole philosophy.”
The Defense Advanced Research Projects Agency (DARPA) sees the potential. Guo just received $499,999 in funding over the next two years by winning the prestigious DARPA Young Faculty Award for his proposal, “Implantable, Programmable Integrated Cellular Circuits.”
Guo has a joint faculty appointment between ECE and Neuroscience. The Neuroscience Research Institute at Ohio State provides its Neuromodulation Lab space for his work in the Biomedical Research Tower to facilitate novel and important innovations in neuromodulation at the university.
With the funding in place, he is visibly excited to begin.
“I was so surprised,” Guo said about being selected by DARPA. “We feel so lucky it got funded.”
When it comes to looking to nature for simple neurobiological circuits to initiate this engineering endeavor, Guo decided to follow the well-established lead of Columbia University Professor Eric Kandel, who won the 2000 Nobel Prize for his research on the physiological basis of memory storage in the simple neurobiological circuits of the Aplysia californica (also known as the California sea slug or sea hare).
Ohio State ECE Department Chair and Professor, Joel Johnson, said the DARPA Young Faculty Award is a significant achievement for a junior faculty member of the department.
“It’s really going to stimulate our work in the medical cellular circuits area for neural implants,” Johnson said. “This is an exciting area of research. There are a lot of innovations happening in this field at the current time, and the new collaborations we will be building with the Ohio State College of Medicine will lead to even greater research in medical applications in the future.”
Guo said the plan now is to forward engineer the classic gill-withdrawal reflex circuit inside the Aplysia from bottom up to recapitulate its natural functions.
“We understand this circuit very well. Cell by cell," he said "My goal is, can we isolate those cells and reconstruct the circuit in a culture dish? Furthermore, can we re-implant the constructed circuit back into the animal to see if it can substitute?”
Guo said using neurons to engineer neurobiological circuits is not a new idea or concept.
“It has been a few decades that people have been trying to use neurons to engineer artificially designed circuits and devices, but most of the approaches either lack sufficient controls over the design or are trying to manipulate cells to do something they were not designed to do,” he said. “My idea and research concept is we should use these cells in the way they are designed by nature. We should first replicate their innate circuits, as faithful as possible.”
Guo said they are on the ground floor of this research, but it shows potential to engineer tissue-like medical devices to eventually assist diseased or malfunctioning organs in the body.
“Once we master the skills and knowledge to engineer these innate cellular circuits. We can expand our capability to advance these, involving more cells and more artificial designs,” Guo said. “The best way to start is to try and mimic what is already there. It is guaranteed that these cells are designed for these circuits. How can we make that happen? That’s what we want to pursue in this project.”
He feels this is why DARPA is supporting the research. The goals of this project are logically more feasible.
“We just need to learn how to make it happen,” Guo said. “The funding is going to push this ambition.”
Currently, he said, neural prosthetic implants are already capable of changing behaviors in humans, or suppressing abnormal brain activities to help control Parkinson’s disease and epilepsy. However, existing technology is far from sufficient as a lifetime solution.
“I used to work on the implantable neuroelectronics. We built stretchable neural sensor arrays and we wanted to implant those sensors in the nervous system of the patient. But the foreign implant does not work well with the tissue. The body will not accept it well because it is made of alien materials and functions differently from the biological systems,” Guo said. “Since we want these electronic circuits to be integrated with the neural tissue, both physically and functionally, why don’t we directly use the patient’s own cells to engineer these circuit functionalities, instead? So, that’s how I came up from the traditional neuroelectronics research to this new line of biocircuit engineering.”
Guo is working on the research with doctoral students, Yu Wu in ECE and Jordan Prox in Biomedical Sciences Graduate Program, out of the Biomedical Research Tower at Ohio State.
“This is very promising,” Wu said about their work. “Aplysia is a very simple animal. It has already been used in textbooks. It has been very extensively studied. Technically, we can overcome many barriers to directly pursue our goal to program the neural circuits to do what we want.”
With a background primarily in biochemistry and molecular biology, Prox was attracted to neural engineering because of its emerging technical potential. He sought out Guo for more expertise.
“He is one of the very few neuro-engineers here right now,” Prox said. “It’s a more simplistic approach compared to our previous projects, taking a design that has already been used and trying to modify it and add different approaches for being able to modulate different behaviors.”