Imagine having tiny devices implanted in your nervous system, tracking brain signals to detect and treat a range of chronic diseases. That’s the aim of bio-electronic medicine — a rapidly advancing field in which Prof. Shimon Weiss is involved. A veteran biomedical entrepreneur recruited recently by BINA, Weiss heads the laboratory for Nano-Sensors in Brain Research, and is also a faculty member at UCLA.
Deciphering electrical body language.
“We use voltage-sensing nanorods that can self-insert into live neurons in the nervous system. These nanorods can optically sense electrical signals, and thereby detect neuronal activity,” explained Prof. Weiss. “Combining this technology with a highly-sensitive camera will enable us to read electronic brain signals in real time, and, in the future, to explore emergent properties of a large neural network of live, behaving animals”, he said.
For nearly 3 decades, Weiss has played a pioneering role in researching and inventing technologies in the fields of nanotechnology, single molecule biophysics, super-resolution imaging, and their applications in biology and biomedicine.
Weiss predicts that in the future such devices will be programmed to modify irregular electrical signals in the body that are associated with a range of diseases. “By injecting corrective signals into specific groups of neurons, we will be able to repair malfunctioning neurological circuits, and, hopefully, help treat chronic diseases with greater precision and fewer side effects than with conventional medicine. Our research opens up vast opportunities for biomedicine, and possibly for other applications such as artificial light-harvesting as an alternative source of renewable energy,” he points out.
A former IDF combat pilot, Weiss attained his PHD in electrical engineering from the Technion, and in 1989 moved to New Jersey for a post-doctoral position at AT&T Bell Labs. A year later he joined the Lawrence Berkeley National Laboratory as a staff scientist, and in 1998 he co-founded the Quantum Dot Corporation - the first to use fluorescent QDs as biological probes. In 2001 he moved to UCLA and began testing QDs for super-resolution imaging, which eventually, opened new horizons in biology.
Milestones and quantum leaps
“In 1993, we had just constructed a near-field scanning optical microscope (NSOM) which I was eager to start using” Weiss reminisces. “We placed fluorescent dye molecules on a cover slip under the microscope, and were able to see individual molecules. We then placed another acceptor molecule next to the first donor molecule. Not only could we now view individual florescent molecules at room temperature, but we were also able to measure energy transferring directly from a single donor molecule to a single acceptor molecule via smFRET (single molecule fluorescence resonance energy transfer)”, exclaimed Weiss.
“The implications were ground-breaking: for the first time ever, we were watching biological macromolecules in motion, in real time. Essentially, we had transformed static structural biology into dynamic structural biology. Our methodology was adopted later by scientists and utilized in numerous biomedical applications.”
Another defining moment in Weiss’s career occurred during a lecture by Paul Alivisatos – an American scientist and pioneer in nanomaterials. “A slide showing QDs sparked my idea: If certain colours of QDs could possibly be excited by a single laser line, then perhaps we could use specific colours to mark proteins, and track their movement inside a living cell – utilizing simple optics”, said Weiss.
The idea led to the establishment of the Quantum Dot Corporation by Weiss and Alivisatos. QDs have since become a key reagent for modern cellular imaging, small animal imaging, bio-detection, and diagnostic analysis.
Today, Weiss divides his time between Bar Ilan University and UCLA where he teaches chemistry and biochemistry. “I predict that imaging technologies based on single molecule spectroscopy will help solve life-threatening conditions; produce better drugs; enable earlier diagnosis and more effective in-vitro fertilization; and enhance personalized medicine – developments which are all likely to use some form of single-molecule detection technology.”
Originally published in Institute for Nanotechnology and Advanced Materials' April 2017 newsletter