BME Researchers Serve on Team That Publishes Pioneering Paper in Nature Communications

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Dmitry Kireev

Assistant Professor Dmitry Kireev and his Postdoctoral Research Associate Prashant Narute of the UMass Amherst Biomedical Engineering (BME) Department are members of a 20-person research team that recently published a cutting-edge paper in the prestigious journal Nature Communications. The paper reports on trailblazing research that introduces a platform that leverages graphene’s ability to convert light into electricity and thereby enhances our ability to modulate neural activity at will, which is essential for many kinds of fundamental research and therapeutic applications. Kireev and Narute played a fundamental role in the research at the device and material-characterization level. See Non-genetic neuromodulation with graphene optoelectronic.

The paper – “Non-genetic neuromodulation with graphene optoelectronic actuators for disease models, stem-cell maturation, and biohybrid robotics” – was a collaborative effort by researchers from UMass Amherst and seven international institutions, mainly led by the University of California at San Diego (UCSD) and the Nanotools Bioscience company of La Jolla, California. The three corresponding authors of the paper were Elena Molokanova and Alex Savchenko of Nanotools Bioscience and Alysson R. Muotri of UCSD.

The backdrop of this project is that the ability to modulate neural activity at will is essential for fundamental research and therapeutic applications, including understanding brain function, disease modeling, neuro-engineering, and developmental and regenerative neuroscience. Light is an exceptional actuating stimulus for neuromodulation due to its high spatial and temporal precision, non-invasiveness, tunability, and compatibility with various techniques for monitoring neural activity. 

The problem is that neurons are not inherently light-sensitive and therefore cannot respond to light on their own. To be modulated by light, neurons must either be genetically or structurally modified with internally inserted light-sensitive modules or integrated with external optical actuators.

The Nature Communications paper reports on a viable answer to this problem using optoelectronic actuators. “Here,” says the research team, “we introduce the Graphene-Mediated Optical Stimulation (GraMOS) platform, which leverages graphene’s optoelectronic properties and its ability to efficiently convert light into electricity. Using GraMOS in longitudinal studies, we found that repeated optical stimulation enhances the maturation of ‘human-induced pluripotent [capable of developing into many different cell types] stem-cell-derived neurons’ and brain organoids, underscoring GraMOS’s potential for regenerative medicine and neurodevelopmental studies.”

Brain organoids are artificially grown, three-dimensional models of brain tissue derived from human pluripotent stem cells and used to study brain development and neurological diseases. 

As Kireev and Narute explain about their work on the research team, “In this project, we played a fundamental role at the device and material-characterization level. We analyzed the newly synthesized graphene (reduced graphene oxide, rGO) to explore its structure and property relationships, examining its optical and electrical behavior using advanced characterization techniques.” 

In addition, as Kireev and Narute say, “We measured GraMOS’s optoelectronic properties; that is, how its electrical response changes when exposed to light. To do this, we shined ultraviolet light on the graphene while applying an electrical bias and monitored the resulting changes in electrical charge. These measurements allowed us to fundamentally explain the link between graphene, light, and generated charge carriers that enable cell neuromodulation.”

As the Nature Communications paper concluded about the huge research project, “In summary, this work presents graphene-based optoelectronic actuators for ultrafast, reversible, and efficient neuromodulation, establishing graphene as an active interface for precise…stimulation of neurons in both 2D and 3D systems, with broad applications spanning disease modeling, neurodevelopment, and bio-integrated robotics.”