Towards Multimodal Brain Reading: Advancements in Material Science and Microfabrication Techniques

4th April 2024

Timing : 1 pm EST

Please use this zoom link for joining the webinar

For a list of all talks at the NanoBio seminar Series Spring'24, see here

The real-time measurement of neurochemical and electrophysiological activities in the living brain is of utmost importance for uncovering fundamental principles in neuroscience and providing therapeutic intervention in a variety of neurological and psychiatric disorders. Devices capable of multimodal readings of neural signals in vivo for extended periods of time are a key technological bottleneck.

Microfabricated multielectrode arrays (MEAs) are routinely used for measuring neurophysiological activity from multiple sites across different brain depths. Flexible MEAs on polymeric substrates seamlessly integrate with neural tissue and record stable neural signals for months. However, MEAs with metal microelectrodes present poor sensitivity towards electroactive neurotransmitters, such as dopamine and serotonin, when using direct electrochemical detection. Carbon is considered the ideal material for electrochemical sensing and presents superior electrochemical stability. The use of carbon materials as a substitute for metal in conductive electrodes and interconnections in flexible MEAs would facilitate multimodal electrochemical and electrophysiological recordings.

To address the dual need for multimodality and implant stability, we developed flexible implantable carbon-based MEAs, achieving multiscale time resolution readings with an electrochemically stable device/tissue interface.

Here, I will provide an overview of the material strategies, microfabrication techniques, and electrochemical methods utilized in the development of this multimodal platform, and summarize the results obtained both in vitro and in vivo. Finally, I will discuss potential enzyme immobilization strategies and antifouling coating to further expand our platform's capabilities by enabling the electrochemical detection of non-electroactive neurotransmitters, such as acetylcholine and glutamate, thereby broadening the platform's applicability in neurochemical monitoring.

Dr. Elisa Castagnola
Assistant Professor
Department of Biomedical Engineering
Louisiana Tech University

Dr. Castagnola received her PhD in Robotics, Neurosciences and Nanotechnologies from the Italian Institute of Technology (IIT) in April 2011. She continued to conduct her postdoctoral research on neurotechnology at IIT, Departments of Robotics Brain and Cognitive Sciences, and Center for Translational Neurophysiology for Speech and Communication. She moved to the United State in 2017, working as a senior researcher and adjunct assistant professor at the Department of Mechanical Engineering at San Diego State University in Dr. Kassegne’s lab, supported by the Center for Neurotechnology, a National Science Foundation Engineering Research Center.

At the end of 2018, she joined the Department of Bioengineering of the University of Pittsburgh in the Neural Tissue Engineering (NTE) Lab, led by Dr. X.T. Cui, working on the development and in-vivo validation of multimodal neural probes, while serving as instructor at the undergraduate and graduate programs of Bioengineering.

Currently, she is an Assistant Professor at the Department of Biomedical Engineering at Louisiana Tech University. The Neural Electrode Interface Technologies Lab, led by Dr. Castagnola, focuses on (i) the development of flexible implantable neural probes for chronic multimodal electrophysiological and electrochemical sensing; (ii) the optimization of biocompatible materials and electrochemical techniques to enable neurotransmitter detection at different time scales, and (iii) in vitro and in vivo testing of the material stability and chronic performance of these devices.

Dr. Castagnola is supported by the NIH to develop a novel implantable sensor capable of measuring serotonin while simultaneously evaluating neural excitability in the development of neuropathic pain. This collaborative project involves partners from The University of Pittsburgh (Dr. X.T. Cui) and UT Dallas (Dr. Ben Kolber).

Dr. Castagnola’s main interests focus on material science, microfabrication, electrochemistry, neurochemical and electrophysiological sensing, and neural stimulation.