Innovative graphene-based neuronal interfaces!

Graphene‐based materials can be tailored to realize advanced interfaces for biomedical applications, with promising prospects for prostheses, biosensors and, particularly, neural interfaces. Although recent studies demonstrated the biocompatibility of graphene‐based interfaces, the biological interactions between graphene and neurons still pose open questions.

A group of researchers led by Dr Andrea Capasso explored this issue in a paper entitled “Interactions between Primary Neurons and Graphene Films with Different Structure and Electrical Conductivity”, recently published on Advanced Functional Materials (via open access). The work stems from an international collaboration among Portuguese, Italian, Spanish and South Korean institutions. In the paper, the authors investigated the influence of graphene films with different electrical and structural characteristics on the growth and maturation of primary cortical neurons.

Graphene films were fabricated by chemical vapor deposition of ethanol in a wide range of temperatures to tune their structural and electrical properties. A detailed investigation by Raman spectroscopy offered a full account of the modification induced in the graphene-based films by the process temperature. This Raman spectroscopy study (figure below) could be of use in many technological fields, guiding the researchers in the selection of the right CVD parameters to obtain a graphene interface with on-demand features.

Two graphene interfaces with opposite electrical properties (grown at 790°C and 1070°C, respectively) were selected and deposited on a PET substrate for the growth of primary cortical neurons. Fluorescence and electron microscopy imaging (shown below) revealed excellent neuronal viability and the development of a mature, structured, and excitable network on the two graphene substrates.

These findings suggest that a high electrical conductivity by itself is not a fundamental requirement for graphene-based neuronal interfaces. Other physicochemical characteristics of the graphene film, including the atomic structure, should be then considered in the design of functional neural interfaces. As a result, this work opens a new route widening the spectrum of carbon‐based materials suitable for neuroscience applications.

(A. Capasso, J. Rodrigues, M. Moschetta, F. Buonocore, G. Faggio, G. Messina, M. J. Kim, J. Kwon, E. Placidi, F. Benfenati, M. Bramini, G. H. Lee, N. Lisi. “Interactions between Primary Neurons and Graphene Films with Different Structure and Electrical Conductivity”, Advanced Functional Materials 2020, 2005300.)