Direct laser writing of microstructures for the growth guidance of human pluripotent stem cell derived neuronal cells

• We fabricated cell growth guidance microstructures via direct laser writing.
• We designed and fabricated three novel neurocage microstructures.
• We seeded the neurocages with hPSC derived neuronal cells to study growth guidance.
• Proof-of-concept cell culture study showed promising neurite guidance properties.

Studying neural networks in vivo is very laborious due to the location and immense complexity of the central nervous system. Therefore, neuronal cell culture models have become important tools to study the development of neuronal networks in vitro. We introduce a technique called direct laser writing (DLW) by two-photon polymerization (2PP) as a feasible method for the fabrication of microstructures for studying neuronal cell growth guidance. As human pluripotent stem cells (hPSC) can be differentiated into several cell types, such as neurons, astrocytes, and oligodendrocytes, they are a promising cell source for cell culture models. In this study, three novel designs of neurocage microstructures were fabricated for the first time by 2PP. As a proof of concept, two of the neurocage designs were seeded with hPSC derived neuronal cells to study cell attachment, migration and directed neurite growth. Although the fabricated neurocage structures could not confine the neurons, the preliminary cell culture tests showed that neurons had a tendency to migrate towards the microstructures. In addition, the neurite guidance properties of the structures appeared promising as the neurons inside the cages readily extended their processes along the channels.