(556a) Neuron-on-a-Chip: A Novel Microfluidic Device for Neural 3D Tissue Culture

Research on neural tissue depends heavily on animal models. Although some in vitro models are currently in use, they are mainly based on the 2D culture of neurons and are far from properly recapitulating neural growth. Here, we present a simple and versatile neuron-on-chip system that we developed to enable fundamental studies on neural growth under chemical or physical gradients. The system consists of a 3D-printed module composed of three distinct compartments. The middle compartment contains a hydrogel matrix of gelatin methacryloyl (GelMA) and alginate which hosts a piece of forebrain tissue from an 8-day chicken embryo (E8). Culture medium is circulated through the upper compartment and permeates through the hydrogel matrix to provide a continuous supply of nutrients, by diffusion, to the neural tissue. Meanwhile, the lower compartment is fed for continuous removal of waste media. Chemical gradients can be established in the system by adding chemical cues to the top feed. Alternatively, physical cues can be embedded in the hydrogel matrix. Results from culture experiments using media supplemented with neural growth factors demonstrate the feasibility of reproducibly inducing and sustaining axon growth for at least 14 days, as characterized using image analysis techniques. In addition, we verified the expression of neural markers using PCR and immunohistochemistry techniques. We also observed that the use of hydrogel matrixes with different mechanical properties greatly affects the rate of axon growth and the degree of axon alignment.

Our results suggest that this simple neuron-on-chip system can be a useful tool for the in vitro study of neural growth.