Neural tissue model

Modeling the nervous system

The physiological and pathological mechanisms of the nervous system are of high interest in the fields of regenerative medicine and therapeutics. The complex organization of the central and peripheral nervous system, which includes the brain, spinal cord and neurons, can only be mimicked with 3D tissue models. Recent advances in 3D tissue models enable researchers to mimic tissue subunits and investigate neural regeneration, maturation and abnormalities. CELLINK provides the bioprinter and specialized bioink technologies needed to generate physiological 3D tissue models of various regions of the nervous system.

Aim

In collaboration with BrainXell, a U.S. provider of human-induced pluripotent stem cell (iPSC)-derived motor neruons and astrocytes, CELLINK is developing neural tissue-specific bioinks for specialized spinal cord neural cells, including motor neurons and astrocytes.

 

 

CELLINK products used

  • CELLINK LAMININK blend.
  • BIO X.

Specialized bioinks support neural network formation

In the first experiment, CELLINK mixed iPSC-derived motor neurons in a high concentration (30 million cells per mL bioink) with CELLINK LAMININK bioink. The constructs are small droplets generated using the Droplet Bioprinting function on the BIO X. The iPSC-derived motor neurons were GFP-labeled to enable easy live-cell monitoring under a fluorescent microscope.

 

After 17 days of culture, fluorescent microscopy showed network formation between clusters via motor neuron extensions from one cluster to another in all directions. This demonstrates the cell-cell behavior and cell-matrix behavior in 3D.

Self-organization of motor neurons

Using multiphoton microscopy, closer examination of the constructs conducted at the Center for Cellular Imaging in Gothenburg, Sweden showed that the cell clusters are made of loosely aggregating motor neurons with short extensions between cells. In addition, matrix accumulation is also evident between the cells.

 

In the video going through the sequential Z-plane images, the distribution and morphology of the cells (yellow) and matrix (white) can be seen.

Intracellular neural cell activity

Neural cell activity can be measured using a commercially available fluorescent calcium indicator on 3D-bioprinted neural tissue models. In a co-culture experiment of bioprinted human iPSC-derived astrocytes and motor neurons, a calcium indicator (green) was used to visualize intracellular calcium mobilization as an indicator of neural cell transmission activity. The video of green fluorescent flashes demonstrates neural action potentials after four weeks of culture.

Conclusion

In-house experiments demonstrated 3D bioprinting and bioink technologies are the ideal tools for developing neural tissue models and enhancing understanding of the nervous system. CELLINK’s LAMININK supports growth and network formation of motor neurons in 3D-bioprinted droplet constructs. In addition, the bioink supports the co-culture of astrocytes and motor neurons in proliferation and neural cell activity for long-term experimentation.