Bioprinted Nerve Grafts

For the longest time, treating severe nerve damage has been a hassle and a challenging medical procedure. And a specific medical procedure has emerged that could be the solution to severe nerve injuries: Bioprinted nerve grafts.

According to Soman and Vijayavenkataraman (2020), the most common injuries that require the replacement of a piece of nerve tissue are crushing injuries, penetrating injuries, traction injuries, ischemia, lacerations, compression, and burns. These injuries significantly impact the quality of life for most individuals, leading to paralysis and neuropathic pain. Surgeons traditionally harvest nerves from another part of the patient’s body. This, however, produces a second surgical site and limits donor tissue. With the revolutionary discovery of Bioprinted Nerve Grafts, a perfect anatomical fit is ensured. 

According to Zhang et al. (2018), 3D bio-printing is a fabrication technology that precisely dispenses cell-laden biomaterials for the construction of complex 3D functional tissues or artificial organs. This process begins before the bioprinter is activated. It starts with medical imaging of the patient’s injury site, such as an MRI or a CT scan. This data is used to create a 3D digital model of the damaged nerve segment, making sure to include its diameter, length, and patterns. The blueprint for the graft is then created from this model. 

The next critical step is sourcing the “bioink”, the living material used for printing. The preparation of bioink for bioprinting involves the controlled addition of living cells to construct nerve parts that closely mimic natural tissues (Soman and Vijayavenkataraman, 2020). A small biopsy of the patient’s own tissue is taken. From this sample, specific cells are isolated and cultured. These two most crucial cell types are Schwann cells, which, according to the editors of Encyclopedia Britannica (2009), are each of the cells in the peripheral nervous system that produce the myelin sheath around neuronal axons. Another cell type is neural progenitor cells, which can differentiate into various nerve cells. These cells are then carefully mixed into a bioink. The hydrogel acts as a temporary, protective scaffold that mimics the natural extracellular matrix. This provides structural support and essential nutrients to keep the cells alive during and after printing. 

Once the digital model has been perfected and the bioink has been prepared, the bioprinting will start. The graft is designed as a structure containing multiple, hollow microchannels that serve as guides directing the sprouting axons. After printing, the graft is not immediately ready for implantation. It is first transferred to a bioreactor, which provides a controlled environment that mimics the human body. This allows the graft to “mature” and for the cells to gain strength before surgery. 

Finally, it is surgically implanted, attached to the two severed ends of the damaged nerve. This creates a biological bridge. Over the next few months,  the graft helps the nerves grow as the scaffold degrades. This leaves behind a stronger, and fully functional nerve.

Written by Sophia Perez at Incisionary

References:

Soman, S., & Vijayavenkataraman, S. (2020). Perspectives on 3D bioprinting of peripheral nerve conduits. International Journal of Molecular Sciences, 21(16), 5792. https://doi.org/10.3390/ijms21165792. Retrieved on September 20, 2025.

Zhang, Q., Nguyen, P. D., Shi, S., Burrell, J. C., Cullen, D. K., & Le, A. D. (2018). 3D bio-printed scaffold-free nerve constructs with human gingiva-derived mesenchymal stem cells promote rat facial nerve regeneration. Scientific Reports, 8(1). https://doi.org/10.1038/s41598-018-24888-w. Retrieved on September 24, 2025.

Encyclopaedia Britannica. (2009, April 9). Schwann cell | Definition, Function, & Facts. Encyclopedia Britannica. https://www.britannica.com/science/Schwann-cell. Retrieved on September 24, 2025.