• The global organ shortage means that many patients die before transplants are available.
  • An emerging field called tissue engineering works on producing artificial tissue and organ substitutes as permanent solutions to organ damage.
  • Biomedical engineering researchers are developing 3D temporary organ structures called scaffolds.
  • These could help regenerate damaged tissues and potentially lead to creating artificial organs.

Due to the global organ shortage and limited organ donors, thousands of patients are left wanting organs and tissues in cases of severe injuries, illness or genetic conditions. Many of these patients die before transplants are available.

Tissue engineering is an emerging field that works on producing artificial tissue and organ substitutes as permanent solutions to replace or repair damage.

As biomedical engineering researchers, we are developing 3D temporary organ structures — called scaffolds — that may help regenerate damaged tissues and potentially lead to creating artificial organs. These tissues can also be used in various tissue engineering applications, including nerve repair in structures constructed from biomaterials.

Printing tissue

Approximately 22.6 million patients require neurosurgical interventions annually around the world to treat damage to the peripheral nervous system. This damage is primarily caused by traumatic events such as motor vehicle accidents, violence, workplace injuries or difficult births. It is anticipated that the cost of global nerve repair and regeneration will reach more than $400 million by 2025.

Current surgical techniques allow surgeons to realign nerve ends and encourage nerve growth. However, the incidence of recovery in the injured nervous system is not guaranteed, and the return of function is almost never complete.

Animal studies on rats have shown that if an injury destroys more than two centimetres of nerves, the gap cannot be bridged properly and may result in the loss of muscle function or feeling. In this condition, it is important to use a scaffold to bridge two sides of the damaged nerve, specifically in case of large nerve injuries.

a diagram showing how large nerve injuries (larger than 2 cm) need a scaffold to act as a bridge to connect two sides of the injured nerve.
Large nerve injuries (larger than 2 cm) need a scaffold to act as a bridge to connect two sides of the injured nerve.
Image: Saman Naghieh

3D bioprinting prints 3D structures layer by layer, similar to 3D printers. Using this technique, our research team created a porous structure made of the patient’s neural cells and a biomaterial to bridge an injured nerve. We used alginate — derived from algae — because the human body does not reject it.

While this technique has not yet been tested in people, once refined, it has the potential to help patients waiting for tissues and organs.

Material challenges

Alginate is a challenging material to work with because it collapses easily during 3D printing. Our research focuses on the development of new techniques to improve its printability.

For nerve repair, alginate has favourable properties for living cells growth and functions, but its poor 3D printability considerably limits its fabrication. It means that alginate flows easily during the printing process, and results in a collapsed structure. We developed a fabrication method where cells are contained within a porous alginate structure that is created with a 3D printer.

Previous research used moulding techniques to create a bulk alginate without a porous structure to improve nerve regeneration; the cells do not like such a solid environment. However, 3D-printing a porous alginate structure is challenging and often impossible.

Our research addresses this issue by printing a porous structure made of alginate layer-by-layer rather than a moulded bulk algiante; such structure has interconnected pores and provides a cell-friendly environment. Cells can easily communicate with each other and start the regeneration while the 3D-printed alginate provides a temporary support for them.

image of a 3D printed, artificial ear
A 3D printed, artificial ear made of biomaterial and cells.
Image: Saman Naghieh

Researchers are going towards the implementation of 3D-printed structures for patients who suffer from nerve injuries as well as other injuries.

What is the World Economic Forum doing about the Fourth Industrial Revolution?

The World Economic Forum was the first to draw the world’s attention to the Fourth Industrial Revolution, the current period of unprecedented change driven by rapid technological advances. Policies, norms and regulations have not been able to keep up with the pace of innovation, creating a growing need to fill this gap.

The Forum established the Centre for the Fourth Industrial Revolution Network in 2017 to ensure that new and emerging technologies will help—not harm—humanity in the future. Headquartered in San Francisco, the network launched centres in China, India and Japan in 2018 and is rapidly establishing locally-run Affiliate Centres in many countries around the world.

The global network is working closely with partners from government, business, academia and civil society to co-design and pilot agile frameworks for governing new and emerging technologies, including artificial intelligence (AI), autonomous vehicles, blockchain, data policy, digital trade, drones, internet of things (IoT), precision medicine and environmental innovations.

Learn more about the groundbreaking work that the Centre for the Fourth Industrial Revolution Network is doing to prepare us for the future.

Want to help us shape the Fourth Industrial Revolution? Contact us to find out how you can become a member or partner.

After the fabricated alginate structure is implanted in a patient, the big question is if it have enough mechanical stability to tolerate the forces applied by tissues in the body. We developed a novel numerical model to predict the mechanical behaviour of alginate structures.

Our studies will help to understand cell response, which is the main factor to take into account when evaluating the success of the alginate structures.