“Why can’t we just print more organs?” Overcoming the organ shortage crisis with Bioengineering

Globally, the demand for organ transplants exceeds supply. In the United States as of 2021 116,566 patients were waiting for an organ transplant, 6 564 patients died waiting for an organ. Despite this, only 41 354 transplants were performed (Kupiec-Weglinski 2022). 3D bioprinting is an emerging technology that offers a promising solution by creating bioengineered organs and tissues, reducing patients left waiting for life-saving treatments and reliance on human donors (Bose, 2023)

3D bioprinting is an innovative technology that involves printing layer by layer, combining biomaterials, bio-inks, and living cells (Panja et al., 2022). This provides an opportunity to engineer human tissues and organs for medical use such as :

• Drug testing on human models (more reliable and reduces demand for animal models)
• Custom implants
• Reducing the waitlist for replacement human organs

How It Works

There are 4 main bioprinting techniques

(Panja et al., 2022)

Applications

Recently there have been significant breakthroughs in replicating complex human organs especially hollow organs such as the lungs, heart, and digestive system. Despite the immense progress, technical challenges still persist.

Bioprinting Lungs 

• Lung diseases such as COPD and COVID-19 have increased demand for lung transplants. The focus remains on the airways and alveoli.  Advancements have been made in the development of artificial alveolar models using inkjet printing, hydrogels, and synthetic polymers.  Despite this, these have not been applied to organ replacement yet (Panja et al., 2022). Achieving the highly complex structure and function of alveoli is still a significant hurdle. 

3D Printed Heart Tissue 

•  A heart has been bioprinted including blood vessels. This is crucial when developing the functionality of replacement organs. This was achieved using a technology called Coaxial Sacridicial Writing in Functional Tissue. This adds layers of real blood vessels, blood supply is essential for sustaining all bioprinted organs (Brownell, L. 2024).

Digestive System 

• Researchers have also seen developments in the bioprinting of the digestive system, including stomach, intestines and bile ducts. There is enormous potential for this to revolutionize drug testing and reduce reliance on animal models. However, barriers remain due to the inability to replicate the mechanical processes of the digestive system such as peristalsis(Panja et al., 2022. 

Challenges and Ethical Concerns

• Cost: Bioprinting is an expensive technology, with significant costs from research, development, and clinical trials. As well as the extensive laboratory equipment, this means that the early technology is likely to be limited to the wealthy (Bose, P., 2023).
• Tissue Vascularisation: functional blood vessels are imperative for delivering oxygen and nutrients, and keeping tissues alive. Functional blood vessels are challenging due to their microscopic size and complexity (Panja et al., 2022).
• Regulation and Safety: international regulations are necessary to ensure safety, efficacy and ethics have been taken into consideration (Brownell, L. 2024).

Conclusion

3D printing has the potential to make fully functional, transplantable organs a reality. There needs to be a focus on personalization to reduce the risk of elimination. However, vascularisation will remain a significant barrier to applicability. However, the potential to remove donor waitlists and animal models.

Could we be entering an era of on-demand organ transplants?

Bibliography

Bose, P. (2023). Bioprinting Organs: A Look into the Future of Transplantation. News-Medical. Available at: https://www.news-medical.net/health/Bioprinting-Organs-A-Look-into-the-Future-of-Transplantation.aspx [04/03/25].

Brownell, L. (2024). 3D-printed blood vessels bring artificial organs closer to reality. Harvard John A. Paulson School of Engineering and Applied Sciences. Available at: https://seas.harvard.edu/news/2024/08/3d-printed-blood-vessels-bring-artificial-organs-closer-reality [04/03/25].

Panja, N., Maji, S., Choudhuri, S., Ali, K. A., & Hossain, C. M. (2022). 3D Bioprinting of Human Hollow Organs. AAPS PharmSciTech, 23(5), p.139. Available at: https://doi.org/10.1208/s12249-022-02279-9 [04/03/25].

Kupiec-Weglinski, Jerzy W. ‘Grand Challenges in Organ Transplantation’. Frontiers in Transplantation 1 (6 May 2022). https://doi.org/10.3389/frtra.2022.897679. [04/03/25]