Bioprinting: A Revolutionary Technology to Address Organ Scarcity

Written By Vaishnavi Kolluru

Bioprinting is the process by which artificial tissues are 3D-printed. This technology has immense potential to solve the issue of organ donor scarcity; if implemented properly, bioprinted organs can provide life to the 106,000 patients currently awaiting transplants (“Organ donation statistics,” 2021). In addition, due to the precision required to produce an artificial organ, we need to intimately understand organ anatomy to implement this technology. This knowledge can also assist in addressing other anatomical abnormalities. Thus, bioprinting is an area of research that can yield tremendous knowledge and benefits, and should be further explored. 

Process

Creating artificial organs requires immense precision, as we must consider many factors. For example, the extracellular matrix of artificially constructed tissue should be compatible with, and appropriate for, the intended site of insertion. Additionally, production methods must address the possibility of immune rejection of a manufactured organ. Not only are compatibility checks important, but production practicality must also be considered. We should be capable of mass organ manufacturing with minimal unit-to-unit variation. In addition, materials should be biodegradable in case of excess production. Based on this idea, it is important to consider various bioinks while searching for the optimal material for bioprinting. 

One option is a protein-based bioink, which can hold immense quantities of water. Examples of naturally-occurring protein bioinks include collagen (gives strength to skin), gelatin (collagen derivative from hooves, bones, and other parts of certain animals), fibrin (clotting protein), and hyaluronic acid (lubricant in the joints). Their biodegradability is a major benefit, resulting from their biological origins. Thus, like other organic alternatives, protein bioinks are environmentally sustainable options for bioprinting.

Carbohydrates are also effective as bioinks. Alginate (alginic acid) is a polysaccharide derived from seaweed, and bears structural similarity to human extracellular matrix components. Many other polysaccharides, such as dextran (bacterial) or chitin (fungal) can be used for bioprinting as well. Conversion of carbohydrates into forms conducive to bioprinting is a simple, effective, and low-cost process that does not produce any toxic byproducts. This makes carbohydrate bioinks well-suited for sustainable bioprinting. 

Many other kinds of bioinks exist, too. Choosing a bioink is an important decision that requires knowledge of the intricate details of the target organ’s functions and surroundings. Scientists are developing computational models to account for these details, to choose the best bioink for each case. Another method for quality control is to test shape fidelity of bioinks by printing parallel strands. The accuracy of this printing provides valuable information about the precision of a particular bioink, and decisions can be made accordingly (Gungor-Ozkerim et al., 2018). 

However, the challenge of bioprinting extends beyond choosing the best bioink. To print a functional organ, it is necessary to ensure compatibility with the organ’s physiological environment. The organ should be able to form attachments to surrounding tissue to allow physical anchoring. In addition, the organ should connect to the recipient’s vasculature to ensure cohesive function within the body. The organ also needs to remain alive and functional ex vivo prior to transplantation, and for the rest of the recipient’s lifetime, properly serving the missing organ’s purpose in the body. Due to these challenges, bioprinting remains a developing technology (Matai et al., 2020). It is paramount to continue research in this area, as bioprinting will revolutionize transplant medicine.

Bioethics

However, while this technology has far-reaching medical benefits, it is important to consider ethics. If it becomes possible to print organs, should we invest in learning how to “print” whole humans? This extension could benefit couples struggling to conceive, who cannot use available reproductive technologies. For example, many couples are not eligible for IVF for various reasons, and experience frustration at their lack of options for conception. Additionally, reproductive technology failures make new options necessary. But is bioprinting for this purpose a morally sound approach?

It is possible to justify full-human bioprinting as “playing God” and therefore immoral; however, we must understand that, technically, all of medicine is, in some way, “playing God.” Vaccinations prevent “God’s will” of a viral infection. Reconstructive surgery fixes “God’s mistakes.” Thus, without some degree of “playing God,” we cannot effectively practice medicine. It is commonly accepted that medicine is moral, so, at this level, most people consent to “playing God.” Can we extend this consent to bioprinting? Opponents of creating artificial life argue that medicine is merely a change in life condition, whereas bioprinting would be a creation of life. Thus, medicine is not “playing God,” but rather “supplementing God” with medical advances. Religions don’t typically exclusively credit God with the changes of life; there still exists debate regarding God’s level of involvement in daily life. However, most religions do credit God with creation; in fact, many refer to God as some paraphrasing of “The Creator,” suggesting that creation of life is God’s main responsibility. Thus, according to these belief systems, creation of life is not a responsibility that humans can or should take over, as this is the job of God. However, because religious beliefs are so diverse, people struggle to form a consensus using the “playing God” argument. 

Thus we can take a “secular” argument, which considers the fairness of artificially creating humans. With creation comes a sort of creative freedom, in which the traits of the offspring can be manipulated, either genetically or by other means. However, is “customization” ethical? For any medical procedure, patient consent is required (if the patient is able to consent). We can consider “customization” to be a medical procedure, by defining medical intervention as a supplement to health. If this is the case, customization requires consent from the offspring. Obviously, an unborn child cannot consent to modification. Thus, it can be argued that bioprinting humans is unethical (Douglas et al., 2013).

Conclusion

Although the morality of human printing is debatable, the benefits of organ printing cannot be ignored. Organ replacement is the best therapy for patients with organ malfunction, due to improved quality of life; a functional organ is the best medicine in all aspects (Saidi & Hejazii Kenari, 2014). However, thousands of patients are dying while awaiting organ transplants: for example, in 2006, it was estimated that 6,300 of the 95,000 patients on waiting lists died, in the US alone (Abouna, 2008). That number is only increasing.

Organ bioprinting is a revolutionary technology that can solve the issue of donor organ scarcity. However, there exist ethical concerns about furthering this technology, and these must be taken into account when evaluating the extent to proceed.

Here are some interesting articles on this topic:

References

  • Organ donation statistics. (2021). Retrieved December 15, 2022, from https://www.organdonor.gov/learn/organ-donation-statistics 

  • Gungor-Ozkerim, P. S., Inci, I., Zhang, Y. S., Khademhosseini, A., & Dokmeci, M. R. (2018). Bioinks for 3D bioprinting: an overview. Biomaterials science, 6(5), 915–946. https://doi.org/10.1039/c7bm00765e.

  • Matai, I., Kaur, G., Seyedsalehi, A., McClinton, A., & Laurencin, C. T. (2020). Progress in 3D bioprinting technology for tissue/organ regenerative engineering. Biomaterials, 226, 119536. https://doi.org/10.1016/j.biomaterials.2019.119536.

  • Douglas, T., Powell, R., & Savulescu, J. (2013). Is the creation of artificial life morally significant?. Studies in history and philosophy of biological and biomedical sciences, 44(4 Pt B), 688–696. https://doi.org/10.1016/j.shpsc.2013.05.016.

  • Saidi, R. F., & Hejazii Kenari, S. K. (2014). Challenges of organ shortage for transplantation: solutions and opportunities. International journal of organ transplantation medicine, 5(3), 87–96.

  • Abouna G. M. (2008). Organ shortage crisis: problems and possible solutions. Transplantation proceedings, 40(1), 34–38. https://doi.org/10.1016/j.transproceed.2007.11.067.

Vaishnavi Kolluru
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