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About this Article
Written by: Nathan Saletan
Written on: April 1st, 2011
Tags: material science, biomedical engineering, health & medicine
Thumbnail by: B.E. Uygun
About the Author
Nathan Saletan is majoring in Computer Science and Business Administration with a minor in Mathematics and plans to graduate in May, 2013. He takes part in many extracurricular activities such as the After School Sports Connection, University Student Government and is the philanthropy chair for his fraternity, Phi Kappa Psi.
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Volume XIV Issue I > Tissue Engineering: Growing Human Livers?
Current research in tissue engineering may soon offer a solution to the rising number of people waiting for livers. Recent research has shown promising breakthroughs; In June, 2010 researchers at the Massachusetts General Hospital in Boston managed to successfully transplant an artificial liver into a rat. This research also has the potential to advance other scientific processes, such as how pharmaceutical companies would be able to test drugs on extra livers instead of humans or animals. The scaffolding process, however, is not without hurdles. One major problem is that current working scaffolds come from human donors, meaning that this current process produces no net gain.

No More Organ Donations

Imagine the day when organ donors are no longer necessary. Organs, instead, would be grown, eliminating the anxiety of being placed at the end of a list, hoping to be lucky enough for an organ donation. Instead of taking livers, kidneys, lungs or any other transplantable organs from the deceased, the organs would be grown in a laboratory. Although this concept appears to have emerged from a science fiction novel, it is closer to becoming a reality than you may think. Tissue engineering may provide the answer in the near future. Researchers for the first time in June 2010 managed to artificially grow a liver in a laboratory and successfully transplant it into a rat [1]. This breakthrough is the first of its kind for tissue engineers trying to grow livers in a laboratory.

Dealing with Liver Disease

As of February 2011, over 17,000 Americans are on the waiting list for a liver transplant [2]. Last year, there were 6,300 liver transplants performed while 1,400 passed away waiting for a donor [1]. Liver disease is a serious problem in the United States; livers are only second to kidneys as the most commonly transplanted organs. A transplant is necessary regardless of the cause of liver disease: cancer, alcoholism, hepatitis, or any other of the many ailments. There is, unfortunately, currently no alternative to transplantation.
The first successful human liver transplantation was performed in 1967 by a surgical team lead by Dr. Thomas Starzl, a professor at the University of Colorado [3]. By the 1980’s, the technique had become an accepted treatment and patients had approximately a 25% chance of surviving for one year following the surgery [3]. Since then, the development of Ciclosporin, an immunosuppressant drug that helps control the adverse reaction of the patient’s immune system with the foreign liver, has reduced organ rejection and increased survival rate. Currently, 87% of all recipients will survive for at least a year, and 58% have survived for at least 15 years [2].

The Science of Growing Organs

Daily Mail UK
Figure 1: A trachea inserted into a boy's throat, allowing it to naturally develop with the body.
The growing list of people needing a new liver and the limited number of donors has caused a significant amount of new research in the study of materials and cells to understand tissue function and regeneration. The ultimate goal of tissue engineers is to determine an effective method for growing organs suitable for transplantation (Fig. 2). While this may seem unrealistic at this moment, researchers are having increasing success. A recent success case, for instance, is an eleven year old boy from London who received a brand new trachea grown from his own stem cells in 2010 (Fig. 1) [4]. The ability to grow organs would greatly increase the amount of organs available for transplantation and furthermore allow the organs developed to be customized to each patient’s immune system.
Hinnovic
Figure 2: Rat liver after detergent is added to remove cells, leaving blood vessel intact.
Researchers have achieved major breakthroughs in the past five years, with the most promising experiments managing to grow liver cells in a laboratory. In June, 2010 researchers at the Massachusetts General Hospital in Boston managed to successfully transplant an artificial liver into a rat [1]. Although the rat only survived for several hours, it was determined that the lab-grown liver was capable of breaking up toxins – the primary function of the organ. Further experimentation aims to determine methods to grow livers on a larger scale that will be accepted by the recipient’s immune system.