New hope for transplant patients
Story and Photo by Hudson Lofchie
Published in The California Aggie (theaggie.org) on February 16, 2011)
Waiting rooms at the doctor’s office are stressful places; you wait nervously for your name to be called as you flip through the provided reading materials and compulsively check your watch, wishing you could be anywhere else except on the receiving end of a devilishly long needle. Now imagine that the waiting room you are in has 18,000 other patients in it, all of you have chronic liver failure and only a quarter of you get a transplant. That is the hell endured by everyone on the liver transplant list.
Liver failure is a relatively common occurrence. It can be caused by anything from acute and chronic liver disease, to acetaminophen overdose.
Luckily, researchers at the UC Davis Medical Center (UCDMC) are confronting this problem head on with some of the most amazing new medical technology. The method is called decellularization. According to a study published in the medical journal Liver Transplantation, decellularization involves “stripping all cells out of the organ while preserving its structure and blood supply framework.”
Using a decellularized liver as a “scaffold,” Jian Wu and his team of researchers implanted human liver cells into the structure, which was then inserted into the fatty tissue around a mouse’s abdomen. Wu is a doctor at the UCDMC Institute of Regenerative Cures, and head of the decellularization research team.
Essentially, you can think of a damaged liver as a skyscraper full of lazy workers. Decellularization is like taking every lazy worker out of the building, but keeping all of the offices, wiring and plumbing intact. Replacing the lazy workers with new, productive ones makes the liver healthy again. Obviously, this is far more efficient than tearing down the whole building.
Another huge benefit to this method is that it can utilize organs that normally would not be suitable for transplant. The problem with donor organs is that the longer an organ goes without blood and oxygen supply, the less likely it will be suitable for transplant.
“If cadaveric organs are available that are not suitable for transplant, they can be used to generate decellularized matrices, and possibly create new tissues or organs for transplantation or tissue engineering,” said Wu.
“[Decellularization] is a new approach versus whole organ transplantation, which is more complicated, more expensive and depends on the availability of donor organs that are in great shortage,” said Wu.
The method of decellularization has been around for a while, but until recently, the tissues generated from the process lasted only a few hours to a few days at maximum. Wu and the other UCDMC researchers managed to create tissues that functioned at least 60 days – long enough to keep a patient alive while waiting for a transplant. According to Wu, their work is the initial step toward long term efficacy where decellularization and recellularization would replace transplants all together.
“We have demonstrated the best results to date for the efficacy of transplanting cells into an animal model using a decellularized liver matrix,” said Wu.
However, there is a distinct downside to this method.
“The disadvantage is that this is a state-of-the-art tissue engineering technology that will take a considerable time to be clinically available,” said Jan Nolta, a professor of cell biology and human anatomy and the director of the UC Davis School of Medicine Stem Cell Program.
So far, the only tests done have been on lab mice, but the principles are sound, and it is only a matter of time until the process is refined enough for testing on human patients.