New method found to build artificial blood vessels!

Figure1, yellow: Number of People died on the kidney transplant waitlist, blue: Number of people removed from the waitlist classified as “too sick”. Source

As the research shows, there are more than 114000 people in the United State on the waiting list of life-saving organ transplants. On average, there will be one new name added to the list every ten minutes, and 20 people die because of the lack of available organs every day. Research team from the University of Minnesota Medical School has published their new founding in Nature Biotechnology on March 11st, 2020. Their research proved the possibility to build artificial blood vessels in a pig, which has the potential to provide ultimate blood vessels for human organ transplants.

How did they come up with the idea?

“There is so many chronic and terminal diseases, and many people are not able to participate in organ transplantation,” said Daniel, a cardiologist who accepted heart transplantation before, “About 98 percent of people are not going to be eligible for a heart transplant, so there’s been a huge effort in trying to come up with strategies to increase the donor pool. Our approach looked at a pig.” Due to the physiological similarity between human and pigs, scientists have done similar studies of using pig insulin to treat human diabetes. These historical researches give scientists confidence and also an existing platform to study.

What is the benefit of choosing pigs?

Figure 2:Acute rejection Anti-CD3 Donor DC. Source

Transplant rejection is a process of transplanted tissue rejected by the recipient’s immune system. According to the research done previously, there are 50-80% of patients would have at least one rejection episode. This symptom is due to recipient’s body cannot adapt to a “foreign” tissue and the immune system would fight against the transplanted tissue. Transplant rejection always causes severe consequences, and a lot of patients would have to remove the tissue immediately.

Daniel Garry, the leader of the research team came up with an idea to avoid transplant rejection. They took mature cells scraped off from a patient’s skin, reprogram these cells and eventually inject them into a pig embryo. This process would develop patient’s own genetic information in pig’s body. Thus, patients will get their own “blood vessels” which can greatly avoid transplant rejection. Mary, coworker of Garry said: “These blood vessels would be engineered and could be utilized in these patients to prevent those kinds of life-long handicaps, if you will.”

The first phase of their study has been approved by the University of Minnesota’s Stem Cell Research Oversight committee. “While it is a first phase, there’s pretty solid proof of concept,” Mary said. “We believe that we’ve proven that there’s no off-target effects of these cells, so we’re ready to move forward to later gestational stages.” This study will eventually benefit millions of people who are suffering from transplantation surgery. Also, this study shines lights and give hopes to modern organ transplantation studies.

-Vicky Gu