Regenerating Organs Using Stem Cells
Organ Shortages
Statistics
As of March 2019, nearly 114,00 people living in the United States have been placed on the wait list for an organ transplant. On average, around 20 people die per day waiting for organ transplants. Every 10 minutes, another patient is added to the transplant list (B6).
The number of transplants needed is decreasing, however in 2017 the number of transplants needed is still astronomically high (B6).
Explained by UNOS, in 2018 there were more successful transplants than ever before (B7).
In 2018, this was the amount of transplant per organ type (B7).
Percentages of different organ transplants from January 1, 1988 - January 31, 2019. Pancreas was listed as 1.2%, kidney/pancreas transplants had an average of 3.1% , and intestine was listed as .4% (B7).
Regenerative Medicine
What is It?
Regenerative Medicine is used to replace tissue or organs that have been damaged by disease or trauma. Scientist aim to use regenerative medicine as a way to restore structure and function of run down tissues and organs. Regenerative medicine focuses on using many different tactics to replace tissues and organs. Some of these practices are; cellular therapies, tissue engineering and bio-materials, 3D organ printing, skin grafting, and the development of new medical devices (B3, B4, B5, B8).
Did You Know?
The human skin and liver are self-regenerative organs, meaning that when injured they have the ability to heal itself, and grow back. These organs grow back to their similar shape and size, but not their exact original shape and size (B9).
The picture on the right shows how a small chunk of a donor liver can grow back to full size in the transplant patient's body, with in just two months (B12).
Explains some of the different practices scientist are developing in the field of regenerative medicine (B10).
How Can Stem Cells Help?
Stem cells can help repair damaged organs and tissues if injected into to the injured area and under the right circumstances. This process is known as stem cell replacement therapy. So far, laboratories have have been experimenting with somatic stem cells and have found that a single strand of adult stem cells can be used to generate an entire organ. So far "[t]wo laboratories have reported independently that single stem cells isolated from adult mouse mammary glands are able to produce secretory mammary glands... " (BMC). Using embryonic stem cells, scientist have also found that when pluripotent stem cells are injected into blastocyst cells, a new organ can form. "Generation of pancreas and kidney via blastocyst complementation is an innovative approach. It demonstrates that this technique can be used to generate complex organ using donor PSCs" (BMC). This experiment took place using human blaystocyst cells and injecting them into mice to develop full functioning pancreas and kidneys. Following this study, scientist have found that once the mice grew into adults, their generated organs upheld well, and the rats lived stable healthy lives. Another treatment option using stem cells is decellularization-recellularization technique. " [E]xtracellular matrix (ECM) is isolated from its native cells and genetic material in order to produce a natural scaffold" (NCBI). In this technique once ECM (extracellular macromolecules that support its surrounding cells) are derived from its genetic material and native cells (the cells its supporting structurally), they can be recellularized to form functioning organs. This technique is most commonly used for patients who suffer from trachea disorders (B1, B4, B5, B8).
Extracellular matrix is shown to illustrate the isolated stem cells from it's native state (B14).
A Real World Experience
Hannah Warren, who is 2 years old, was born with out a trachea. Hannah is the first and youngest patient to ever receive this type of transplant in the United States. Dr. Paolo Macchiarini was able to "carefully [create] the windpipe using stem cells from Hannah’s bone marrow that were saturated over a matrix of plastic fibers shaped into a tube" (TIME). The technique used to create her wind pipe was decellularization-recellularization using ECM cells. Hannah was given a 1% chance to live at birth, but after receiving the transplant was almost able to breathe on her own before passing away 3 months after receiving the transplant (B2).
Pictured, Hannah Warren and her parents visiting after her transplant surgery. Click on the photo to view her whole story (B2).