Human spare organs like brain organoids and liver buds can now be grown from stem cells.
Liver Buds to the Rescue
The number of patients needing liver transplants outmatches the amount of livers available for both America and Japan.
Yokohama City University’s Takanori Takebe, resident stem cell biologist, and his team from their Department of Regenerative Medicine were motivated to look for a more sustainable alternative to this problem. Their solution was to create liver buds or miniature livers from a person’s skin that’s turned into stem cells. They then reprogrammed the cell to revert to its embryonic state capable of becoming any type of cell, and their experiments were a success.
The team of Takebe managed to recreate how a human embryo develops a functioning liver by mixing the lab grown liver cell with two other types of cell where they arranged themselves into the liver like structure with blood vessels too.
The scientists then tested the human liver bud onto a mouse where they transplanted it. They found that the liver bud performed the functions of a mature organ like metabolizing drugs and sugars. The liver kept the mouse alive even after they disabled its own liver.
Patients receiving the liver buds for now will rely on immune suppressing drugs to keep the body from rejecting the transplant, until the scientists can find a way to grow them using a patient’s own skin.
Though science is still far from growing a spare human brain, they succeeded in using stem cells to grow brain organoids that copy some regions of the brain.
Growing the miniature brains required stem cells of two types – adult and embryonic stem cells. The cells were then placed in a specific culture and soaked in nutrients that stimulate the cells to grow into neurons found in the brain, where they organized themselves and started to form into a 3D structure.
By looking at it from afar, it doesn’t resemble a brain, but the functions and the connections found in the different areas of the brain are present.
The scientists also conducted an experiment using skin cell from a patient with microcephaly, which causes the brain to shrink. The results showed that the brain organoid grown from the tissue of the afflicted was smaller when compared to organoids grown from healthy tissue.
For now, the organoids are used to model the brain and its development so that scientists can understand what causes dysfunction and diseases, and be able to prevent them in the future.
Stem Cells from Human Eggs
The first ever successful cloning was back in 1996 with Dolly the sheep. Scientists managed to fuse skin cell with an egg cell called somatic cell nuclear transfer or SCNT, where they replace the nucleus of the egg cell with the nucleus of the skin cell thus altering its DNA, and coaxing it to start dividing, thinking it is fertilized by a sperm cell.
A genetic copy of the embryo, almost perfect, of the skin cell donor is the result. This is where stem cells are now taken, by making embryos and harvesting them from it, to be potentially used to replace organs, heal injuries and cure diseases.
Though the procedure is very tedious and complicated, the goal of scientists is to one day grow tissues or organs that would integrate with the body and won’t be rejected, to someday cure diseases and repair and regenerate what has been damaged in the body.