Organ transplants have been a lifesaving development and one of the shining success stories of modern medicine. But the shortage of organs for transplantation is an ongoing problem. One answer is to grow them artificially in a laboratory - a promising although controversial solution. Simple lab-grown organs are already being used in patients but challenges remain in creating complex parts. For this, researchers are now experimenting with pigs" livers. "Pigs... their size is closer to a human liver," said Abritee Dhal, a researcher in the US, at Wake Forest University in North Carolina. So, if we're able to decellularise and put human cells back in there, it could help with the shortage of organs that are needed for patients who are suffering from liver disease, or people who need kidneys. Researchers start by washing piglet livers in a process called "decellularisation," which removes the pig's cells but leaves the underlying structure intact. The hope is to put human liver cells into that structure to see if they can grow and multiply into a fully functioning human liver. Many different cell types create these tissues and organs, but our preference is to use a patient's own cells, and the patient's own organ-specific cells, because those cells already know what to do. A windpipe cell already knows that it's a windpipe cell, and it's going to create a windpipe cell for that patient that will not be rejected or kicked out," said Dr Anthony Atala, the Director of the Wake Forest Institute for regenerative medicine at Wake Forest University. The lab is also trying to make kidneys with 3D printers, using cells as the "ink." It's an exciting development, but the ability to grow and implant complex vital organs in humans is still a long way off. More about: Medical research