Thursday, 27 February 2014

Human Lungs made from Stem Cells for the First Time

In a remarkable scientific breakthrough, scientists at the University of Texas Medical Branch has created a human lung in the laboratory. Research into the process of developing new lungs started in July 2010.

In experiments on rats, the scientists stripped down rat lungs from all cells by a process of freezing and thawing and exposure to detergent. This caused only the scaffolding of the lungs, composed of structural protein like collagen and elastin tissue, to remain. This acellular scaffold was then seeded with  mouse embryonic stem cells. The cells thrived on this scaffold and developed into new lungs .

The lung is one of the most complex organs in the body - the   cells in the respiratory tree ( trachea and bronchii) is different from the cells in the alveoli (small air sacs). These different cells were successfully grown in the experiment.

On 14th February  this year, the scientists  could repeat the process in human lungs. Lungs were taken from two children who had died from a trauma. The lungs were too damaged to be used for transplants but still had some healthy tissue.

One of the lungs was used as the scaffold by stripping away all cells. Cells from the other lung was was then seeded onto the scaffold. The structure was then immersed in a  media containing nutrients and stimulating factors (placed in a fish tank bought from a pet store!). And in about 4 weeks, the human lung emerged.

The picture on the left is of the scaffold  of collagen tissue. Image B is of the lungs after they have  formed - they look pinkish and dense because of the   new cells.

The scientists have managed to repeat the process successfully in another two children who had died.

Lungs developed from stem cells will probably become available for transplants into humans after about 12 years. They will be first transplanted into pigs to see how well they perform in the body.

This is an exciting step forward in regenerative medicine. For people who suffer from  serious respiratory conditions like COPD and Cystic Fibrosis, lung transplants often provide the only hope for long term survival. Many persons die of the disease before a matching donor can be found. The successful engineering of human lungs in the lab for the first time provides a definite ray of hope  for humans.

No comments:

Post a Comment