An article on a successful transplant of a recellularized organ is doing the rounds in the mainstream press:
First a section of trachea was taken from a donor and stripped of cells that could cause an immune reaction, leaving a grey trunk of connective tissue. Stem cells were then taken from Ms Castillo’s bone marrow and grown in Professor Birchall’s laboratory. Stem cells can develop into different kinds of tissue, given the right chemical instructions, enabling researchers to cultivate cartilage and epithelial cells to cover the 7cm graft. It was then “seeded” with the new cells using a process developed in Milan. Finally the trachea, covered in cartilage and lined with epithelial cells, was cut to shape and fitted.
Professor Macchiarini said: “The probability that this lady will have rejection is almost zero. She is enjoying a normal life, which for us clinicians is the most beautiful gift.”
You might recall other news from past months on this technique for converting a donor organ into an organ built with the patient's own cells. In essence this is a clever way around the present inability to construct nanoscale scaffolds that have both the right structure and can provide the right biochemical signals to guide cell growth. The extracellular matrix left behind after the old cells are removed becomes that scaffold:
As you might guess from those two posts, much of the published recellularization work to date has focused on building new heart valves - or even complete hearts. It seems that any comparatively simple tissue structures are well within reach of present day tissue engineering, however. A decade from now, this sort of replacement for damaged organs will be commonplace.