Regenerative medicine is a fast-moving interdisciplinary field, combining stem cell therapeutics and tissue engineering with a range of other techniques to repair or replace cells, tissues or organs damaged by accident or disease. Simpler forms of tissue for transplantation grown from a patient’s own cells, such as skin, are already commercially available, but more complex organs are much harder to produce. Success depends on the highly precise manipulation of stem cells to specialise into different types of cells that comprise an organ, in combination with tissue engineering approaches to ensure that an appropriate tissue scaffold for the organ is present.
Now, the first transplant of a windpipe created by tissue-engineered stem cells into a ten-year old child has been successfully performed in the UK (see BBC news). The third and most ambitious procedure of this type created a longer tissue windpipe than that created for the two previous adult recipients – but in all cases, much of the new organ was grown from stem cells belonging to the patient, making the risk of immune rejection much lower than for a normal donor transplant.
The bone marrow-derived stem cells from the patient were used to colonise (or ‘seed’) a donor organ from which most of the functional cells had been removed to leave the structural collagen framework. The stem cells are expected to specialise into tracheal cells over time following the transplant. If successful, it is hoped that the same technique can be used more widely for similar procedures and for other organs such as oesophageal transplants.
The child’s own trachea was non-functional. Previous recipients of similar organs were both adult women from Spain and Italy, but in these cases the stem cells were grown on the tracheal scaffold for some days in the laboratory before transplantation (see BBC news).
Meanwhile, tissue engineering using stem cells is flourishing for a whole range of other medical applications. One recent report focuses on a new technique to grow bones from stem cells – in specific shapes suitable for transplantation (see New York Times).