If you want to replace age-damaged tissue, you have to source the replacement from somewhere. A primary focus in the biotechnology research community is tissue engineering - building new organs from a patient's own cells, controlled and aided by a wide variety of helper technologies. The same underlying tools of biotechnology also make another source of organs available: xenotransplants grown in gene-engineered animals. An article from the UK press puts forward a timeline for clinical use similar to that for tissue engineered complex organs:
British scientists could be breeding designer pigs in just two years that would offer hope to transplant patients. ... Although the work, being carried out at Imperial College London, is still in the early stages, he is confident of producing the first designer pigs within two years. This means organs grown in pigs could be used in human transplants within a decade.
The research, presented at the British Association's Festival of Science in York, centres around tricking the body's immune system to believe that pig organs are human. This is done by creating pigs carrying genes which alter key molecules on the surface of organs, hiding their origin from the human immune system.
But EU regulations mean that the researchers have so far been refused permission to breed from the pigs. This, combined with a 13-month delay for Home Office approval to inject the gene into the pigs, means further research may be carried out in the U.S.
So far, the alterations to the pigs' sperm have only been temporary. But within two years, the scientists hope to have been successful in making long-lasting alterations - and in the birth of designer offspring. Many more years of work will then focus on using genes thought to be able to trick the human immune system, and, finally, on testing the technique on people, with human transplants ten to 15 years away.
A familiar story, and familiar ball and chain.
Regulation aside, xenotransplantation is likely to be competitive to tissue engineering for the forseeable future - perhaps right up until the time the two fields begin to blur and overlap. If an aspect of the biology of a different species is clearly superior to that of humans, and biotechnology offers us the ability to make use of that superiority, people will seize the opportunity. Perhaps more pertinently, ever increasing capabilities in biotechnology and molecular nanotechnology will, in decades to come, start to render cell structure, organ form, genes and even being biological a matter of choice. We are machines built upon machines, and soon enough there will be designers, repairmen, new versions and tremendous diversity.
The petty regulation and debate over every new advance in the first years of the 21st century will be seen as a parochial, fearful flight from opportunity by those who benefit from the biotechnologies to come.