Nanotechnology keeps promising, it looks like one day soon it could be delivering:
Nanotechnology May Create New Organs
Scientists have built a minute, functioning vascular system - the branching network of blood vessels which supply nutrients and oxygen to tissues - in a significant step towards building whole organs. Conventional tissue engineering methods have successfully grown structural tissues such as skin and cartilage in the lab. But not being able to create the supporting vascular system has proved a major stumbling block preventing scientists from creating large functioning organs such as liver or kidneys. Now, researchers from Massachusetts Institute of Technology and Harvard Medical School have used computers to design branching networks of venous and arterial capillaries, which start at three millimetres wide and reach a fineness of just 10 microns.
"We used living vessels as a guide to model factors such as the angle and size ratio between branching vessels. But we optimised our design to improve it," said lead researcher Mohammad Kaazempur-Mofrad, from MIT¹s department of mechanical engineering and division of biological engineering. The networks were etched on to 15 centimetre-wide silicon wafers and the paths were then used as a mould to set a layer of biodegradable polymer. Two of these were then sealed together with a microporous membrane sandwiched between them, producing a mini artificial vascular system.
Endothelial cells - which are flat cells lining the walls of blood vessels in a single layer - were injected into the network on one side of the membrane and either liver or kidney cells were injected on the other side. The endothelial cells coated the inside of the polymer nanotubes. These nanotubes biodegraded to leave a living shell of vessels similar to a natural vascular network. This method would provide an efficient means of supplying the liver or kidney cells with enough oxygen and nutrients to survive. The one-layer systems of kidney and liver cells were successfully implanted into rats for two weeks 95 per cent of the cells survived.
"The next step is to work on bigger animals, such as a pig or rabbit, using more layers," Kaazempur-Mofrad told New Scientist. "Eventually, we want to be able to replace whole organs with several layers of these constructs. The critical mass for liver is one-third, probably 30 to 50 stacked layers." "So in the next 10-15 years, we will hopefully have reached a point where we can do this procedure clinically in human patients," Kaazempur-Mofrad added.The research was presented at the American Society for Microbiology Conference on Bio-, Micro-, and Nanosystems, in New York City on Tuesday.
Source: New Scientist