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Researchers from Rice University and Baylor College of Medicine (BCM) have broken one of the major roadblocks on the path to growing transplantable tissue in the lab: They've found a way to grow the blood vessels and capillaries needed to keep tissues alive.

Harvard researchers have created nanodevices made of DNA that self-assemble and can be programmed to move and change shape on demand. The nanodevice structure is based on the principle of tensegrity: its strength and stability results from the way it distributes and balances the counteracting forces of tension and compression. This new technology could lead to nanoscale medical devices and drug delivery systems, such as virus mimics that introduce drugs directly into diseased cells. Or it could one day be used to reprogram human stem cells to regenerate different kinds of injured organs and tissue.

The "ink" in the bioprinting process employed by Organovo is composed of spheres packed with tens of thousands of human cells. These spheres are assembled or "printed" on sheets of organic biopaper. By precisely placing the cells with the bioprinter, and providing them with the proper natural developmental cues, they do exactly what they do in nature: they self assemble into fully formed, functional tissue.

A 36-year-old man has received the world's first synthetic trachea, made from a synthetic scaffold seeded with his own stem cells, in an operation at the Karolinska University Hospital in Stockholm, Sweden. Professor Paolo Macchiarini of Karolinska University Hospital and Karolinska Institutet led an international team, including professor Alexander Seifalian from University College London, who designed and built the nanocomposite tracheal scaffold, and Harvard Bioscience, which produced a specifically designed bioreactor used to seed the scaffold with the patient´s own stem cells. The cells were grown on the scaffold inside the bioreactor for two days before transplantation to the patient. Because the cells used to regenerate the trachea were the patient's own, there has been no rejection of the transplant and the patient is not taking immunosuppressive drugs. "The big conceptual breakthrough is that we can move from transplanting organs to manufacturing them for patients," says David Green, the president of Harvard Bioscience in Holliston, Massachusetts. Transplantations of tissue-engineered windpipes with synthetic scaffolds in combination with the patient's own stem cells as a standard procedure means that patients will not have to wait for a suitable donor organ. Patients could benefit from earlier surgery and have a greater chance of cure. This would be of especially great value for children, since the availability of donor tracheas is much lower than for adult patients.