- molded blood vessels that surgeons could take off the shelf and implant in patients may not be as exaggerated as they sound. Researchers report today Science Translational Medicine a new way to use human cells to produce blood vessels that can operate in people without asking an immune reaction. Unlike other engineering vessels, they can be stored up to 12 months, which could allow hospitals to keep on hand for immediate use in patients who need them.
Doctors perform transplants of blood vessels in heart bypass surgery and in dialysis patients. They often take the veins of a specific patient's legs or elsewhere in the body. But sometimes doctors can not find suitable containers and transplant tissue donors or even animals are not proven safe or effective. To meet the need in such cases, some researchers are increasingly sheets own cells of a patient in the laboratory and wrap to a ship. But the process is expensive and can take nine months or more, which is often too long for patients to wait.
Shannon Dahl several techniques, a tissue engineer at Humacyte, a biotechnology company in Morrisville, North Carolina, and colleagues combined to explore another way to produce blood vessels replacement. The strategy is to inoculate human smooth muscle cells, taken from corpses given on a tubular scaffold of biodegradable polymer called glycolic acid. As the cells grow to cover the scaffold, they produce collagen and other extracellular matrix (ECM) proteins that replace the scaffold degradation. The researchers then use a detergent to remove cells, leaving a blood vessel cell-free, the researchers speculated that could be stored for months and trigger an immune reaction in the recipient.
The researchers compared the vessels of a corpse seed cells given with those made from the cells pooled from several donors. The pooled cells produced ships as strong as those of individual donors. That's good news, Dahl said, because the pooling of these seed cells, it would be possible to grow more ships in a single batch, by lowering the cost of ships.
The researchers then transplanted blood vessels engineering in the arms of eight baboons. They remained functional and free of clots up to 6 months and do not appear to generate an immune response despite being composed of human collagen and ECM. Dahl and his colleagues also smaller-suitable vessels for bypass from coronary dog cells and transplanted them into five dogs, where they stayed clear blockages to one year. In both models, the new vessels were soon populated by several types of cells present in normal blood vessels, suggesting that the bodies of animals tolerate transplants.
Although the number of laboratory animals in the Dahl study was small, said Robert Nerem, a bioengineer at the Georgia Institute of Technology in Atlanta, the results are encouraging. The fact that engineering vessels can be easily stored suggests that surgeons could keep a supply on hand. "If you have to make bypass surgery, often it is not an elective procedure where you sit around waiting for weeks. You really want this to work on the shelf," he said.
Dahl said she and her colleagues are now "lay the foundation" for how they could start safely to test the vessels in human patients. Although the results are preliminary animal, she said they are encouraging enough that "it is interesting to assess our energy technology into the clinic."
0 Komentar