Recent research has shown that ‘bioengineered’ blood vessels can be used for incorporating living cells following implantation in the human body. These vessels can become blood-carrying, self-healing tubes that can function as alternatives for human blood vessels. They have been given the name of human acellular vessels (HAVs) and are experimental devices as of yet.
Human acellular vessels might someday find their applications in treating medical problems including cardiovascular disease to gunshot wounds. The research has been described in the journal Science Translational Medicine on 27th March. According to Lola Eniola-Adefeso, a biomedical engineering professor at a university, ‘this is the wave of the future’.
A team of scientists and biomedical engineers at Yale University and Humacyte – regenerative medical technology firm in Durham, North Carolina – created human acellular vessels by obtaining arterial cells from cadavers and growing them into new vessels and then discarding the cells. Once the processing was complete, all that was left was the cellular matrix – an array of collagen and protein that provide the vessel with its structure.
The human acellular vessels were then implanted into the arms of 60 kidney disease patients in Durhan, Norfolk, Virginia, and three cities in Poland. The HAVs were utilized during three weekly sessions of hemodialysis – the blood cleansing treatment that is used for ailing kidneys. Hemodialysis is administered by means of a fistula or via graft. Both methods have their shortcomings; grafts are prone to clots and infections whereas not all patients are good enough candidates to quality for fistulas.
The researchers monitored the patients for a total of three years after they had received their implants. Every time the patient was called in for routine surgery or for maintaining their implant, the team would collect a small square of the artificial vessel. The researchers collected samples from 13 patients and carried out an analysis to find that the prebuilt matrix had been filled with the cells of the patients.
Humacyte CEO Jeffrey Lawson said, ‘Your own stem cells crawl into the spaces, realize that they’re in a blood vessel, and then differentiate into your own tissue.’ As per the analysis, the artificial vessels were able to heal themselves as well. Lawson further said, ‘This sci-fi notion of tissue engineering — we’re on the doorstep of doing it for real.’