RTP company engineers blood vessels

Growing spare body parts in the laboratory was a wild idea when Dr. Laura Niklason entered the field of tissue engineering. The former Duke University researcher who's now at Yale University remembered that even colleagues laughed in her face.

In the 12 years since then, scientists have figured out how to coax cells into making skin, cartilage and even bladder tissue for surgeons to implant in patients. But other body parts have proved more difficult to make in the lab. Blood vessels, for example, are tricky because of their shape and function.

But Niklason and two former Duke students, Juliana Blum and Shannon Dahl, have been working on replicating blood vessels that can be used for dialysis patients and in heart bypass surgery. Now, three years after forming Humacyte, a Research Triangle Park company, to pursue their research, the three women are a year or two away from testing their blood vessels in patients.

"This is a huge deal," said Dr. Alan Kypson, a heart surgeon at East Carolina University who has tested Humacyte's product in dogs.

"It sounds sci-fi," Kypson added. "This is something that really hasn't been done before. But done appropriately, it would be of great benefit."

Currently vascular grafts -- pieces of blood vessel that reroute the flow of blood -- are either made from synthetic materials or harvested from the patient. More than 500,000 patients in the United States each year have such grafts surgically implanted. They are used to bypass blood clots near the heart and in the legs and ease access for dialysis, a procedure that regularly washes the blood of patients whose kidneys have failed.

But synthetic grafts and those harvested from the patient's body, usually the leg, have severe limitations. About half of all dialysis patients need replacements of their synthetic grafts every six months. Heart patients, who rely on harvested grafts, run out of options after six or seven bypasses.

Engineered vascular grafts promise to prolong lives, cut medical costs and reduce time in the operating room. And the company that offers surgeons such a solution could take aim at a $1 billion market, said Geoffrey Erickson, Humacyte's chief executive and a biomedical engineer by training.

Humacyte isn't the only company after that market.

Cytograft Tissue Engineering, a California company, is Humacyte's biggest competitor. It uses patients' own cells to grow vascular grafts.

Cytograft has begun to test its technology in a few dialysis patients. The company is also trying to develop a product that would be less expensive and more efficient than growing an individual graft for each patient.

Humacyte already has such a product. It can be stored at room temperature and used in any patient. So far, grafts made from dog cells and tested in dogs have worked for one year. The company is now testing grafts made from human cells in baboons. Niklason expects their research will move to dialysis patients in about a year or two.

Tests on heart bypass patients could begin in five to seven years, she said.

It took persistence, dedication and hours in the lab for Niklason, and then Blum and Dahl, to get where they are.

"In a startup, you're never really off," said Dahl, who gave birth to a son a year ago. Blum had her first child, a daughter, a few weeks ago.

Niklason, who is the mother of two, counts the research as her third child.

"It's my life's work," she said.

Niklason is a disciple of Robert Langer, a chemical engineering professor at the Massachusetts Institute of Technology and one of the fathers of tissue engineering. She worked in Langer's lab from 1995 until she joined Duke in 1998. It was at MIT that her interest in blood vessels was piqued.

At Duke, she continued her research and began working with Dahl. The two, working off Niklason's previous work, developed a method to use human cells from blood banks to grow tubes of collagen, a protein that the body makes to hold cells together. By killing the cells, they determined, the tubes could be stored at room temperature and used in any patient.

Blum joined Niklason's lab shortly thereafter. About a year later, the three started Humacyte and proved their method works.

They still have to show the grafts work in patients and function longer than a year. Scaling up production also remains a hurdle. But for the moment, the three, along with their other seven employees, are working on fine-tuning their research.

And nobody is laughing at Niklason anymore.