Her friends jokingly call her “the fat lady.” That’s because Julie Fradette’s dream is to extract stem cells from fat, coax them in her lab to divide and grow, create all-natural three-dimensional soft tissue, and have surgeons use it in people’s bodies. She’s done all but the last. When that happens, a new breast could be built or a gaping wound filled without any synthetic material whatsoever—just the person’s own cells. “That’s the beauty of it,” says Fradette. And using adult cells avoids the question of embryonic stem cells, the source of a lot of the controversy.
Fradette, a researcher at the cutting-edge Laboratoire D’Organogénèse Expérimentale (LOEX) at Université Laval in Quebec City, is a world leader in creating three-dimensional soft tissue that is completely autologous, meaning from the self. Her colleagues at LOEX use stem cells—mostly harvested from skin—to produce new skin, blood vessels, ligaments, bronchi and corneas. And other groups have taken fat and re-injected it elsewhere in the body—to fill in facial wrinkles, for instance. Fradette is unique in using fat stem cells to create larger chunks of tissue.
Her experiments use fat that has been cut or liposuctioned from people’s bellies and butts at nearby clinics. (The donors have consented to have their fat used.) But one day, she hopes to rely on a patient’s own fat cells. “It is possible to harvest your stem cells from fat even if you are thin,” she explains. “We have a lot of it, and it’s so accessible.”
Here’s how it works: she takes about a cup of fat, puts enzymes in it, and spins it in a centrifuge to get rid of the cells she doesn’t need. (Think of fat cells as grapes on a vine. The grapes are the adipocytes—the main cells that store fat. The useful stem cells are found in the stroma—the vine.) After the spinning procedure, the adipocytes float to the surface and are discarded; the stroma stem cells form a blob at the bottom of the tube. “When I have enough,” she explains, “I put them on a plate to be cultured, stimulate them with an induction cocktail that includes vitamin C, and they start forming a sheet.” After a few weeks, Fradette lifts the sheet with forceps and superimposes it on other sheets, eventually forming a chunk of tissue that is strong, but soft enough to be customized. “Ultimately, we can have the shape we want and the thickness we desire,” she says.
To build a large chunk of tissue, you need a “scaffold” or a 3-D structure, usually built from material such as sponges or collagen. Her team is the first to develop an all-natural structure the body won’t reject. “The biomaterial is made from your cells so it is the best possible match,” she says. A Korean researcher at an international meeting, after hearing about this work, observed, “Not using any scaffold? It would be wonderful.” The soft tissue will be used for people who have lost flesh due to accidents, burns, animal bites, face wounds, surgery, even radiation.
Fradette expects it will be at least 10 years before surgeons can graft her tissue onto patients. The procedure is in preclinical trials in mice at LOEX. Meanwhile, they have surmounted another hurdle: adding capillaries to the tissue, which helps the blood flow faster once it is grafted. “That’s the big challenge,” she says. When Fradette realizes her dream, she’ll be building tissue for those who require it. She’ll make as much as they need, and it’ll be recycled from a commodity that grows in great abundance. As Lucie Germain, scientific director of LOEX, puts it: “It’s easy to get fat from a person. Nobody is reluctant to give up their fat!”