Though mending damaged hearts with a patch of heart muscle may sound like the stuff of sci-fi movies, Dr. Michael Sefton said such treatments may become commonplace within ten years. He even thinks engineered human hearts, created from scratch (read: stem cells) may become a reality within 20.

Sefton, former director of U of T’s Institute of Biomaterials and Biomedical Engineering (IBBME), pioneered the field of tissue engineering-the concept of mixing cells with man-made materials. He received an Sc.D. from MIT in 1974, and came to U of T shortly thereafter.

Early in his career, he developed procedures for microencapsulating mammalian cells for the purposes of transplantation. Although the task turned out to be more challenging than initially thought, it wasn’t in vain. “In hindsight, this turned out to be one of the origins of what is now called tissue engineering,” Sefton said.

Possible applications for tissue engineering run the gamut, ranging from wound healing to whole organ transplants. Sefton explained its idea in the context of one application: making a muscle patch that could be used to mend a broken heart.

“The simple way that tissue engineering works is to take cells, cardiomyocytes, and put them in a plastic matrix. You allow the cardiomyocytes to grow, the matrix degrades or is replaced by cardiomyocytes, and you end up with a chunk of heart muscle. That chunk of tissue would then be sewn on as a patch onto a damaged heart, the idea being that the patch would do some of the work that the damaged heart couldn’t.”

With several such treatments currently in clinical trials, Sefton predicts they may see widespread use within ten years. Meanwhile, he has been working on other stuff.

“Over the last five to ten years we have thought about biomaterials in a different way. We think of them as three-dimensional drugs, as solid objects causing the same kind of biological responses [as drugs].” Sefton’s sense of observation led him to discover a polymer that induces blood vessel growth, or angiogenesis.

This process is extremely valuable in wound healing, after transplants. A primary worry there is getting nutrients to transplanted tissues, allowing them to integrate into the rest of the organism.

Although the field of tissue engineering is relatively new, Sefton is optimistic about its progress. “Tissue engineering has been technically successful in the skin and in bone and cartilage. I think over the next 10 to 20 years we’ll see more of these tissues emerging into the clinic and be available for patients.” He also thinks that the answer lies in combining tissue engineering with other technologies.

“Tissue engineering is being encompassed now in a larger field called regenerative medicine, which includes gene therapy and stem cell [technology]. They all have the same general purpose: to repair or replace human tissues. That’s probably what we will see, not tissue engineering by itself, but tissue engineering in conjunction with gene therapy.”