Regenerative body parts in the works
A Canadian researcher is hoping that within ten years, people will be able to regrow tendons, spinal cords or heart valves lost to injury or disease. Dr. Brian Amsden, a chemical engineering professor from Queen’s University, is developing a technique wherein cells from a patient’s body would be placed on a polymer prosthetic that stimulates cell growth. After the cells had established themselves sufficiently, the prosthetic would be implanted in the patient’s body. The polymer would then biodegrade, leaving behind nothing but the patient’s own tissue.
Not unlike Dr. Jeremy Mao’s system for growing teeth, Dr. Amsden’s system involves seeding cells onto a three-dimensional scaffold that mimics the structure of the desired part. In Amsden’s case, that structure is made up of spun polymer nanofibers, each one with a diameter smaller than that of a single cell.
Already, he has succeeded in getting fibroblasts (cells that make up collagen) to grow along the length of such a scaffold, simulating a tendon or ligament. Collagen in such body parts has a crimped structure, which allows it to stretch without breaking. To replicate that crimp in his DIY tendon/ligament, Amsden spun and aligned some nanofibers on a wire mandrel, which is essentially a spinning axle. When the tightly-wound fibers were pulled off the mandrel, they shrunk in length, producing a scaffold with the desired crimped structure. The collagen that subsequently grew along the fibers was also accordingly crimped.
Amsden and his team at Queen’s are now looking into using stem cells harvested from the patient’s own fat, and the possible use of bioreactors that could stimulate tissue regeneration.