Researchers at the University of Toronto have developed a machine that creates layered engineered tissue that could be used as grafts for burn victims or vascular patches.
“There’s a lot of interest in soft materials, particularly biomaterials,” says Associate Professor Axel Guenther of the university’s Department of Mechanical and Industrial Engineering who helped create functional tissue cultures, which was research conducted under the auspices of the university’s Institute of Biomaterials and Biomedical Engineering. “But until now no one has demonstrated a simple and scalable one-step process to go from microns to centimeters.”
The machine grows large patches of living tissue by manipulating biopolymers. The mixing of the materials causes a chemical reaction that forms a “mosaic hydrogel.” That hydrogel is a sheet-like substance that is compatible with the growth of cells into living tissue, much like how different types of cells can be seeded in precise and controlled placements.
What is unique to tissue engineering is the timing of certain stages of the manufacturing. The cells are planted onto the mosaic hydrogel sheets at precisely the time that they are created. The researchers believe this approach generates the perfect conditions for cells to grow. The university’s press release announcing the development explains further:
The placement of the cells is so precise, in fact, that scientists can spell words (such as ‘Toronto,’ shown in diagram) and can precisely mimic the natural placement of cells in living tissues. And by collecting these sheets around a drum, the machine is able to collect layers of cells in thicknesses made to measure: in essence, three dimensional, functional tissues.
Cell placement is key, the researchers say. “”The cells are able to stretch and connect with each other, which is very important for ultimately obtaining functional tissues,” Guenther says.
The resulting tissues, says Lian Leng, lead author on the project, are remarkably stable. “In this case, when we put the cells in the right places we create cellular organization quite naturally,” he says.
The researchers hope to build upon the innovation and create three-dimensional cell cultures that could develop into therapeutic drugs. Their work has been published in Advanced Materials.
Source: “From Microns to Centimeters — IBBME Researchers Invent New Tissue Engineering Tool,” University of Toronto press release, undated.
Image by Lian Leng, University of Toronto, used with permission.
Dale McGeehon has been a journalist and editor for more than 25 years, covering chemical regulation and testing for Pesticides and Toxic Chemical News and innovations in material sciences for the National Technology Transfer Center. His writing credits include Omni and College Park magazines and The New York Times.