Engineers at the University of Toronto just made assembling functional heart tissue as easy as fastening your shoes. The team has created a biocompatible scaffold that allows sheets of beating heart cells to snap together just like Velcro™.
“One of the main advantages is the ease of use,” says Professor Milica Radisic (ChemE, IBBME), who led the project. “We can build larger tissue structures immediately before they are needed, and disassemble them just as easily. I don’t know of any other technique that gives this ability.”
Growing heart muscle cells in the lab is nothing new. The problem is that too often, these cells don’t resemble those found in the body. Real heart cells grow in an environment replete with protein scaffolds and support cells that help shape them into long, lean beating machines. In contrast, lab-grown cells often lack these supports, and tend to be amorphous and weak. Radisic and her team focus on engineering artificial environments that more closely imitate what cells see in the body, resulting in tougher, more robust cells.
Two years ago, Radisic and her team invented the Biowire, in which heart cells grew around a silk suture, imitating the way real muscle fibres grow in the heart. “If you think of single fibre as a 1D structure, then the next step is to create a 2D structure and then assemble those into a 3D structure,” says Boyang Zhang a PhD candidate in Radisic’s lab. Zhang and Miles Montgomery, another PhD student in the lab, were co-lead authors on the current work, published today in Science Advances.
Developing an efficient way to freeze and store living tissues could transform many aspects of medical care and research
Developing an efficient way to freeze and store living tissues could transform many aspects of medical care and research, but ice crystallization often occurs within cells during such cryopreservation procedures, leading to cell death. In the November 5 issue of the Biophysical Journal, a Cell Press publication, researchers report that they have gained new information about the processes that are responsible for promoting the freezing of cells within tissues. This knowledge may ultimately lead to novel approaches for preventing tissue injury during cryopreservation.
A long-standing obstacle to avoiding tissue damage during freezing is that when cells are joined together within tissues, individual cells are more likely to crystallize than if the cells are kept apart. “In tissues, ice crystals are thought to be able to grow through membrane channels called gap junctions, thus allowing ice to easily propagate from cell to cell,” explains senior author Dr. Jens Karlsson, of the Department of Mechanical Engineering at Villanova University. “But the results of the present study indicate that the mechanism of tissue cryo-injury is much more complex than was previously thought.”