(Medical Xpress)—Researchers at MIT and Charles Stark Draper Laboratory have developed a method of growing living 3-D tissue using a modified version of a machine normally used to build integrated circuits. In their paper published in the journal Advanced Materials, the group describes how they built customized scaffolding that allowed for the growth of functional three dimensional heart tissue—a technique that could one day lead to a means for growing artificial organs.
Up till now, researchers have been able to grow sophisticated tissue in two dimensions and very simple tissues in three. In this new effort, the researchers used technology from the microelectronics industry to build scaffolding that allowed for growth of highly sophisticated heart tissue in ways that mimic nature.
When growing tissue in three dimensions, a way must be found to cause it to grow in certain ways, rather than as simple blobs—otherwise it won't function as it would naturally. With the heart for example, fibrous tissue must line up to allow for squeezing in just the right way to force blood through the chambers of the heart. To artificially reproduce such tissue the researchers modified a device that normally allows for stacking thin materials onto circuit boards. In their lab, the machine allows for stacking a flat rubber polymer with holes in it on top of another in such a way as to align the holes in just the right way to cause heart cells to grow through them into the types of fibers that mimic normal heart tissue—a type known as anisotropy.
Positioning several of the rubber sheets, one on top of another, allowed for the growth of three-dimensional tissue that mimics tissue naturally found in the heart. Once grown, the tissue was found to beat in response to electrical stimulation.
At this point, the heart tissue grown is still too thin to support blood vessels, so further research will have to be done to find a way to make it thicker. In the meantime, the researchers plan to apply some of the newly grown tissue to rat hearts that have been damaged to see if it can help serve as a repair material.