Tel Aviv scientists have invented a bionic patch for the heart, consisting of electronically-regulated living tissue, which they hope can obviate the need for heart transplants in at least some patients. So far testing of the smart cyborg tissue has been confined to rats, where the results have been positive.
The concept is to create "smart tissue" that helps the heart beat and reacts when malfunction occurs, explains the team, headed by Dr. Tal Dvir, in a paper published in Nature Materials on Monday. Finally scientists can start talking about engineering "self-regulating tissue," which Dvir dubs “cyborg tissue” because it combines living and mechanical elements.
“At this point, we have developed heart muscle tissue with enhanced capabilities,” Dvir told Haaretz. “The idea is to create a complete heart with living tissue that integrates nano-electronics to preserve it in a good functioning state.”
The cardiac patch is made of heart muscle cells, biomaterial and nano-composite fibers that enable the engineered-tissue function to be monitored online. The extracellular matrix connects the cells chemically, mechanically and electrically. The tissue becomes part of a larger system that includes algorithms for managing heart failure.
“In practice, the extracellular matrix turns the collection of cells into functioning tissue,” explained Dvir. “We in the lab are trying to synthetically reproduce the extracellular matrix. We learn the various traits of the biological tissue, and then use reverse engineering.”
Print me a heart
The team is also working on an equally ambitious project to print a complete bionic heart — including atria, chambers, valves and blood vessels, alongside miniature electronic components — using a 3-D printer.
Heart disease is the leading cause of death in the West. “Statistics show that 50 percent of those who suffered serious heart attacks will die within five years,” says Dvir. “What we are trying to do is invent alternative tissues to internal organs in general, and to engineer heart tissue specifically. Today, if somebody suffers a serious heart attack, there is not much to do other than perform a heart transplant. Since there’s a shortage of donors, we’re trying to engineer new alternatives in our lab — and build new tissues.”
The waiting list for heart transplants in Israel at the end of last year was 73. (The list is restricted to people aged less than 65.)
Electronics in tissue
The idea behind integrating electronic components into engineered tissue, which Dvir is doing with grad student Ron Feiner, is to monitor heart activity online using nano-electronics, "and when necessary regulate the engineered tissue activity — and even to release drugs at the push of a button with the help of special polymers we developed,” says Dvir.
“For example, if the tissue signals that inflammation has developed, we can release an anti-inflammatory drug. If the tissue reports a lack of oxygen, we can release bio-factors that attract stem cells to build additional blood vessels, all in real time. The patient is sitting at home and doesn’t feel well. The doctor receives a beeper message, logs on and sees the heart’s condition. He decides what to do from afar,” he says.
The initial testing was conducted on rats. “The signaling system worked well. We succeeded in receiving information on heart activity via the computer, controlling the heart’s rate and carrying out other activities,” said Dvir. The next testing stage is on pigs, in the hope that they’ll pave the way for clinical trials on humans.
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