Ideally, patients wouldn't need a doctor and the cyborg hearts beating in their chests will operate themselves.
In the foreseeable future, heart patients will walk among us with hearts that have brains. Tel Aviv University researchers recently presented impressive progress in what one might call the "bionic heart."
In research published in Nature Materials on Monday, the team, headed by Dr. Tal Dvir, presented their new development: Smart tissue will be transplanted into patients, which will be able to monitor and regulate tissue function. It will help the heart beat and intervene when it's not functioning properly, and provide an exact and regular report to the patient and cardiologist.
The tissue, which is interwoven with electronic particles, will also know how and when to release anti-inflammatory drugs - all in real time.
Dvir and his team also revealed the first tissue of this bionic heart. At this stage, it is a cardiac patch that's made of heart muscle cells, biomaterial and nano-composite fibers that allow online monitoring of the engineered-tissue function. The tissue itself is part of a larger system that includes algorithms for managing heart failure.
"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."
In parallel, the team has also started work on an equally ambitious project using a 3-D printer to print a complete bionic heart - including atria, chambers, valves and blood vessels, alongside miniature electronic components.
Heart diseases are the leading cause of death in the West, with heart attacks being most prevalent. "Statistics show that 50 percent of those who suffered serious heart attacks will die within five years," noted 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 those below the age of 65.)
In general, the tissue is made up of cells and an extracellular matrix, which connect the cells chemically, mechanically and electrically.
"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."
The latest and most ambitious development by Dvir and doctoral student Ron Feiner is integrating electronic components into engineered tissue. "The idea 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," said Dvir.
"For example, if the tissue signals that there is an inflammation, 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."
Ideally, the patient doesn't need a doctor and the bionic heart that's beating in his chest operates itself. "You can write him a program, code that shows him how to act," said Dvir. "For example, when the engineered tissue feels less than 60 contractions a minute, it delivers the signal to contract at the desired frequency. You don't need to wait for a doctor."
Dvir believes the research allows scientists to finally start talking about engineering self-regulating tissue, which he calls "cyborg tissue" because it combines living and mechanical elements.
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.