Swedish researchers have developed nanoparticles that comprise a temporary cardiac stimulator when injected into the pericardial cavity of a person undergoing cardiac arrest or life-threatening arrhythmia. The injectable cardiac stimulator can be connected to a mobile phone and can resuscitate the person, keeping them alive. A researcher says that the invention, which has so far only been tested in animals, can be used both in war zones and when people with heart problems need to be transported over long distances to get help.
Most people with a heart problem would prefer to be near a hospital or at least near a defibrillator, but this is not always possible.
Some people may experience life-threatening arrhythmia or cardiac arrest far from medical facilities, such as in a war zone or in a low-income country a long way from hospital and the necessary equipment to save a person with a challenged heart.
Situations such as these have cost many lives, but the future may look different now that Swedish researchers have designed a unique solution comprising nanoparticles in a syringe. Once injected into the pericardial cavity, the nanoparticles form a conductive polymer around the heart to enable cardiac stimulation.
Some polymers are excellent conductors of electricity, so connecting the nanoparticles to a mobile phone can restart the heart and keep it going until help arrives. Thus, whether a person can be operated on or receive heart medication within five hours or five days is not so critical. The stimulator formed from soluble nanoparticles can keep the heart going until then.
“Our original intention was to develop something that can be used in a war zone if combatants have cardiac arrest or life-threatening arrhythmia far from a medical facility and help. But our solution can also be used by people on a long hike or in low-income countries, where many days of travel are required to get to the nearest hospital with the facilities to resuscitate a person with a heart condition. In these situations, the nanoparticle solution can be injected around the heart and act as a temporary pacemaker,” explains a researcher behind the development of the injectable cardiac stimulator, Roger Olsson, Professor, Department of Experimental Medical Science, Lund University and Department of Chemistry and Molecular Biology, University of Gothenburg, Sweden.
The research has been published in Nature Communications.
Nanoparticle solution forms a conductive structure around the heart
Roger Olsson explains that the nanoparticles bind ions in the heart tissue and form a hydrogel that can conduct electricity.
The long-term idea is to inject the nanoparticles into a person’s pericardial cavity, and pulling out the needle creates a nanoparticle cable that can be connected to an external power source, such as a mobile phone.
The cardiac stimulator does not require more power than a mobile phone can supply because the conductive structure formed from the nanoparticles is very close to but not in the heart.
The researchers are already examining the possibility of developing an app that can regulate heartbeat, rectify arrythmia or give the heart a life-saving shock.
“Further, the nanoparticles are bioresorbable. This means that surgery is not required to get them out; they will instead be spontaneously excreted by the body,” says Roger Olsson.
Testing in pigs
The researchers have already tested the conductive hydrogel in zebrafish (Danio rerio) and in a chicken embryo heart model and have shown that the nanoparticles function as intended.
Injecting the nanoparticles into the pericardial cavity of the animals and connecting an external power source enabled the researchers to regulate heartbeat in vivo.
The next step in the research will be to investigate whether the nanoparticles also work in larger mammals, such as pigs, which have similar hearts to humans.
However, does this mean that injectable cardiac stimulators will be ready for next summer’s hike? Not according to Roger Olsson, who says that turning the technique into reality will take some time.
“We have long worked to get the nanoparticles to behave as we would like them to, but having a finished product will also take several years,” concludes Roger Olsson.
“In situ assembly of an injectable cardiac stimulator” has been published in Nature Communications. The research was supported by the Swedish Research Council, the Swedish Foundation for Strategic Research, the European Research Council and a Distinguished Innovator Grant from the Novo Nordisk Foundation.
