ETH scientists have developed a special protective membrane made of cellulose that significantly reduces the build-up of fibrotic tissue around cardiac pacemaker implants, as reported in the current issue of the journal Biomaterials. Their development could greatly simplify surgical procedures for patients with cardiac pacemakers.
"Every pacemaker has to be replaced at some point. When this time comes, typically after about five years when the device's battery expires, the patient has to undergo surgery," explains Aldo Ferrari, Senior Scientist in ETH Professor Dimos Poulikakos's group and at Empa. "If too much fibrotic tissue has formed around the pacemaker, it complicates the procedure," he explains. In such cases, the surgeon has to cut into and remove this excess tissue. Not only does that prolong the operation, it also increases the risk of complications such as infection.
Microstructure reduces fibrotic tissue formation
To overcome this issue, Ferrari and his colleagues at ETH Zurich spent the last few years developing a membrane with a special surface structure that is less conducive to the growth of fibrotic tissue than the smooth metal surface of pacemakers. This membrane has now been patented and Ferrari is working with fellow researchers at the Wyss Zurich research center, the University of Zurich and the German Center of Cardiovascular Research in Berlin to make it market-ready for use in patients.
As part of this process, the research consortium has now tested the membrane on pigs. In each pig, the scientists implanted two pacemakers, one of which was enveloped in the cellulose membrane.
Following the one-year test period, the researchers can report positive results: the pigs' bodies tolerate the membrane and do not reject it. "This is an important finding because tolerance is a core requirement for implant materials," Ferrari says. Just as importantly, the membrane did what it was supposed to: the fibrotic tissue that formed around it was, on average, only a third as thick as the tissue that formed around the unencapsulated pacemakers.
Next step: Clinical trials
The scientists attribute this reduction in fibrotic tissue formation in the first stage to the material itself - cellulose is fibrous by nature. "When fibrotic tissue forms, the first stage is the deposition of proteins on the surface. A fibrous membrane surface impedes this process," explains Francesco Robotti, lead author of the study and a scientist in ETH Professor Poulikakos's group. Another factor is that the researchers created the membrane with honeycomb-like indentations in the surface, each measuring 10 micrometres in diameter. "These indentations make it difficult for the cells that form fibrotic tissue to adhere to the surface - the second stage in the formation processes," Robotti says.
Now that the material has proved successful in animal trials, the scientists plan to apply for approval for clinical trials in humans in partnership with the ETH spin-off Hylomorph, which will be responsible for commercialisation of the membrane. The trials are slated to start next year at three large cardiac centres in Germany.
This work was carried out as part of University Medicine Zurich's flagship Zurich Heart project and ETH+ project ETHeart.
Robotti F, Sterner I, Bottan S, Monné Rodríguez JM, Pellegrini G, Schmidt T, Falk V, Poulikakos D, Ferrari A, Starck C: Microengineered biosynthesized cellulose as anti-fibrotic in vivo protection for cardiac implantable electronic devices, Biomaterials 2019, 229: 119583, doi: 10.1016/j.biomaterials.2019.119583
Francesco Robotti | EurekAlert!
Lung images of twins with asthma add to understanding of the disease
06.12.2019 | University of Western Ontario
Between Arousal and Inhibition
06.12.2019 | Albert-Ludwigs-Universität Freiburg im Breisgau
Using a clever technique that causes unruly crystals of iron selenide to snap into alignment, Rice University physicists have drawn a detailed map that reveals...
University of Texas and MIT researchers create virtual UAVs that can predict vehicle health, enable autonomous decision-making
In the not too distant future, we can expect to see our skies filled with unmanned aerial vehicles (UAVs) delivering packages, maybe even people, from location...
With ultracold chemistry, researchers get a first look at exactly what happens during a chemical reaction
The coldest chemical reaction in the known universe took place in what appears to be a chaotic mess of lasers. The appearance deceives: Deep within that...
Abnormal scarring is a serious threat resulting in non-healing chronic wounds or fibrosis. Scars form when fibroblasts, a type of cell of connective tissue, reach wounded skin and deposit plugs of extracellular matrix. Until today, the question about the exact anatomical origin of these fibroblasts has not been answered. In order to find potential ways of influencing the scarring process, the team of Dr. Yuval Rinkevich, Group Leader for Regenerative Biology at the Institute of Lung Biology and Disease at Helmholtz Zentrum München, aimed to finally find an answer. As it was already known that all scars derive from a fibroblast lineage expressing the Engrailed-1 gene - a lineage not only present in skin, but also in fascia - the researchers intentionally tried to understand whether or not fascia might be the origin of fibroblasts.
Fibroblasts kit - ready to heal wounds
Research from a leading international expert on the health of the Great Lakes suggests that the growing intensity and scale of pollution from plastics poses serious risks to human health and will continue to have profound consequences on the ecosystem.
In an article published this month in the Journal of Waste Resources and Recycling, Gail Krantzberg, a professor in the Booth School of Engineering Practice...
03.12.2019 | Event News
15.11.2019 | Event News
15.11.2019 | Event News
09.12.2019 | Earth Sciences
09.12.2019 | Information Technology
09.12.2019 | Life Sciences