Flexible and biodegradable electronic blood vessels

Date:
October 1, 2020
Source:
Cell Press
Summary:
Researchers have developed electronic blood vessels that can
be actively tuned to address subtle changes in the body after
implantation. The blood vessels -- made of a metal-polymer conductor
membrane that's flexible and biodegradable -- mimic natural blood
vessels, were conductive in in vitro experiments, and were able
to effectively replace key arteries in rabbits.



FULL STORY ========================================================================== Researchers in China and Switzerland have developed electronic blood
vessels that can be actively tuned to address subtle changes in the body
after implantation. The blood vessels -- made of a metal-polymer conductor membrane that's flexible and biodegradable -- mimic natural blood vessels,
were conductive in in vitro experiments, and were able to effectively
replace key arteries in rabbits. The research, published October 1 in the journal Matter, could overcome the limitations of conventional tissue engineered blood vessels (TEBVs), which serve as passive scaffolds, by coordinating with other electronic devices to deliver genetic material,
enable controlled drug release, and facilitate the formation of new
endothelial blood vessel tissue.


==========================================================================
"We take the natural blood vessel-mimicking structure and go beyond it
by integrating more comprehensive electrical functions that are able
to provide further treatments, such as gene therapy and electrical stimulation," says lead author Xingyu Jiang, a researcher at Southern University of Science and Technology and the National Center for
NanoScience and Technology in China.

Previous research has developed a variety of TEBVs that provide mechanical support for hard-to-treat blockages of tiny blood vessels in patients
with cardiovascular disease. But these TEBVs have limitations: they
cannot proactively assist in regenerating blood vessel tissue and,
unlike natural tissue, often cause inflammation in response to blood
flow. "None of the existing small-diameter TEBVs has met the demands of treating cardiovascular diseases," says Jiang.

To surpass the limitations of existing technologies, Jiang and
colleagues fabricated biodegradable electronic blood vessels using
a cylindrical rod to roll up a metal-polymer conductor membrane made
from poly(L-lactide-co-e- caprolactone). They showed that, in the lab, electrical stimulation from the blood vessel increased the proliferation
and migration of endothelial cells in a wound healing model, suggesting
that electrical stimulation could facilitate the formation of new
endothelial blood vessel tissue. The researchers also integrated the
blood vessels' flexible circuitry with an electroporation device, which
applies an electrical field to make cell membranes more permeable, and
observed that the combined technologies successfully delivered green fluorescent protein DNA into three kinds of blood vessel cells in the lab.

Next, the researchers tested the device in New Zealand rabbits, replacing
their carotid arteries -- which supply blood to the brain, neck, and
face -- with electronic blood vessels. Jiang and colleagues monitored
the implants using doppler ultrasound imaging over the course of three
months, finding that the device allowed for sufficient blood flow the
entire duration. Imaging tests that use X-rays and dye to peer inside
arteries revealed that the artificial arteries appeared to function
just as well as the natural ones had, with no sign of narrowing. When
the researchers removed the implants and analyzed the rabbits' internal
organs at the end of the three-month period, they discovered no evidence
that the devices had produced an inflammatory response.

While these electronic blood vessels demonstrated promise as surrogate
arteries in rabbits, Jiang acknowledges that more work must be done before
the technology will be ready for human trials, including long-term safety
tests in larger cohorts of rabbits and other animals. Additionally,
in order to be suitable for long-term implantation, the electronic
blood vessels would need to be paired with smaller electronics than the electroporation device used in this study.

"In the future, optimizations need be taken by integrating it with
minimized devices, such as minimized batteries and built-in control
systems, to make all the functional parts fully implantable and even fully bio-degradable in the body," says Jiang. The researchers also hope that
this technology could someday be combined with artificial intelligence to collect and store detailed information on an individual's blood velocity,
blood pressure, and blood glucose levels.


========================================================================== Story Source: Materials provided by Cell_Press. Note: Content may be
edited for style and length.


========================================================================== Journal Reference:
1. Shiyu Cheng, Chen Hang, Li Ding, Liujun Jia, Lixue Tang, Lei Mou,
Jie Qi,
Ruihua Dong, Wenfu Zheng, Yan Zhang, Xingyu Jiang. Electronic
Blood Vessel. Matter, 2020; DOI: 10.1016/j.matt.2020.08.029 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/10/201001113634.htm

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