Scientists in China and Switzerland have teamed up to produce an implantable medical device that mimics the primary function of blood vessels, but goes a number of steps further than its natural counterparts. These electronic blood vessels can be used to facilitate the flow of blood, as demonstrated in rabbits, but could also be configured to assist in drug delivery, wound healing and even gene therapy.
For a number of years, scientists have been working to bioengineer blood vessels that could help us study diseases, treat folks with kidney failure or replace blocked vessels in sufferers of cardiovascular disease. The researchers behind this new study, however, sought to expand on these types of “passive” scaffolds and mechanical supports with versions that play an active role in a patient’s recovery.
Their electronic blood vessels are made using a cylindrical rod to roll up a metal-polymer conductor membrane. These devices are flexible, biodegradable and contain circuitry that can be coordinated with other electronic devices to take on different tasks, such as electronically controlled drug delivery.
In one experiment, the scientists showed how electrically stimulating the blood vessel in a wound healing model could boost the proliferation and migration of endothelial cells, which line the interior surface of natural blood vessels, indicating it could be used to build new tissue. In another laboratory experiment, the team hooked the electronic blood vessel up to a device that creates an electrical field to make cells more permeable. This enabled the team to deliver green fluorescent protein DNA into three different types of blood vessel cells.
The researchers then turned their attention to in vivo studies, using the electronic blood vessel to replace a key artery in rabbits that supplies blood to the brain, neck and face. The device was monitored over three months, with the scientists reporting it allowed for sufficient blood flow the entire time. Analysis of the rabbits' internal organs after the implants had been removed revealed no signs of inflammation.
From here, the team hopes to build on these promising early results with further studies on rabbits to establish the long-term safety of the device. Another consideration is that the other electronic devices paired with the electronic blood vessel would need to be scaled down were the approach to be used in humans.
"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 lead author Xingyu Jiang, a researcher at Southern University of Science and Technology and the National Center for NanoScience and Technology in China.
The research was published in the journal Matter.
Source: Cell Press via EurekAlert
