biocompatible polymer
Photo courtesy of Vienna
University of Technology
Scientists have created implantable artificial blood vessels using a newly developed polymer that is biodegradable.
In experiments with rats, these thin-walled vascular grafts were replaced by endogenous material, ultimately leaving natural, fully functional blood vessels in their place.
Furthermore, 6 months after the artificial vessels were implanted, none of the animals had experienced thromboses, inflammation, or aneurysms.
Helga Bergmeister, MD, DVM, PhD, of the Medical University of Vienna in Austria, and her colleagues conducted this research and described the results in Acta Biomaterialia.
To create artificial blood vessels that are compatible with body tissue, the researchers developed a new polymer—thermoplastic polyurethane.
“By selecting very specific molecular building blocks, we have succeeded in synthesizing a polymer with the desired properties,” said Robert Liska, PhD, of the Vienna University of Technology.
To produce the grafts, the researchers spun polymer solutions in an electrical field to form very fine threads and wound these threads onto a spool.
“The wall of these artificial blood vessels is very similar to that of natural ones,” said Heinrich Schima, PhD, of the Medical University of Vienna.
The polymer fabric is slightly porous. So, initially, it allows a small amount of blood to seep through, which enriches the wall with growth factors. And this encourages the migration of endogenous cells.
The researchers implanted these artificial blood vessels in rats and found them to be safe and functional long-term.
“The rats’ blood vessels were examined 6 months after insertion of the vascular prostheses,” Dr Bergmeister said.
“We did not find any aneurysms, thrombosis, or inflammation. Endogenous cells had colonized the vascular prostheses and turned the artificial constructs into natural body tissue.”
In fact, natural body tissue regrew much faster than expected.
The researchers said their thin-walled grafts “offer a new and desirable form of biodegradable vascular implant.”
