Since we need new blood vessels to support either neurogenesis or stem cells this might become useful to our recovery. Ask your stroke association to sponsor research to figure out how to solve this for helping survivors.
http://www.alphagalileo.org/ViewItem.aspx?ItemId=152126&CultureCode=en
Blocked blood vessels can quickly become dangerous. It is often
necessary to replace a blood vessel – either by another vessel taken
from the body or even by artificial vascular prostheses. Together,
Vienna University of Technology and Vienna Medical University have
developed artificial blood vessels made from a special elastomer
material, which has excellent mechanical properties. Over time, these
artificial blood vessels are replaced by endogenous material. At the end
of this restorative process, a natural, fully functional vessel is once
again in place. The method has already been used successfully in rats.
Arteriosclerotic vascular disorders are one of the most common causes
of death in industrialized countries. In this situation a bypass
operation is often the only solution. Normally, blood vessels are taken
from another part of the patient's body and used to replace the damaged
vessel. Thanks to a joint project undertaken by TU Wien and the Medical
University of Vienna, artificially manufactured vessels should be used
more frequently in future.
The most important thing is to find a suitable material. The
artificial materials that have been used so far are not ideally
compatible with body tissue. The blood vessel can easily become blocked,
especially if it is only small in diameter.
TUW has therefore developed new polymers. "These are so-called
thermoplastic polyurethanes," explains Robert Liska from the Institute
of Applied Synthetic Chemistry of Vienna University of Technology. "By
selecting very specific molecular building blocks we have succeeded in
synthesizing a polymer with the desired properties."
A thin polymer thread spun into tubes
To produce the vascular prostheses, polymer solutions were spun in an
electrical field to form very fine threads and wound onto a spool. "The
wall of these artificial blood vessels is very similar to that of
natural ones," says Heinz Schima of the Medical University of Vienna.
The polymer fabric is slightly porous and so, initially, allows a small
amount of blood to permeate through and this enriches the wall with
growth factors. This encourages the migration of endogenous cells. The
interaction between material and blood was studied by Martina
Marchetti-Deschmann at TU Wien using spatially resolved mass
spectrometry.
The new method has already proved very successful in experiments with
rats. "The rats' blood vessels were examined six months after insertion
of the vascular prostheses," says Helga Bergmeister of MedUni Vienna.
“We did not find any aneurysms, thromboses or inflammation. Endogenous
cells had colonized the vascular prostheses and turned the artificial
constructs into natural body tissue." In fact, natural body tissue
re-grew much faster than expected so that the degradation period of the
plastic tubes can be even shorter. Further adaptations are currently
being made to the material.
The project was recently awarded PRIZE prototype funding from Austria
Wirtschaftsservice (AWS). A few more preclinical trials are necessary
before the artificial blood vessels can be used in humans. However,
based on the results so far, the research team is very confident that
the new method will prove itself for use in humans in a few years time.
http://www.meduniwien.ac.at
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